1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager 1.113.5 Setup and configure basic DNS services Weight 4 Linux Professional Institute Certification — 102 Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND Andrew Eager andrew.eager@aes-pl.com.au Geoffrey Robertson ge@ffrey.com Nick Urbanik nicku@nicku.org This document Licensed under GPL—see section 12 BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document 2005 July Outline 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document Topic 113 Networking Services [24] Where we are up to 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective 1.113.1 Configure and manage inetd, xinetd, and related services [4] 1.113.2 Operate and perform basic configuration of sendmail [4] 1.113.3 Operate and perform basic configuration of Apache [4] 1.113.4 Properly manage the NFS, smb, and nmb daemons [4] 1.113.5 Setup and configure basic DNS services [4] 1.113.7 Set up secure shell (OpenSSH) [4] DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document Description of Objective 1.113.5 Setup and configure basic DNS services 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Candidate should be able to configure hostname lookups and troubleshoot problems with local caching-only name server. Requires an understanding of the domain registration and DNS translation process. Requires understanding key differences in configuration files for bind 4 and bind 8. /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document Key files, terms, and utilities include: 1.113.5 Setup and configure basic DNS services 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service /etc/hosts — file that maps host names ↔ IP addresses /etc/resolv.conf — configuration file used to determine which name server(s) to consult /etc/nsswitch.conf — tells system which order to consult various sources of naming information /etc/named.boot (v.4) or /etc/named.conf (v.8) — configuration file for named. named — the name server executable Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document DNS - Domain Name Service 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective The internet works with numbers not names. www.abc.gov.au is really 203.2.218.61 DNS namespace is made up of a tree of domain names. At the top is root (.) Below this is the Top Level Domain (TLD) Below the TLD is the Second Level Domain. The Second level domain is handled by whoever ’owns’ that domain Third & lower level domains are handled by the domain owner. DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document DNS - Domain Name Service 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective The internet works with numbers not names. www.abc.gov.au is really 203.2.218.61 DNS namespace is made up of a tree of domain names. At the top is root (.) Below this is the Top Level Domain (TLD) Below the TLD is the Second Level Domain. The Second level domain is handled by whoever ’owns’ that domain Third & lower level domains are handled by the domain owner. DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document DNS - Domain Name Service 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective The internet works with numbers not names. www.abc.gov.au is really 203.2.218.61 DNS namespace is made up of a tree of domain names. At the top is root (.) Below this is the Top Level Domain (TLD) Below the TLD is the Second Level Domain. The Second level domain is handled by whoever ’owns’ that domain Third & lower level domains are handled by the domain owner. DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document DNS - Domain Name Service 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective The internet works with numbers not names. www.abc.gov.au is really 203.2.218.61 DNS namespace is made up of a tree of domain names. At the top is root (.) Below this is the Top Level Domain (TLD) Below the TLD is the Second Level Domain. The Second level domain is handled by whoever ’owns’ that domain Third & lower level domains are handled by the domain owner. DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document DNS - Domain Name Service 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective The internet works with numbers not names. www.abc.gov.au is really 203.2.218.61 DNS namespace is made up of a tree of domain names. At the top is root (.) Below this is the Top Level Domain (TLD) Below the TLD is the Second Level Domain. The Second level domain is handled by whoever ’owns’ that domain Third & lower level domains are handled by the domain owner. DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document DNS - Domain Name Service 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective The internet works with numbers not names. www.abc.gov.au is really 203.2.218.61 DNS namespace is made up of a tree of domain names. At the top is root (.) Below this is the Top Level Domain (TLD) Below the TLD is the Second Level Domain. The Second level domain is handled by whoever ’owns’ that domain Third & lower level domains are handled by the domain owner. DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document DNS - Domain Name Service 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective The internet works with numbers not names. www.abc.gov.au is really 203.2.218.61 DNS namespace is made up of a tree of domain names. At the top is root (.) Below this is the Top Level Domain (TLD) Below the TLD is the Second Level Domain. The Second level domain is handled by whoever ’owns’ that domain Third & lower level domains are handled by the domain owner. DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document DNS - Domain Name Service 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective The internet works with numbers not names. www.abc.gov.au is really 203.2.218.61 DNS namespace is made up of a tree of domain names. At the top is root (.) Below this is the Top Level Domain (TLD) Below the TLD is the Second Level Domain. The Second level domain is handled by whoever ’owns’ that domain Third & lower level domains are handled by the domain owner. DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document DNS - Domain Name Service 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective Example: node1.office.my-domain.com ^ ^ ^ ^ | | | | | | | -- Top level domain | | -- Second level domain | - Subdomain -- Hostname Domain names are fully qualified (FQDN) when a name is specified all the way down to the hostname. DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document DNS - Domain Name Service 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective Example: node1.office.my-domain.com ^ ^ ^ ^ | | | | | | | -- Top level domain | | -- Second level domain | - Subdomain -- Hostname Domain names are fully qualified (FQDN) when a name is specified all the way down to the hostname. DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document DNS - Domain Name Service 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective Example: node1.office.my-domain.com ^ ^ ^ ^ | | | | | | | -- Top level domain | | -- Second level domain | - Subdomain -- Hostname Domain names are fully qualified (FQDN) when a name is specified all the way down to the hostname. DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document Resolving A Name 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service A name is resolved using the following steps: /etc/nsswitch.conf is checked to see what resolution method to use (eg: read /etc/hosts, use dns, use nis...) nsswitch says “use dns”: Read resolv.conf to see what name server to use Send request to name server and wait for response Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document nsswitch says “use hosts” Lookup /etc/hosts for a matching hostname Resolving A Name 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service A name is resolved using the following steps: /etc/nsswitch.conf is checked to see what resolution method to use (eg: read /etc/hosts, use dns, use nis...) nsswitch says “use dns”: Read resolv.conf to see what name server to use Send request to name server and wait for response Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document nsswitch says “use hosts” Lookup /etc/hosts for a matching hostname Resolving A Name 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service A name is resolved using the following steps: /etc/nsswitch.conf is checked to see what resolution method to use (eg: read /etc/hosts, use dns, use nis...) nsswitch says “use dns”: Read resolv.conf to see what name server to use Send request to name server and wait for response Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document nsswitch says “use hosts” Lookup /etc/hosts for a matching hostname Resolving A Name 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service A name is resolved using the following steps: /etc/nsswitch.conf is checked to see what resolution method to use (eg: read /etc/hosts, use dns, use nis...) nsswitch says “use dns”: Read resolv.conf to see what name server to use Send request to name server and wait for response Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document nsswitch says “use hosts” Lookup /etc/hosts for a matching hostname Resolving A Name 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service A name is resolved using the following steps: /etc/nsswitch.conf is checked to see what resolution method to use (eg: read /etc/hosts, use dns, use nis...) nsswitch says “use dns”: Read resolv.conf to see what name server to use Send request to name server and wait for response Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document nsswitch says “use hosts” Lookup /etc/hosts for a matching hostname Resolving A Name 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service A name is resolved using the following steps: /etc/nsswitch.conf is checked to see what resolution method to use (eg: read /etc/hosts, use dns, use nis...) nsswitch says “use dns”: Read resolv.conf to see what name server to use Send request to name server and wait for response Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document nsswitch says “use hosts” Lookup /etc/hosts for a matching hostname Resolving A Name 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service A name is resolved using the following steps: /etc/nsswitch.conf is checked to see what resolution method to use (eg: read /etc/hosts, use dns, use nis...) nsswitch says “use dns”: Read resolv.conf to see what name server to use Send request to name server and wait for response Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document nsswitch says “use hosts” Lookup /etc/hosts for a matching hostname Resolving A Name 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service A name is resolved using the following steps: /etc/nsswitch.conf is checked to see what resolution method to use (eg: read /etc/hosts, use dns, use nis...) nsswitch says “use dns”: Read resolv.conf to see what name server to use Send request to name server and wait for response Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document nsswitch says “use hosts” Lookup /etc/hosts for a matching hostname The nsswitch.conf file 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context This is a file that determines what mechanisms are used by the hostname library calls to resolve names. The file contains lines with an identifier followed by a list of methods to use for name lookups. An example: passwd: files nisplus nis shadow: files nisplus nis group: files nisplus nis hosts: db files dns Note that the other entries like passwd, shadow and group are used for other applications like login and have nothing to do with DNS. Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document The nsswitch.conf file 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context This is a file that determines what mechanisms are used by the hostname library calls to resolve names. The file contains lines with an identifier followed by a list of methods to use for name lookups. An example: passwd: files nisplus nis shadow: files nisplus nis group: files nisplus nis hosts: db files dns Note that the other entries like passwd, shadow and group are used for other applications like login and have nothing to do with DNS. Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document The nsswitch.conf file 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context This is a file that determines what mechanisms are used by the hostname library calls to resolve names. The file contains lines with an identifier followed by a list of methods to use for name lookups. An example: passwd: files nisplus nis shadow: files nisplus nis group: files nisplus nis hosts: db files dns Note that the other entries like passwd, shadow and group are used for other applications like login and have nothing to do with DNS. Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document The nsswitch.conf file 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context This is a file that determines what mechanisms are used by the hostname library calls to resolve names. The file contains lines with an identifier followed by a list of methods to use for name lookups. An example: passwd: files nisplus nis shadow: files nisplus nis group: files nisplus nis hosts: db files dns Note that the other entries like passwd, shadow and group are used for other applications like login and have nothing to do with DNS. Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document The nsswitch.conf file 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context This is a file that determines what mechanisms are used by the hostname library calls to resolve names. The file contains lines with an identifier followed by a list of methods to use for name lookups. An example: passwd: files nisplus nis shadow: files nisplus nis group: files nisplus nis hosts: db files dns Note that the other entries like passwd, shadow and group are used for other applications like login and have nothing to do with DNS. Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document The nsswitch.conf file In the hosts line, we see that any hostname to be looked up will be done in the following order: 1. Use local databases file (.db files in /var/db) 2. Read /etc/hosts 3. Search DNS 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name The Search options can be one of: nisplus (or nis+) nis (or yp) dns files db compat [NOTFOUND=return] — — — — — — — Consult NIS+ (Yellow Pages) Consult NIS Use a DNS server Use local files like /etc/hosts Use local database files Use NIS in compat mode Stop searching and return host notfound /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document The nsswitch.conf file In the hosts line, we see that any hostname to be looked up will be done in the following order: 1. Use local databases file (.db files in /var/db) 2. Read /etc/hosts 3. Search DNS 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name The Search options can be one of: nisplus (or nis+) nis (or yp) dns files db compat [NOTFOUND=return] — — — — — — — Consult NIS+ (Yellow Pages) Consult NIS Use a DNS server Use local files like /etc/hosts Use local database files Use NIS in compat mode Stop searching and return host notfound /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document The nsswitch.conf file In the hosts line, we see that any hostname to be looked up will be done in the following order: 1. Use local databases file (.db files in /var/db) 2. Read /etc/hosts 3. Search DNS 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name The Search options can be one of: nisplus (or nis+) nis (or yp) dns files db compat [NOTFOUND=return] — — — — — — — Consult NIS+ (Yellow Pages) Consult NIS Use a DNS server Use local files like /etc/hosts Use local database files Use NIS in compat mode Stop searching and return host notfound /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document An example nsswitch file: passwd: shadow: group hosts: db files nisplus nis nisplus db files nisplus nis db files nis dns 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name # Example - obey only what nisplus tells us... #services: nisplus [NOTFOUND=return] files #networks: nisplus [NOTFOUND=return] files #protocols: nisplus [NOTFOUND=return] files #rpc: nisplus [NOTFOUND=return] files #ethers: nisplus [NOTFOUND=return] files #netmasks: nisplus [NOTFOUND=return] files bootparams: nisplus [NOTFOUND=return] files ethers: netmasks: networks: protocols: rpc: services: netgroup: publickey: automount: aliases: files files files nis files nisplus files files nisplus files nisplus nisplus files nisplus files nisplus /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document The /etc/resolv.conf file 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective This file configures how the system uses DNS. An example: search aes nameserver 10.27.1.10 nameserver 10.27.1.254 The ’search’ line says what to append to a non-fully qualified name: eg: ping node10 → ping node10.aes The nameserver lines tell the hostname routines which dns server to send requests to. (If first lookup fails, use the second, third) DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document The /etc/resolv.conf file 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective This file configures how the system uses DNS. An example: search aes nameserver 10.27.1.10 nameserver 10.27.1.254 The ’search’ line says what to append to a non-fully qualified name: eg: ping node10 → ping node10.aes The nameserver lines tell the hostname routines which dns server to send requests to. (If first lookup fails, use the second, third) DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document The /etc/resolv.conf file 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective This file configures how the system uses DNS. An example: search aes nameserver 10.27.1.10 nameserver 10.27.1.254 The ’search’ line says what to append to a non-fully qualified name: eg: ping node10 → ping node10.aes The nameserver lines tell the hostname routines which dns server to send requests to. (If first lookup fails, use the second, third) DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document The /etc/resolv.conf file 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective This file configures how the system uses DNS. An example: search aes nameserver 10.27.1.10 nameserver 10.27.1.254 The ’search’ line says what to append to a non-fully qualified name: eg: ping node10 → ping node10.aes The nameserver lines tell the hostname routines which dns server to send requests to. (If first lookup fails, use the second, third) DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document BIND - Berkley Internet Name Domain 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Bind is just one implementation of a DNS. Bind is to DNS what Apache is to http. Bind is configured with: /etc/named.conf — For BIND V8 /etc/named.boot — For BIND V4 Know that there is a difference between V4 & V8. Know how to configure V8 but not V4. (Different syntax) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document BIND - Berkley Internet Name Domain 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Bind is just one implementation of a DNS. Bind is to DNS what Apache is to http. Bind is configured with: /etc/named.conf — For BIND V8 /etc/named.boot — For BIND V4 Know that there is a difference between V4 & V8. Know how to configure V8 but not V4. (Different syntax) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document BIND - Berkley Internet Name Domain 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Bind is just one implementation of a DNS. Bind is to DNS what Apache is to http. Bind is configured with: /etc/named.conf — For BIND V8 /etc/named.boot — For BIND V4 Know that there is a difference between V4 & V8. Know how to configure V8 but not V4. (Different syntax) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document BIND - Berkley Internet Name Domain 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Bind is just one implementation of a DNS. Bind is to DNS what Apache is to http. Bind is configured with: /etc/named.conf — For BIND V8 /etc/named.boot — For BIND V4 Know that there is a difference between V4 & V8. Know how to configure V8 but not V4. (Different syntax) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document BIND - Berkley Internet Name Domain 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Bind is just one implementation of a DNS. Bind is to DNS what Apache is to http. Bind is configured with: /etc/named.conf — For BIND V8 /etc/named.boot — For BIND V4 Know that there is a difference between V4 & V8. Know how to configure V8 but not V4. (Different syntax) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document BIND Configuration 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name The configuration file contains subsections as follows: Options → How named will operate logging → What/how named will log information Access Lists → Who can use named & what they can do Remote Servers → Characteristics of remote servers zones → Information about our defined domains /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document BIND Configuration 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name The configuration file contains subsections as follows: Options → How named will operate logging → What/how named will log information Access Lists → Who can use named & what they can do Remote Servers → Characteristics of remote servers zones → Information about our defined domains /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document BIND Configuration 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name The configuration file contains subsections as follows: Options → How named will operate logging → What/how named will log information Access Lists → Who can use named & what they can do Remote Servers → Characteristics of remote servers zones → Information about our defined domains /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document BIND Configuration 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name The configuration file contains subsections as follows: Options → How named will operate logging → What/how named will log information Access Lists → Who can use named & what they can do Remote Servers → Characteristics of remote servers zones → Information about our defined domains /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document BIND Configuration 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name The configuration file contains subsections as follows: Options → How named will operate logging → What/how named will log information Access Lists → Who can use named & what they can do Remote Servers → Characteristics of remote servers zones → Information about our defined domains /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document BIND Configuration 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name The configuration file contains subsections as follows: Options → How named will operate logging → What/how named will log information Access Lists → Who can use named & what they can do Remote Servers → Characteristics of remote servers zones → Information about our defined domains /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document An Example Config file: 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context options { directory "/var/named/"; forward only; forwarders { 203.2.75.132; 203.2.75.108; }; query-source address * port 53; listen-on { 10.27.1.10; 127.0.0.1; }; notify no; }; #### The root zone ### zone "." { type hint; file "named.ca"; }; Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document An Example Config file — continued #### A zone for localhost ### zone "0.0.127.in-addr.arpa" { type master; file "0.0.127.in-addr.arpa.zone"; }; zone "localhost" { type master; file "localhost.zone"; 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND }; ### A local domain ### zone "1.27.10.in-addr.arpa" { type master; file "1.27.10.in-addr.arpa.zone"; }; zone "aes" { type master; file "aes.zone"; BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document }; key "key" { algorithm hmac-md5; secret "JoqlFqtncqurkhMOrrbQLYRcxSYXoNROvNTZBqWJFumleNkzOvEvTAbqpbMV"; }; Zone files: 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Each zone uses a file for: Hostname to IP address translations (Forward lookups) IP to Hostname translatoins (Reverse lookups) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone The names can be anything, but usually: Forward file → domain .zone Reverse file → Net-IP .in-addr.arpa . . . where the Net-IP is the network part of the IP address. Example reverse zone Caching Only name server Testing DNS License Of This Document Zone files: 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Each zone uses a file for: Hostname to IP address translations (Forward lookups) IP to Hostname translatoins (Reverse lookups) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone The names can be anything, but usually: Forward file → domain .zone Reverse file → Net-IP .in-addr.arpa . . . where the Net-IP is the network part of the IP address. Example reverse zone Caching Only name server Testing DNS License Of This Document Zone files: 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Each zone uses a file for: Hostname to IP address translations (Forward lookups) IP to Hostname translatoins (Reverse lookups) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone The names can be anything, but usually: Forward file → domain .zone Reverse file → Net-IP .in-addr.arpa . . . where the Net-IP is the network part of the IP address. Example reverse zone Caching Only name server Testing DNS License Of This Document Zone files: 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Each zone uses a file for: Hostname to IP address translations (Forward lookups) IP to Hostname translatoins (Reverse lookups) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone The names can be anything, but usually: Forward file → domain .zone Reverse file → Net-IP .in-addr.arpa . . . where the Net-IP is the network part of the IP address. Example reverse zone Caching Only name server Testing DNS License Of This Document Zone files: 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Each zone uses a file for: Hostname to IP address translations (Forward lookups) IP to Hostname translatoins (Reverse lookups) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone The names can be anything, but usually: Forward file → domain .zone Reverse file → Net-IP .in-addr.arpa . . . where the Net-IP is the network part of the IP address. Example reverse zone Caching Only name server Testing DNS License Of This Document Zone files: 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Each zone uses a file for: Hostname to IP address translations (Forward lookups) IP to Hostname translatoins (Reverse lookups) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone The names can be anything, but usually: Forward file → domain .zone Reverse file → Net-IP .in-addr.arpa . . . where the Net-IP is the network part of the IP address. Example reverse zone Caching Only name server Testing DNS License Of This Document Zone files: 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Each zone uses a file for: Hostname to IP address translations (Forward lookups) IP to Hostname translatoins (Reverse lookups) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone The names can be anything, but usually: Forward file → domain .zone Reverse file → Net-IP .in-addr.arpa . . . where the Net-IP is the network part of the IP address. Example reverse zone Caching Only name server Testing DNS License Of This Document Zone files: 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Each zone uses a file for: Hostname to IP address translations (Forward lookups) IP to Hostname translatoins (Reverse lookups) Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone The names can be anything, but usually: Forward file → domain .zone Reverse file → Net-IP .in-addr.arpa . . . where the Net-IP is the network part of the IP address. Example reverse zone Caching Only name server Testing DNS License Of This Document Outline 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Zone Records: SOA record Marks the start of a zone, indicating which name server is the primary name server NS record Defines the name server for a zone or subdomain MX record Define mail servers for domain CNAME record Defines an alias for a hostname LOC record Defines the physical location of the server SRV record Defines what services are found where (eg ftp, http etc) A record Defines hostname to IP address translations (forward file) PTR record Defines IP address to hostname translations (reverse file) 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Zone Records: SOA record Marks the start of a zone, indicating which name server is the primary name server NS record Defines the name server for a zone or subdomain MX record Define mail servers for domain CNAME record Defines an alias for a hostname LOC record Defines the physical location of the server SRV record Defines what services are found where (eg ftp, http etc) A record Defines hostname to IP address translations (forward file) PTR record Defines IP address to hostname translations (reverse file) 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Zone Records: SOA record Marks the start of a zone, indicating which name server is the primary name server NS record Defines the name server for a zone or subdomain MX record Define mail servers for domain CNAME record Defines an alias for a hostname LOC record Defines the physical location of the server SRV record Defines what services are found where (eg ftp, http etc) A record Defines hostname to IP address translations (forward file) PTR record Defines IP address to hostname translations (reverse file) 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Zone Records: SOA record Marks the start of a zone, indicating which name server is the primary name server NS record Defines the name server for a zone or subdomain MX record Define mail servers for domain CNAME record Defines an alias for a hostname LOC record Defines the physical location of the server SRV record Defines what services are found where (eg ftp, http etc) A record Defines hostname to IP address translations (forward file) PTR record Defines IP address to hostname translations (reverse file) 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Zone Records: SOA record Marks the start of a zone, indicating which name server is the primary name server NS record Defines the name server for a zone or subdomain MX record Define mail servers for domain CNAME record Defines an alias for a hostname LOC record Defines the physical location of the server SRV record Defines what services are found where (eg ftp, http etc) A record Defines hostname to IP address translations (forward file) PTR record Defines IP address to hostname translations (reverse file) 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Zone Records: SOA record Marks the start of a zone, indicating which name server is the primary name server NS record Defines the name server for a zone or subdomain MX record Define mail servers for domain CNAME record Defines an alias for a hostname LOC record Defines the physical location of the server SRV record Defines what services are found where (eg ftp, http etc) A record Defines hostname to IP address translations (forward file) PTR record Defines IP address to hostname translations (reverse file) 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Zone Records: SOA record Marks the start of a zone, indicating which name server is the primary name server NS record Defines the name server for a zone or subdomain MX record Define mail servers for domain CNAME record Defines an alias for a hostname LOC record Defines the physical location of the server SRV record Defines what services are found where (eg ftp, http etc) A record Defines hostname to IP address translations (forward file) PTR record Defines IP address to hostname translations (reverse file) 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Zone Records: SOA record Marks the start of a zone, indicating which name server is the primary name server NS record Defines the name server for a zone or subdomain MX record Define mail servers for domain CNAME record Defines an alias for a hostname LOC record Defines the physical location of the server SRV record Defines what services are found where (eg ftp, http etc) A record Defines hostname to IP address translations (forward file) PTR record Defines IP address to hostname translations (reverse file) 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Zone Records: SOA record Marks the start of a zone, indicating which name server is the primary name server NS record Defines the name server for a zone or subdomain MX record Define mail servers for domain CNAME record Defines an alias for a hostname LOC record Defines the physical location of the server SRV record Defines what services are found where (eg ftp, http etc) A record Defines hostname to IP address translations (forward file) PTR record Defines IP address to hostname translations (reverse file) 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Outline 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Example Forward file /var/named/aes.zone @ IN SOA node10.aes. root.localhost ( 2 ; serial 28800 ; refresh 7200 ; retry 604800 ; expire 86400 ; ttl ) node10.aes. 10 10 10 10 10 10 mail mail mail mail mail mail 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND @ node5 node6 node4 node2 node10 gw node10 node2 node4 node5 node6 cds gw ns mail node-4 IN IN IN IN IN IN IN IN IN IN IN IN IN IN IN IN IN NS MX MX MX MX MX MX A A A A A A A CNAME CNAME CNAME BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document 10.27.1.10 10.27.1.2 10.27.1.4 10.27.1.5 10.27.1.6 10.27.1.99 10.27.1.254 node10 node10 node4 Outline 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Example reverse file /var/named/1.27.10.in-addr.arpa.zone 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name @ IN SOA @ root.localhost ( 2 ; serial 28800 ; refresh 7200 ; retry 604800 ; expire 86400 ; ttk ) /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files @ 2 4 5 6 10 99 254 IN IN IN IN IN IN IN IN NS PTR PTR PTR PTR PTR PTR PTR ns.aes. node2.aes. node4.aes. node5.aes. node6.aes. node10.aes. cds.aes. gw.aes. Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS License Of This Document Configuring a Caching only Nameserver A caching only nameserver is simple to setup. The first time a name is needed, a normal lookup occurs (Authorative) The next time that name is needed, it is returned from cache (Non-authorative) Under /etc/named.conf in the options section, just make sure you have the following directives set: options { directory "/var/named/"; forward only; forwarders { First DNS to query ; Second DNS to query ; }; listen-on { Your local IP address ; 127.0.0.1; }; Leave the root zone (.) and localhost entries as they are. 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document Configuring a Caching only Nameserver A caching only nameserver is simple to setup. The first time a name is needed, a normal lookup occurs (Authorative) The next time that name is needed, it is returned from cache (Non-authorative) Under /etc/named.conf in the options section, just make sure you have the following directives set: options { directory "/var/named/"; forward only; forwarders { First DNS to query ; Second DNS to query ; }; listen-on { Your local IP address ; 127.0.0.1; }; Leave the root zone (.) and localhost entries as they are. 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document Configuring a Caching only Nameserver A caching only nameserver is simple to setup. The first time a name is needed, a normal lookup occurs (Authorative) The next time that name is needed, it is returned from cache (Non-authorative) Under /etc/named.conf in the options section, just make sure you have the following directives set: options { directory "/var/named/"; forward only; forwarders { First DNS to query ; Second DNS to query ; }; listen-on { Your local IP address ; 127.0.0.1; }; Leave the root zone (.) and localhost entries as they are. 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document Configuring a Caching only Nameserver A caching only nameserver is simple to setup. The first time a name is needed, a normal lookup occurs (Authorative) The next time that name is needed, it is returned from cache (Non-authorative) Under /etc/named.conf in the options section, just make sure you have the following directives set: options { directory "/var/named/"; forward only; forwarders { First DNS to query ; Second DNS to query ; }; listen-on { Your local IP address ; 127.0.0.1; }; Leave the root zone (.) and localhost entries as they are. 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document Testing DNS 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name To test DNS, use one of the following tools: nslookup (deprecated) dig host /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host To use in their simplest form, just add the hostname you wish to query as the first option to the command: $ nslookup node16.c223 ← $ dig node16.c223 ← $ host node16.c223 ← License Of This Document Testing DNS 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name To test DNS, use one of the following tools: nslookup (deprecated) dig host /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host To use in their simplest form, just add the hostname you wish to query as the first option to the command: $ nslookup node16.c223 ← $ dig node16.c223 ← $ host node16.c223 ← License Of This Document Testing DNS 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name To test DNS, use one of the following tools: nslookup (deprecated) dig host /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host To use in their simplest form, just add the hostname you wish to query as the first option to the command: $ nslookup node16.c223 ← $ dig node16.c223 ← $ host node16.c223 ← License Of This Document Testing DNS 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name To test DNS, use one of the following tools: nslookup (deprecated) dig host /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host To use in their simplest form, just add the hostname you wish to query as the first option to the command: $ nslookup node16.c223 ← $ dig node16.c223 ← $ host node16.c223 ← License Of This Document Testing DNS 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name To test DNS, use one of the following tools: nslookup (deprecated) dig host /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host To use in their simplest form, just add the hostname you wish to query as the first option to the command: $ nslookup node16.c223 ← $ dig node16.c223 ← $ host node16.c223 ← License Of This Document Testing DNS 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name To test DNS, use one of the following tools: nslookup (deprecated) dig host /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host To use in their simplest form, just add the hostname you wish to query as the first option to the command: $ nslookup node16.c223 ← $ dig node16.c223 ← $ host node16.c223 ← License Of This Document Outline 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document nslookup 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Usage: nslookup [option] host-to-find [-name-server] Example: $ nslookup node2.aes -10.27.1.10 ← Note: nslookup is deprecated and may be removed from future releases. Consider using the ‘dig’ or ‘host’ programs instead. Run nslookup with the -sil[ent] option to prevent this message from appearing. Server: Address: 10.27.1.10 10.27.1.10#53 Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host Name: node2.aes Address: 10.27.1.2 License Of This Document nslookup 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Usage: nslookup [option] host-to-find [-name-server] Example: $ nslookup node2.aes -10.27.1.10 ← Note: nslookup is deprecated and may be removed from future releases. Consider using the ‘dig’ or ‘host’ programs instead. Run nslookup with the -sil[ent] option to prevent this message from appearing. Server: Address: 10.27.1.10 10.27.1.10#53 Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host Name: node2.aes Address: 10.27.1.2 License Of This Document nslookup 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Usage: nslookup [option] host-to-find [-name-server] Example: $ nslookup node2.aes -10.27.1.10 ← Note: nslookup is deprecated and may be removed from future releases. Consider using the ‘dig’ or ‘host’ programs instead. Run nslookup with the -sil[ent] option to prevent this message from appearing. Server: Address: 10.27.1.10 10.27.1.10#53 Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host Name: node2.aes Address: 10.27.1.2 License Of This Document Outline 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document dig Usage: dig [@name-server] host-to-find [query-type] Example: $ dig @10.27.1.10 node2.aes ← 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name ; «» DiG 9.2.0 «» @10.27.1.10 node2.aes ;; global options: printcmd /etc/nsswitch.conf ;; Got answer: /etc/resolv.conf ;; -»HEADER«- opcode: QUERY, status: NOERROR, id: 43860 BIND ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1 BIND configuration ;; QUESTION SECTION: ;node2.aes. ;; ANSWER SECTION: node2.aes. ;; AUTHORITY SECTION: aes. ;; ADDITIONAL SECTION: node10.aes. ;; ;; ;; ;; IN A Zone Files Caching Only name server 86400 IN A 10.27.1.2 Testing DNS nslookup dig 86400 IN NS node10.aes. host License Of This Document 86400 IN A 10.27.1.10 Query time: 5 msec SERVER: 10.27.1.10#53(10.27.1.10) WHEN: Mon Sep 2 13:48:38 2002 MSG SIZE rcvd: 80 dig Usage: dig [@name-server] host-to-find [query-type] Example: $ dig @10.27.1.10 node2.aes ← 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name ; «» DiG 9.2.0 «» @10.27.1.10 node2.aes ;; global options: printcmd /etc/nsswitch.conf ;; Got answer: /etc/resolv.conf ;; -»HEADER«- opcode: QUERY, status: NOERROR, id: 43860 BIND ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1 BIND configuration ;; QUESTION SECTION: ;node2.aes. ;; ANSWER SECTION: node2.aes. ;; AUTHORITY SECTION: aes. ;; ADDITIONAL SECTION: node10.aes. ;; ;; ;; ;; IN A Zone Files Caching Only name server 86400 IN A 10.27.1.2 Testing DNS nslookup dig 86400 IN NS node10.aes. host License Of This Document 86400 IN A 10.27.1.10 Query time: 5 msec SERVER: 10.27.1.10#53(10.27.1.10) WHEN: Mon Sep 2 13:48:38 2002 MSG SIZE rcvd: 80 dig Usage: dig [@name-server] host-to-find [query-type] Example: $ dig @10.27.1.10 node2.aes ← 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name ; «» DiG 9.2.0 «» @10.27.1.10 node2.aes ;; global options: printcmd /etc/nsswitch.conf ;; Got answer: /etc/resolv.conf ;; -»HEADER«- opcode: QUERY, status: NOERROR, id: 43860 BIND ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1 BIND configuration ;; QUESTION SECTION: ;node2.aes. ;; ANSWER SECTION: node2.aes. ;; AUTHORITY SECTION: aes. ;; ADDITIONAL SECTION: node10.aes. ;; ;; ;; ;; IN A Zone Files Caching Only name server 86400 IN A 10.27.1.2 Testing DNS nslookup dig 86400 IN NS node10.aes. host License Of This Document 86400 IN A 10.27.1.10 Query time: 5 msec SERVER: 10.27.1.10#53(10.27.1.10) WHEN: Mon Sep 2 13:48:38 2002 MSG SIZE rcvd: 80 Outline 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document host 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Usage: host [option] host-to-find [name-server] Example: $ host node2.aes ← node2.aes has address 10.27.1.2 /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document host 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Usage: host [option] host-to-find [name-server] Example: $ host node2.aes ← node2.aes has address 10.27.1.2 /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document host 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Usage: host [option] host-to-find [name-server] Example: $ host node2.aes ← node2.aes has address 10.27.1.2 /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Exercise: 1. Install bind on your machine: $ sudo rpm -Uvh bind-9*.rpm ← 2. Configure a Caching only nameserver on your machine. (Make all queries forward to 192.168.223.254) 3. Make changes to resolv.conf & nsswitch.conf as required (Default domain to use is c223) 4. Start the named. $ sudo service named start ← 5. Test it out with the host node16.c223 using: nslookup dig host 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host 6. Test again this time with the host box16 7. (For those who want a DNS challenge) 7.1 Setup a set of zones for the .c223 domain. 7.2 Insert the new zone into the main configuration file 7.3 Restart the named and test it. License Of This Document Exercise: 1. Install bind on your machine: $ sudo rpm -Uvh bind-9*.rpm ← 2. Configure a Caching only nameserver on your machine. (Make all queries forward to 192.168.223.254) 3. Make changes to resolv.conf & nsswitch.conf as required (Default domain to use is c223) 4. Start the named. $ sudo service named start ← 5. Test it out with the host node16.c223 using: nslookup dig host 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host 6. Test again this time with the host box16 7. (For those who want a DNS challenge) 7.1 Setup a set of zones for the .c223 domain. 7.2 Insert the new zone into the main configuration file 7.3 Restart the named and test it. License Of This Document Exercise: 1. Install bind on your machine: $ sudo rpm -Uvh bind-9*.rpm ← 2. Configure a Caching only nameserver on your machine. (Make all queries forward to 192.168.223.254) 3. Make changes to resolv.conf & nsswitch.conf as required (Default domain to use is c223) 4. Start the named. $ sudo service named start ← 5. Test it out with the host node16.c223 using: nslookup dig host 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host 6. Test again this time with the host box16 7. (For those who want a DNS challenge) 7.1 Setup a set of zones for the .c223 domain. 7.2 Insert the new zone into the main configuration file 7.3 Restart the named and test it. License Of This Document Exercise: 1. Install bind on your machine: $ sudo rpm -Uvh bind-9*.rpm ← 2. Configure a Caching only nameserver on your machine. (Make all queries forward to 192.168.223.254) 3. Make changes to resolv.conf & nsswitch.conf as required (Default domain to use is c223) 4. Start the named. $ sudo service named start ← 5. Test it out with the host node16.c223 using: nslookup dig host 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host 6. Test again this time with the host box16 7. (For those who want a DNS challenge) 7.1 Setup a set of zones for the .c223 domain. 7.2 Insert the new zone into the main configuration file 7.3 Restart the named and test it. License Of This Document Exercise: 1. Install bind on your machine: $ sudo rpm -Uvh bind-9*.rpm ← 2. Configure a Caching only nameserver on your machine. (Make all queries forward to 192.168.223.254) 3. Make changes to resolv.conf & nsswitch.conf as required (Default domain to use is c223) 4. Start the named. $ sudo service named start ← 5. Test it out with the host node16.c223 using: nslookup dig host 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host 6. Test again this time with the host box16 7. (For those who want a DNS challenge) 7.1 Setup a set of zones for the .c223 domain. 7.2 Insert the new zone into the main configuration file 7.3 Restart the named and test it. License Of This Document Exercise: 1. Install bind on your machine: $ sudo rpm -Uvh bind-9*.rpm ← 2. Configure a Caching only nameserver on your machine. (Make all queries forward to 192.168.223.254) 3. Make changes to resolv.conf & nsswitch.conf as required (Default domain to use is c223) 4. Start the named. $ sudo service named start ← 5. Test it out with the host node16.c223 using: nslookup dig host 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host 6. Test again this time with the host box16 7. (For those who want a DNS challenge) 7.1 Setup a set of zones for the .c223 domain. 7.2 Insert the new zone into the main configuration file 7.3 Restart the named and test it. License Of This Document Exercise: 1. Install bind on your machine: $ sudo rpm -Uvh bind-9*.rpm ← 2. Configure a Caching only nameserver on your machine. (Make all queries forward to 192.168.223.254) 3. Make changes to resolv.conf & nsswitch.conf as required (Default domain to use is c223) 4. Start the named. $ sudo service named start ← 5. Test it out with the host node16.c223 using: nslookup dig host 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host 6. Test again this time with the host box16 7. (For those who want a DNS challenge) 7.1 Setup a set of zones for the .c223 domain. 7.2 Insert the new zone into the main configuration file 7.3 Restart the named and test it. License Of This Document DNS Name Lookup Procedure 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective ' & ? What is IP addr for www.abc.com?   £ - What is IP for www.abc.com? ¡ ¢ $£ ¢ % Don’t know, but here is the IP for  the .com Nameserver. Go ask them   ¡ - DNS — Domain Name Service . (root) DNS Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration    ?  LOCAL DNS IP addr is   £ - What is IP for www.abc.com? ¡ ¢ £ ¢ Don’t know, but here is the IP for the abc.com Nameserver. Go ask them    ¡ - .com DNS Zone Files Caching Only name server Testing DNS nslookup dig host  1.2.3.4  £   - What is IP for www.abc.com? ¢ £  ¡ The IP for www.abc.com  ¢ is 1.2.3.4 ¡ abc.com DNS License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document Topics Covered 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Context Objective DNS — Domain Name Service Resolving a Name /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Zone Records Example forward zone Example reverse zone Caching Only name server Testing DNS nslookup dig host License Of This Document /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS nslookup dig host License Of This Document License Of This Document 1.113.5 Setup and configure basic DNS services Weight 4 Andrew Eager Context Objective DNS — Domain Name Service Resolving a Name Copyright c 2005, 2003 Andrew Eager , Geoffrey Robertson and Nick Urbanik . Permission is granted to make and distribute verbatim copies or modified versions of this document provided that this copyright notice and this permission notice are preserved on all copies under the terms of the GNU General Public License as published by the Free Software Foundation—either version 2 of the License or (at your option) any later version. /etc/nsswitch.conf /etc/resolv.conf BIND BIND configuration Zone Files Caching Only name server Testing DNS License Of This Document