Virtual Router Redundancy Protocol (VRRP) defined in RFC 5798 is designed to address an issue when default gateway for end clients fails. Using VRRP protocol, it is possible to create a group consisting of several NETX routers that form a virtual router. The VRRP group has one master and multiple backups routers and provides a virtual IP address. The hosts on the subnet use the virtual IP address as their default network gateway to communicate with external networks.
VRRP avoids single points of failure. When the master in the VRRP group fails, another router in the VRRP group takes over. The switchover is complete without causing dynamic route recalculation, route re-discovery, gateway reconfiguration on the hosts, or traffic interruption.
It is possible to configure VRRP group in the interface context using
vrrp command. The following example create a VRRP group with virtual IPv4 address 192.168.1.254.
netx# interface ve2 netx(if-ve2)# vrrp 1 ipv4 192.168.1.254
show ipv4 vrrp command can be used to display details about the VRRP state, last transition, priority, etc. The command displays all configured VRRP groups if it is entered in the
global context. If the command is entered in context of an interface, it displays only VRRP groups configured on the interface.
netx# show ipv4 vrrp INTERFACE VRRP ID PRIO VIRTUAL IP STATE MASTER IP LAST TRANSITION ve2 1 100 192.168.1.254 BACKUP 192.168.1.100 Sat Nov 3 11:20:20 2018
Detailed information about the VRRP group can be displayed in the interface context using
show vrrp detail command.
netx# interface ve2 netx(if-ve2)# show vrrp detail Interface: ve2, VRRP ID: 1 Accept: enabled Advert interval: 1 sec Authentication type: none Gratuitous ARP delay: 5 Gratuitous ARP lower priority delay: 5 Gratuitous ARP lower priority repeat: 5 Gratuitous ARP refresh: 0 Gratuitous ARP refresh repeat: 1 Gratuitous ARP repeat: 5 IP: 192.168.1.254/32 dev ve2 scope global Last transition: 1541240420 (Sat Nov 3 11:20:20 2018) Listening device: ve2 Master priority: 100 Master router: 192.168.1.100 Preempt: enabled Priority: 100 Promote_secondaries: disabled Send advert after receive higher priority advert: false Send advert after receive lower priority advert: true State: BACKUP Using src_ip: 192.168.1.102 VRRP Version: 2 Virtual Router ID: 1
Set a priority
The NETX router assigned the highest priority becomes the master router. By default, priority is set to 100. It is possible to change the priority value by using
priority command. The following example shows how to change the priority value for VRRP Group ID 1.
netx# interface ve2 ! display vrrp info and check the priority netx(if-ve2)# show vrrp INTERFACE VRRP ID PRIO VIRTUAL IP STATE MASTER IP LAST TRANSITION ve2 1 100 192.168.1.254 BACKUP 192.168.1.100 Sat Nov 3 11:20:20 2018 ! change priority to 150 to became a master node netx(if-ve2)# vrrp 1 priority 150 netx(if-ve2)# show vrrp INTERFACE VRRP ID PRIO VIRTUAL IP STATE MASTER IP LAST TRANSITION ve2 1 150 192.168.1.254 MASTER local Sat Nov 3 17:29:30 2018