Version [2] : 2
Null authentication compatibility [False] : False
Primary IP Address : Lowest
IP Address
----------------
10.10.10.1
VRRP configuration for Router 2 (R2) in Example of a basic VRRP configuration
switch(config)# router vrrp
switch(config)# vlan 10
switch(vlan-10)# vrrp vrid 1
switch(vlan-10-vrid-1)# backup
switch(vlan-10-vrid-1)# virtual-ip-address 10.10.10.1
switch(vlan-10-vrid-1)# enable
switch(vlan-10-vrid-1)# show vrrp vlan 10 vrid 1 config
VRRP Virtual Router Configuration Information
VLAN ID : 10
Virtual Router ID : 1
Administrative Status [Disabled] : Enabled
Mode [Uninitialized] : backup
Priority [100] :100
Advertisement Interval [1] : 1
Preempt Mode [True] : True
Preempt Delay time [0] : 0
Respond to Virtual IP Ping Requests [Yes] : Yes
Version [2] : 2
Null authentication compatibility [False] : False
Primary IP Address : Lowest
IP Address
----------------
10.10.10.1
Associating more than one VIP with a VR
If a VLAN is configured with more than 32 (16 for the 2930F switch) subnets and it is necessary to apply VRRP to
all of these subnets, it is necessary to associate more than one VIP with a VR.
Because a VLAN on the routers supports up to 32 (16 for the 2930F switch) VRs, applying VRRP to a higher
number of subnets in the VLAN requires multiple VIPs in one or more VRs.
If the owner of a VR is associated with multiple VIPs, the backup routers belonging to the same VR must also be
associated with the same set of VIPs. If the VIPs on the owner are not also on the backups, a misconfiguration
exists. VRRP advertisement packets sent by the VR master will be dropped by the VR backups because of a
mismatch among VIPs.
Dynamically changing the priority of the VR
The dynamic priority change feature provides the ability to dynamically change the priority of the virtual router
(VR) when certain events occur. The backup VR releases VIP control by reducing its priority when tracked entities
such as ports, trunks, or VLANs go down. You can also force the backup to take ownership of the VR if you have
previously caused it to release control.
Chapter 16 Virtual Router Redundancy Protocol (VRRP)
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