Administrator Guide
Configuring the IPv6 Recursive DNS Server
You can configure up to four Recursive DNS Server (RDNSS) addresses to be distributed via IPv6 router
advertisements to an IPv6 device, using the ipv6 nd dns-server ipv6-RDNSS-address {lifetime |
infinite} command in INTERFACE CONFIG mode.
The lifetime parameter configures the amount of time the IPv6 host can use the IPv6 RDNSS address for
name resolution. The lifetime range is 0 to 4294967295 seconds. When the maximum lifetime value,
4294967295, or the infinite keyword is specified, the lifetime to use the RDNSS address does not expire.
A value of
0 indicates to the host that the RDNSS address should not be used. You must specify a lifetime
using the lifetime or infinite parameter.
The DNS server address does not allow the following:
• link local addresses
• loopback addresses
• prefix addresses
• multicast addresses
• invalid host addresses
If you specify this information in the IPv6 RDNSS configuration, a DNS error is displayed.
Example for Configuring an IPv6 Recursive DNS Server
The following example configures a RDNNS server with an IPv6 address of 1000::1 and a lifetime of 1
second.
Displaying IPv6 RDNSS Information
To display IPv6 interface information, including IPv6 RDNSS information, use the show ipv6 interface
command in EXEC or EXEC Privilege mode.
Examples of Displaying IPv6 RDNSS Information
The following example displays IPv6 RDNSS information. The output in the last 3 lines indicates that the IPv6
RDNSS was correctly configured on interface te 1/1.
To display IPv6 RDNSS information, use the show configuration command in INTERFACE CONFIG mode.
The following example uses the show configuration command to display IPv6 RDNSS information.
IPv6 Routing 479