
f. Configure VRRP to implement virtual gateway redundancy.
After VRRP is configured on CORE1 and CORE2, the access switches forward traffic
to CORE1. If CORE1 fails, a VRRP switchover occurs and CORE2 becomes the
master. The access switches then forward traffic to CORE2.
Create VRRP groups 1 and 2 on CORE1 and CORE2. Set the priority of CORE1 to
120 and set the preemption delay to 20s so that CORE1 functions as the master in
VLANs 10 and 20.
1
[CORE1]
interface Vlanif 10
[CORE1-Vlanif10]
vrrp vrid 1 virtual-ip 192.168.10.3
//Configure a
virtual IP address for VRRP group 1.
[CORE1-Vlanif10]
vrrp vrid 1 priority 120
//Set the priority of
CORE1 to 120.
[CORE1-Vlanif10]
vrrp vrid 1 preempt-mode timer delay 20
[CORE1-Vlanif10]
quit
[CORE1]
interface Vlanif 20
[CORE1-Vlanif20]
vrrp vrid 2 virtual-ip 192.168.20.3
//Configure a
virtual IP address for VRRP group 2.
[CORE1-Vlanif20]
vrrp vrid 2 priority 120
[CORE1-Vlanif20]
vrrp vrid 2 preempt-mode timer delay 20
[CORE1-Vlanif20]
quit
CORE2 uses the default priority and functions as the backup in VLANs 10 and 20.
[CORE2]
interface Vlanif 10
[CORE2-Vlanif10]
vrrp vrid 1 virtual-ip 192.168.10.3
[CORE2-Vlanif10]
quit
[CORE2]
interface Vlanif 20
[CORE2-Vlanif20]
vrrp vrid 2 virtual-ip 192.168.20.3
[CORE2-Vlanif20]
quit
2
A physical loop exists between CORE1, CORE2, and ACC1, the actual
links do not form a loop, and STP is enabled on the switches (Sx7 series)
by default. To prevent the loop from affecting the VRRP master and backup
status on CORE1 and CORE2, disable STP on upstream interfaces of
ACC1. The example below shows the configuration on ACC1.
[ACC1]
interface GigabitEthernet 0/0/3
[ACC1-GigabitEthernet0/0/3]
stp disable
//Disable STP on the upstream
interface GE0/0/3.
[ACC1-GigabitEthernet0/0/3]
quit
[ACC1]
interface GigabitEthernet 0/0/4
[ACC1-GigabitEthernet0/0/4]
stp disable
[ACC1-GigabitEthernet0/0/4]
quit
If no loop exists on the network, you can also run the
stp disable
command to disable
STP on the access switch.
[ACC1]
stp disable
Warning: The global STP state will be changed. Continue? [Y/N] y
34