CLI Reference Guide

Chapter 28 | IP Interface Commands
IPv6 Interface
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preferred-lifetime - The amount of time that the specified IPv6 prefix is
advertised as being preferred. The preferred lifetime is counted down in
real time. (Range: 0-4294967295 seconds)
no-autoconfig - Indicates to hosts on the local link that the specified prefix
cannot be used for IPv6 autoconfiguration.
off-link - Indicates that the specified prefix is assigned to the link. Nodes
sending traffic to addresses that contain the prefix consider the destination
to be locally reachable on the link.
Default Setting
valid-lifetime 2592000 seconds
preferred-lifetime 2592000 seconds
no-autoconfig Disabled
off-link Disabled
Command Mode
Interface Configuration (VLAN)
Command Usage
◆ Prefixes configured as addresses on an interface using the ipv6 address
command are advertised in router advertisements. If prefixes are configured for
advertisement using the ipv6 nd prefix command, then only these prefixes are
advertised.
◆ The preferred lifetime and valid lifetime are counted down in real time. After
the preferred lifetime expires, no new connections are made using this prefix.
When the valid lifetime expires, this prefix will no longer be advertised.
◆ All prefixes are inserted in the routing table as Connected (i.e., on-line), unless
specified with the off-link option. If the off-link option is specified, and the
prefix is already present in the routing table as a Connected prefix, it will be
removed.
◆ Do not include the link-local prefix in the list of advertised prefixes.
Example
The following configures a network prefix with a valid lifetime of 1000 seconds, and
a preferred lifetime of 900 seconds:
Console(config)#interface vlan 1
Console(config)#ipv6 nd prefix 2011:0DBF::/35 1000 900
Console(config)#
ipv6 nd ra interval This command configures the interval between the transmission of IPv6 router
advertisements on an interface. Use the no form to restore the default interval.