Conguring IPv6 RA preference
Conguring IPv6 RA preference
If IPv6 unicast routing is enabled on an Ethernet interface, by default, this interface sends IPv6 router advertisement messages. The IPv6
router sets the preference eld based on the congured value on IPv6 RA and sends it periodically to the IPv6 host or as a response to
the router solicitations.
To congure IPv6 RA preference for the IPv6 router, use the ipv6 nd router-preference in the interface conguration mode.
The following example shows the router preference congured for interface 1/2/3 with the preference value "low".
device(config)#interface ethernet 1/2/3
device(config-if-e1000-1/2/3)#ipv6 nd router-preference low
Conguring reachable time for remote IPv6 nodes
You can congure 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 specied 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 conguring 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 congure the reachable time of 40 seconds for Ethernet interface 1/3/1, enter the following commands.
device(config)#interface ethernet 1/3/1
device(config-if-e1000-1/3/1)#ipv6 nd reachable-time 40
Syntax: [no] ipv6 nd reachable-time seconds
For the seconds variable, specify a number from 0 through 3600 seconds. To restore the default time, use the no form of this
command.
NOTE
The actual reachable time will be from 0.5 to 1.5 times the congured or default
value.
IPv6 MTU
The IPv6 maximum transmission unit (MTU) is the maximum length of an IPv6 packet that can be transmitted on a particular interface. If
an IPv6 packet is longer than an MTU, the host that originated the packet fragments the packet and transmits its contents in multiple
packets that are shorter than the
congured MTU.
By default, in non-jumbo mode, the default and maximum Ethernet MTU size is 1500 bytes. When jumbo mode is enabled, the default
Ethernet MTU size is 9216. The maximum Ethernet MTU size is 10200 for Brocade ICX 6610 devices, 10178 for Brocade ICX 6450
devices, and 10218 for other devices.
Conguration notes and feature limitations for IPv6 MTU
• The IPv6 MTU functionality is applicable to VEs and physical IP interfaces. It applies to trac routed between networks.
• For ICX 7250, ICX 7450, and ICX 7750 devices, the IPv4 and IPv6 MTU values are the same. Modifying one also changes
the value of the other.
IPv6 MTU
FastIron Ethernet Switch Layer 3 Routing
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