Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide - Manual (Page 189)

Enabling and disabling IPv6 router advertisements
If IPv6 unicast routing is enabled on an Ethernet interface, by default, this interface sends IPv6 router
advertisement messages. However, by default, non-LAN interface types, for example, tunnel interfaces,
do not send router advertisement messages.
To disable the sending of router advertisement messages on an Ethernet interface, enter commands
such as the following.
device(config)#interface ethernet 3/1
device(config-if-e1000-3/1)#ipv6 nd suppress-ra
To enable the sending of router advertisement messages on a tunnel interface, enter commands such
as the following.
device(config)#interface tunnel 1
device(config-tnif-1)#no ipv6 nd suppress-ra
Syntax: [no] ipv6 nd suppress-ra
IPv6 router advertisement preference support
IPv6 router advertisement (RA) preference enables IPv6 RA messages to communicate default router
preferences from IPv6 routers to IPv6 hosts in network topologies where the host has multiple routers
on its Default Router List. This improves the ability of the IPv6 hosts to select an appropriate router for
an off-link destination.
Configuring IPv6 RA preference
Configuring IPv6 RA preference
To configure IPv6 RA preference for the IPv6 router, use the ipv6 nd router-preference in the
interface configuration mode.
The following example shows the router preference configured for interface 2/3
with the preference value "low".
device(config)#interface ethernet 2/3
device(config-if-eth2/3)#ipv6 nd router-preference low
Configuring reachable time for remote IPv6 nodes
You can configure the duration (in seconds) that a router considers a remote IPv6 node reachable. By
default, a router interface uses the value of 30 seconds.
The router advertisement messages sent by a router interface include the amount of time specified by
the ipv6 nd reachable-time command so that nodes on a link use the same reachable time duration.
By default, the messages include a default value of 0.
Brocade does not recommend configuring a short reachable time duration, because a short duration
causes the IPv6 network devices to process the information at a greater frequency.
For example, to configure the reachable time of 40 seconds for Ethernet interface 3/1, enter the
following commands.
device(config)#interface ethernet 3/1
device(config-if-e1000-3/1)#ipv6 nd reachable-time 40
Enabling and disabling IPv6 router advertisements
FastIron Ethernet Switch Layer 3 Routing Configuration Guide 189
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