Brocade BigIron RX Series Configuration Guide - Manual (Page 663)

BigIron RX Series Configuration Guide 585
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MCT for VRRP or VRRP-E
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• The VRRP-E virtual MAC address must be synced and learned on the ICL ports on backup
routers through the ICL.
• The IPv4 multicast traffic must be supported on the ICLs:
- For the VRRP or VRRP-E master router - Hello packets are broadcast to all the VLAN
member ports including ICL ports. Normal VLAN FIDs are used for broadcasting.
- For the VRRP or VRRP-E backup routers - Hello packets received from the ICL ports are not
flooded back to the ICL ports, but flooded to other non-ICL ports.
• The MCT switches must have complete routing information using the static routes for Layer 3
forwarding.
• For the MCT switches configured with VRRP or VRRP-E, the track-port feature can be enabled
to track the link status of core switches so that VRRP or VRRP-E failover can be triggered when
both the links to the core switches are down.
• In a short-path forwarding situation, Open Shortest Path First (OSPF) with a higher cost must
be allowed on the ICL to avoid a routing "black hole" when both the links to the core switches
are down.
NOTE
Brocade recommends disabling the Internet Control Message Protocol (ICMP) redirect globally to
avoid unintended CPU forwarding of traffic when VRRP or VRRP-E is configured.
Enabling VRRP-E short-path forwarding behavior
You can use the short-path-forwarding command under the VRRP-E VRID configuration level to
enable the short-path forwarding behavior on the VRRP-E backup router. Enabling short-path
forwarding behavior on the backup router routes the traffic to the destination router instead of
switching the traffic to the VRRP-E master router.
The revert-priority option in the short-path-forwarding command reverts the short-path forwarding
behavior to the standard VRRP-E forwarding behavior based on the current priority value of VRRP-E.
If the revert-priority option is not enabled, the default behavior remains the same.
The track-port command monitors the status of the outgoing port on the backup router. To enable
short-path forwarding behavior on the backup router, enter a command such as the following.
BigIron RX(config-if-e1000-vrid-2)# short-path-forwarding revert-priority 60
Syntax: [no] short-path-forwarding [revert-priority <value>]
The <value> variable specifies the threshold priority value to determine if the short-path forwarding
behavior is effective. If one or more ports tracked by the track-port command go down, the current
priority of VRRP-E is lowered by a specific amount configured in the track-port command for each
port that goes down.
When the current priority is lower than the threshold, the short-path forwarding behavior is
temporally suspended and reverts to the standard VRRP-E forwarding behavior.
The reverting behavior is temporary. If one or more of the already down ports tracked by the
track-port command becomes active, it is possible that the current priority of VRRP-E will be higher
than the threshold, and the short-path forwarding behavior will be resumed.