Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 600)

Only the master answers an ARP request for the virtual router IP address. Any backup router that
receives this request forwards the request to the master.
VRRP control packets
VRRP: VRRP control packets are IP protocol type 112 (reserved for VRRP), and are sent to VRRP
multicast address 224.0.0.18.
VRRP-E: control packets are UDP packets destined to port 8888, and are sent to the all-router
multicast address 224.0.0.2.
Source MAC in VRRP control packets
VRRP: The virtual MAC address is the source.
VRRP-E: The physical MAC address is the source.
Track ports and track priority with VRRP and VRRP-E
A track port allows you to monitor the state of the interfaces on the other end of a the route path. A
track port also allows the virtual router to lower its priority if the exit path interface goes down, allowing
another virtual router in the same VRRP (or VRRP-E) group to take over. Consider the following
conditions and limitations for track ports:
• Track priorities must be lower than VRRP/VRRP-E priorities.
• The dynamic change of router priority can trigger mastership switchover if preemption is enabled.
However, if the router is an owner (applicable only for VRRP), the mastership switchover will not
occur.
• Maximum number of interfaces that can be tracked for a virtual router is 16.
• Port tracking is allowed for physical interfaces and port-channels.
Short-path forwarding (VRRP-E only)
VRRP-E is enhanced with the VRRP-E extension for Server Virtualization feature so that Brocade
devices attempt to bypass the VRRP-E master router and directly forward packets to their destination
through interfaces on the backup router. This is called short-path forwarding. A backup router
participates in a VRRP-E session only when short-path-forwarding is enabled.
VRRP-E active-active load-balancing is achieved with the ingress RBridge, by hashing either the L2-7
header information (Brocade VDX 8770) or the destination MAC address (Brocade VDX 67xx) to
determine the path. All nodes in the VCS are aware of all VRRP-E sessions and the participating
RBridges in each session.
If short-path forwarding is enabled, traffic travels through the short-path forwarding path (dashed line
in the figure in
Packet routing with short-path forwarding (VRRP-E only) on page 600) to reach the
client.
Packet routing with short-path forwarding (VRRP-E only)
If you enable short-path forwarding for VRRP-E, all packets sent by the local subnet of the virtual IP
address are routed to the WAN instead of being switched to the master router.
In the figure below, the virtual servers are dynamically moved between Host Server 1 and Host Server
2.
VRRP control packets
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