BigIron RX Series Configuration Guide 107153-1001986-01Configuring IPv6 Domain Name Server (DNS) resolver 43Configuring IPv6 Domain Name Server (DNS) resolverThe Domain Name Server (DNS) resolver feature lets you use a host name to perform Telnet, ping,and traceroute commands. You can also define a DNS domain on a Brocade device and therebyrecognize all hosts within that domain. After you define a domain name, the Brocade deviceautomatically appends the appropriate domain to the host and forwards it to the domain nameserver.For example, if the domain “newyork.com” is defined on a Brocade device, and you want to initiatea ping to host “NYC01” on that domain, you need to reference only the host name in the commandinstead of the host name and its domain name. For example, you could enter either of the followingcommands to initiate the ping.BigIron RX# ping nyc01BigIron RX# ping nyc01.newyork.comDefining a DNS entryYou can define up to four DNS servers for each DNS entry. The first entry serves as the primarydefault address. If a query to the primary address fails to be resolved after three attempts, the nextgateway address is queried (also up to three times). This process continues for each definedgateway address until the query is resolved. The order in which the default gateway addresses arepolled is the same as the order in which you enter them.Suppose you want to define the domain name of newyork.com on a Brocade device and thendefine four possible default DNS gateway addresses. To do so using IPv4 addressing, you wouldenter the following commands.BigIron RX(config)# ip dns domain-name newyork.comBigIron RX(config)# ip dns server-address 209.157.22.199 205.96.7.15 208.95.7.25201.98.7.15Syntax: ip dns server-address <ip-addr> [<ip-addr>] [<ip-addr>] [<ip-addr>]In this example, the first IP address in the ip dns server-address... command becomes the primarygateway address and all others are secondary addresses. Because IP address 201.98.7.15 is thelast address listed, it is also the last address consulted to resolve a query.Defining an IPv6 DNS entryIPv6 defines new DNS record types to resolve queries for domain names to IPv6 addresses, as wellas IPv6 addresses to domain names. Brocade devices running IPv6 software support AAAA DNSrecords, which are defined in RFC 1886.AAAA DNS records are analogous to the A DNS records used with IPv4. They store a complete IPv6address in each record. AAAA records have a type value of 28.To establish an IPv6 DNS entry for the device, enter the following command.BigIron RX(config)# ipv6 dns domain-name companynet.comSyntax: [no] ipv6 dns domain-name <domain name>To define an IPv6 DNS server address, enter the following command.BigIron RX(config)# ipv6 dns server-address 200::1Syntax: [no] ipv6 dns server-address <ipv6-addr> [<ipv6-addr>] [>] [<ipv6-addr>]
