Two Virtual Routers
In the previous, one virtual router example, R2 is not backed up by R1. This example illustrates how to back up R2 by configuring a second virtual router. In this configuration, R1 and R2 are two virtual routers, and the hosts split their traffic between R1 and R2. R1and R2 functions as backups for each other.
Topology
Figure 1-176: Configuring VRRP with Two Virtual Routers
R1
#configure terminal | Enter the Configure mode. |
(config)#router vrrp 1 xe1 | Create a VRRP instance for interface xe1. |
(config-router)#virtual-ip 10.10.10.81 owner | Set the virtual IP address for the VRRP session. Define the default state (owner) of the VRRP router within the virtual router. |
(config-router)#preempt-mode true | Set the preempt mode to specify that the highest priority will function as a backup to master when master is unavailable. |
(config-router)#advertisement-interval 100 | Configure the advertisement interval to 100 centi seconds (value must be a multiple of 5). |
(config-router)# v2-compatible | Enable the v2-compatible |
(config-router)#authentication text abcd | Configure the authentication text to specify that as simple text for vrrpv2 packets, accept only 8 characters |
(config-router)#enable | Enable the VRRP session 1 on the router. |
(config-router)#commit | Commit the candidate configuration to the running configuration. |
(config-router)#exit | Exit Router mode and enter the Configure mode. |
(config)#router vrrp 2 xe1 | Create a VRRP instance for interface xe1. |
(config-router)#virtual-ip 10.10.10.82 | Set the virtual IP address for the VRRP session. |
(config-router)#priority 200 | Configure the priority to 200 (less than 255), because R2 is the Backup router. |
(config-router)#preempt-mode true | Set the preempt mode to specify that the highest priority will function as a backup to master when master is unavailable. |
(config-router)#advertisement-interval 100 | Configure the advertisement interval to 100 centi seconds (value must be a multiple of 5). |
(config-router)# v2-compatible | Enable the v2-compatible |
(config-router)#authentication text abcd | Configure the authentication text to specify that as simple text for vrrpv2 packets, accept only 8 characters |
(config-router)#enable | Enable the VRRP session two on the router. |
(config-router)#commit | Commit the candidate configuration to the running configuration. |
(config-router)#exit | Exit Router mode. |
R2
#configure terminal | Enter the Configure mode. |
(config)#router vrrp 1 xe1 | Create a VRRP instance for interface xe1. |
(config-router)#virtual-ip 10.10.10.81 | Set the virtual IP address for the VRRP session. |
(config-router)#priority 200 | Configure the priority to 200 (less than 255), because R2 is the Backup router. |
(config-router)#preempt-mode true | Set the preempt mode to specify that the highest priority will function as a backup to master when master is unavailable. |
(config-router)#advertisement-interval 100 | Configure the advertisement interval to 100 centi seconds (value must be a multiple of 5). |
(config-router)# v2-compatible | Enable the v2-compatible |
(config-router)#authentication text abcd | Configure the authentication text to specify that as simple text for vrrpv2 packets, accept only 8 characters |
(config-router)#enable | Enable the VRRP session 1 on the router. |
(config-router)#commit | Commit the candidate configuration to the running configuration. |
(config-router)#exit | Exit the Router mode and enter the Configure mode. |
(config)#router vrrp 2 xe1 | Create a VRRP instance for interface xe1 |
(config-router)#virtual-ip 10.10.10.82 owner | Set the virtual IP address for the VRRP session. Define the default state (owner) of the VRRP router within the virtual router. |
(config-router)#preempt-mode true | Set the preempt mode to specify that the highest priority will function as a backup to master when master is unavailable. |
(config-router)#advertisement-interval 100 | Configure the advertisement interval to 100 centi seconds (value must be a multiple of 5). |
(config-router)# v2-compatible | Enable the v2-compatible |
(config-router)#authentication text abcd | Configure the authentication text to specify that as simple text for vrrpv2 packets, accept only 8 characters |
(config-router)#enable | Enable the VRRP session two on the router. |
(config-router)#commit | Commit the candidate configuration to the running configuration. |
(config-router)#exit | Exit Router mode. |
Validation
The following outputs on R1and R2 display the complete configuration for each session on R1 and R2. In session one, R1 is the master router, and in session two R2 is the master router.
R1
R1#sh vrrp 1 eth1 VRRP Version: 3 VMAC enabled
Backward Compatibility disabled
Address family IPv4
VRRP Id: 1 on interface: xe1
State: AdminUp - Master
Virtual IP address: 10.10.10.81 (Owner)
Virtual MAC address is 0000.5e00.0101
Operational primary IP address: 10.10.10.81
Operational master IP address: 10.10.10.81
Priority is 255
Advertisement interval: 100 centi sec
Master Advertisement interval: 100 centi sec
Virtual router uptime: 0 hours 1 minutes 25 seconds (8500 centi sec)
Master uptime: 0 hours 1 minutes 18 seconds (7800 centi sec)
Accept mode: FALSE Preempt mode: TRUE
Auth-type: simple text, String: abcd
Multicast membership on IPv4 interface eth1: JOINED V2-Compatible: TRUE
R1#sh vrrp 2 eth1 VRRP Version: 3 VMAC enabled
Backward Compatibility disabled
Address family IPv4
VRRP Id: 2 on interface: xe1
State: AdminUp - Backup
Virtual IP address: 10.10.10.82 (Not-owner)
Virtual MAC address is 0000.5e00.0102
Operational primary IP address: 10.10.10.81
Operational master IP address: 10.10.10.82 Priority is 200
Advertisement interval: 100 centi sec
Master Advertisement interval: 100 centi sec
Virtual router uptime: 0 hours 2 minutes 3 seconds (12300 centi sec)
Skew time: 80 centi sec
Master Down Interval: 380 centi sec
Accept mode: FALSE Preempt mode: TRUE
Auth-type: simple text, String: abcd
Multicast membership on IPv4 interface eth1: JOINED V2-Compatible: TRUE
R2
R2#sh vrrp 1 eth1 VRRP Version: 3 VMAC enabled
Backward Compatibility disabled
Address family IPv4
VRRP Id: 1 on interface: xe1
State: AdminUp - Backup
Virtual IP address: 10.10.10.81 (Not-owner)
Virtual MAC address is 0000.5e00.0101
Operational primary IP address: 10.10.10.82
Operational master IP address: 10.10.10.81
Priority is 200
Advertisement interval: 100 centi sec
Master Advertisement interval: 100 centi sec
Virtual router uptime: 0 hours 0 minutes 37 seconds (3700 centi sec)
Skew time: 80 centi sec
Master Down Interval: 380 centi sec
Accept mode: FALSE Preempt mode: TRUE
Auth-type: simple text, String: abcd
Multicast membership on IPv4 interface eth1: JOINED
V2-Compatible: TRUE
R2#sh vrrp 2 eth1 VRRP Version: 3 VMAC enabled
Backward Compatibility disabled
Address family IPv4
VRRP Id: 2 on interface: xe1
State: AdminUp - Master
Virtual IP address: 10.10.10.82 (Owner)
Virtual MAC address is 0000.5e00.0102
Operational primary IP address: 10.10.10.82
Operational master IP address: 10.10.10.82 Priority is 255
Advertisement interval: 100 centi sec
Master Advertisement interval: 100 centi sec
Virtual router uptime: 0 hours 0 minutes 12 seconds (1200 centi sec)
Master uptime: 0 hours 1 minutes 18 seconds (7800 centi sec)
Accept mode: FALSE
Preempt mode: TRUE
Auth-type: simple text, String: abcd
Multicast membership on IPv4 interface eth1: JOINED
V2-Compatible: TRUE
R2#
Last modified date: 08/28/2023