Technical Documentation

Configuring Basic VRRP Support

An interface can be a member of one or more VRRP groups. To configure basic VRRP support, configure VRRP groups on interfaces by including the vrrp-group statement:

vrrp-group group-id {priority number;virtual-address [ addresses ];}

You can include this statement at the following hierarchy levels:

  • [edit interfaces interface-name unit logical-unit-number family inet address address]
  • [edit logical-systems logical-system-name interfaces interface-name unit logical-unit-number family inet address address]

To configure basic VRRP for IPv6 support, configure VRRP group support on interfaces by including the vrrp-group statement:

vrrp-inet6-group group-id {priority number;virtual-inet6-address [ addresses ];virtual-link-local-address ipv6-address;}

You can include this statement at the following hierarchy levels:

  • [edit interfaces interface-name unit logical-unit-number family inet6 address address]
  • [edit logical-systems logical-system-name interfaces interface-name unit logical-unit-number family inet6 address address]

Within a VRRP group, the master virtual router and the backup virtual router must be configured on two different routing platforms.

For each VRRP group, you must configure the following:

  • Group identifier—Assign a value from 0 through 255.
  • Address of one or more virtual routers that are members of the VRRP group—Normally, you configure only one virtual IP address per group. However, you can configure up to eight addresses. Do not include a prefix length in a virtual IP address. The following considerations apply to configuring a virtual IP address:
    • The virtual router IP address must be the same for all routing platforms in the VRRP group.
    • If you configure a virtual IP address to be the same as the physical interface’s address, the interface becomes the master virtual router for the group. In this case, you must configure the priority to be 255 and you must configure preemption by including the preempt statement.
    • If the virtual IP address you choose is not the same as the physical interface’s address, you must ensure that the virtual IP address does not appear anywhere else in the routing platform’s configuration. Verify that you do not use this address for other interfaces, for the IP address of a tunnel, or for the IP address of static ARP entries.
    • You cannot configure a virtual IP address to be the same as the interface’s address for an aggregated Ethernet interface. This configuration is not supported.
    • For VRRP for IPv6, the EUI-64 option cannot be used. In addition, the Duplicate Address Detection (DAD) process will not run for virtual IPv6 addresses.
  • Virtual link local address—(VRRP for IPv6 only) You must explicitly define a virtual link local address for each VRRP for IPv6 group. Otherwise, when you attempt to commit the configuration, the commit request fails. The virtual link local address must be on the same subnet as the physical interface address.
  • Priority for this routing platform to become the master virtual router—Configure the value used to elect the master virtual router in the VRRP group. It can be a number from 1 through 255. The default value for backup routers is 100. A larger value indicates a higher priority. The routing platform with the highest priority within the group becomes the master router.

Note: Mixed tagging (configuring two logical interfaces on the same Ethernet port, one with single-tag framing and one with dual-tag framing) is supported only for interfaces on Gigabit Ethernet IQ2 and IQ PICs. If you include the flexible-vlan-tagging statement at the [edit interfaces interface-name] hierarchy level for a VRRP-enabled interface on a PIC that does not support mixed tagging, VRRP on that interface is disabled. In the output of the show vrrp summary command, the interface status is listed as Down.

Note: If you enable MAC source address filtering on an interface, you must include the virtual MAC address in the list of source MAC addresses that you specify in the source-address-filter statement at the [edit interfaces interface-name] hierarchy. (For more information, see the JUNOS Network Interfaces Configuration Guide.) MAC addresses ranging from 00:00:5e:00:01:00 through 00:00:5e:00:01:ff are reserved for VRRP, as defined in RFC 2378. The VRRP group number must be the decimal equivalent of the last hexadecimal byte of the virtual MAC address.


Published: 2010-04-28