Design Reference

configuring the VRRP hold down timer to a minimum of 1.5 times the IGP convergence
time is sufficient. For OSPF, Avaya recommends that you use a value of 90 seconds if
you use the default OSPF timers.
• Implement VRRP BackupMaster for an active-active configuration (BackupMaster works
across multiple switches that participate in the same VRRP domain.).
• Configure VRRP priority as 200 to configure VRRP Master.
• Stagger VRRP Masters between switches in the core to balance the load between
switches.
• If you implement VRRP Fast, you create additional control traffic on the network and also
create a greater load on the CPU. To reduce the convergence time of VRRP, the VRRP
Fast feature allows the modification of VRRP timers to achieve subsecond failover of
VRRP. Without VRRP Fast, normal convergence time is approximately 3 seconds.
• Do not use VRRP BackupMaster and critical IP at the same time. Use one or the other.
• When you implement VRRP on multiple VLANs between the same switches, Avaya
recommends that you configure a unique VRID on each VLAN.
VRRP and spanning tree
Virtual Services Platform 4000 can use one of two spanning tree protocols. These include the
Rapid Spanning Tree Protocol (RSTP) and the Multiple Spanning Tree Protocol (MSTP).
VRRP protects clients and servers from link or aggregation switch failures. Configure the
network to limit the amount of time a link is down during VRRP convergence. The following
figure shows two possible configurations of VRRP and spanning tree; configuration A is optimal
and configuration B is not.
Virtual Router Redundancy Protocol
Network Design Reference for Avaya VSP 4000 February 2014 59