Administrator Guide

Figure 62. NDP Router Redirect
IPv6 Neighbor Discovery of MTU Packets
You can set the MTU advertised through the RA packets to incoming routers, without altering the actual MTU setting on the interface.
The ipv6 nd mtu command sets the value advertised to routers. It does not set the actual MTU rate. For example, if you set ipv6 nd
mtu to 1280, the interface still passes 1500-byte packets, if that is what is set with the mtu command.
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.
DellEMC(conf-if-te-1/1/1)#ipv6 nd dns-server ?
X:X:X:X::X Recursive DNS Server's (RDNSS) IPv6 address
DellEMC(conf-if-te-1/1/1)#ipv6 nd dns-server 1000::1 ?
<0-4294967295> Max lifetime (sec) which RDNSS address may be used for name resolution
infinite Infinite lifetime (sec) which RDNSS address may be used for name
resolution
DellEMC(conf-if-te-1/1/1)#ipv6 nd dns-server 1000::1 1
IPv6 Routing
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