Virtual Router Redundancy Protocol (VRRP) is designed to eliminate the single point of failure inherent in the static default routed environment. VRRP specifies an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. The VRRP router controlling the IP address(es) associated with a virtual router is called the Master, and forwards packets sent to these IP addresses. This document explains how to configure and verify VRRP in EX switches.
For Gigabit Ethernet interfaces, 10-Gigabit Ethernet interfaces, and logical interfaces on EX Series switches, Virtual Router Redundancy Protocol (VRRP) can be configured. The switches act as virtual routing platforms. VRRP enables hosts on a LAN to make use of redundant routing platforms on that LAN without requiring more than the static configuration of a single default route on the hosts. The VRRP routing platforms share the IP address corresponding to the default route configured on the hosts. At any time, one of the VRRP routing platforms is the master (active) and the others are backups. If the master routing platform fails, one of the backup routing platforms becomes the new master, providing a virtual default routing platform and enabling traffic on the LAN to be routed without relying on a single routing platform. Using VRRP, a backup EX Series switch can take over a failed default switch within few seconds. This is done with minimum VRRP traffic and without any interaction with the hosts.
Configure the VRRP group for which each of the switches sw1 and sw2 to be master and backup. Higher value of priority reflects higher priority and therefore will the switch will become master for the VRRP group.
user@sw1# set interfaces vlan unit 30 family inet address 200.200.251.2/29 vrrp-group 1 virtual-address 200.200.251.1
user@sw1# set interfaces vlan unit 30 family inet address 200.200.251.2/29 vrrp-group 1 priority 200
user@sw2# set interfaces vlan unit 30 family inet address 200.200.251.3/29 vrrp-group 1 virtual-address 200.200.251.1
user@sw2# set interfaces vlan unit 30 family inet address 200.200.251.3/29 vrrp-group 1 priority 100
By default, a higher-priority backup router preempts a lower-priority master router. To explicitly enable the master router to be preempted, include the preempt statement:
user@sw1# set interfaces vlan unit 30 family inet address 200.200.251.2/29 vrrp-group 1 preempt
user@sw2# set interfaces vlan unit 30 family inet address 200.200.251.3/29 vrrp-group 1 preempt
To configure an interface to accept packets destined for the virtual IP address, include the accept-data statement
user@sw1# set interfaces vlan unit 30 family inet address 200.200.251.2/29 vrrp-group 1 accept-data
user@sw2# set interfaces vlan unit 30 family inet address 200.200.251.3/29 vrrp-group 1 accept-data
user@sw1# show interfaces vlan.30
family inet {
address 200.200.251.2/29 {
vrrp-group 1 {
virtual-address 200.200.251.1;
priority 200;
preempt;
accept-data;
}
}
}
user@sw2# show interfaces vlan.30
family inet {
address 200.200.251.3/29 {
vrrp-group 1 {
virtual-address 200.200.251.1;
priority 200;
preempt;
accept-data;
}
}
}