Brocade Communications Systems FastIron SX 1600, Configuration Manual, Page: 536 / 593

VRRP-E slow start timer
In a VRRP-E configuration, if a Master router goes down, the Backup router with the highest priority takes over after expiration of the
dead interval. When the original Master router comes back up again, it takes over from the Backup router (which became the Master
router when the original Master router went down). By default, this transition from Backup back to Master takes place immediately.
However, you can configure the VRRP-E slow start timer feature, which causes a specified amount of time to elapse between the time
the Master is restored and when it takes over from the Backup. This interval allows time for OSPF convergence when the Master is
restored.
To set the IPv4 VRRP-E slow start timer to 30 seconds, enter the following commands.
device(config)#router vrrp-extended
device(config-VRRP-E-router)#slow-start 30
To set the IPv6 VRRP-E slow start timer to 60 seconds, enter the following commands.
device(config)#ipv6 router vrrp-extended
device(config-ipv6-VRRP-E-router)#slow-start 60
Syntax: [no] slow-start seconds
The seconds variable specifies a value from 1 through 255.
If the Master subsequently comes back up again, the amount of time specified by the VRRP-E slow start timer elapses (in the IPv4
example, 30 seconds) before the Master takes over from the Backup.
The VRRP-E slow start timer is effective only if the VRRP-E Backup router detects another VRRP-E Master (Standby) router. It is not
effective during the initial bootup. The slow start timer is effective on a Backup router if the priority of the Backup router is equal to the
configured priority on the Backup state router.
NOTE
The VRRP-E slow start timer applies only to VRRP-E configurations. It does not apply to VRRP
configurations.
VRRP-E Extension for Server Virtualization
VRRP-E is enhanced with the VRRP-E Extension for Server Virtualization feature so that the Brocade device attempts to bypass the
VRRP-E Master router and directly forward packets to their destinations through interfaces on the Backup router.
Short-path forwarding configuration notes on page 536 shows an example of VRRP-E Extension for Server Virtualization. As shown,
the virtual servers are dynamically moved between Host Server 1 and Host Server 2. Each time the virtual server is activated, it can be
on a different Host Server, and sometimes the traffic crosses the WAN two times before it reaches the client. For example, in the VRRP-E
implementation (without VRRP-E Extension for Server Virtualization), traffic from Virtual server 1 to the client at 10.0.0.X was switched
to the VRRP-E Master router, then routed back to the VRRP-E Backup router, and then routed to the client (the normal forwarding path).
Short-path forwarding limitation
• Short-path forwarding (SPF) applies to IPv4 on Brocade FSX 800, FSX 1600, and ICX 7750 switches only. SPF is not
supported on Brocade FCX or ICX 6xxx switches.
Short-path forwarding configuration notes
• The VRRP-E Master router and Backup router must have routes to all destinations. You should utilize dynamic routing protocols
such as Open Shortest Path First (OSPF) on all routers; otherwise, you must configure the static routes.
Additional VRRP and VRRP-E parameter configuration
FastIron Ethernet Switch Layer 3 Routing
536 53-1003627-04