Configuring the Advertisement Interval for the VRRP Primary Router
By default, the primary router sends VRRP advertisement packets every second to all members of the VRRP group. These packets indicate that the primary router is still operational. If the primary router fails or becomes unreachable, the backup router with the highest priority value becomes the new primary router.
You can modify the advertisement interval in seconds or in milliseconds. The interval must be the same for all routing platforms in the VRRP group.
For VRRP for IPv6, you must configure IPv6 router advertisements
for the interface on which VRRP is configured to send IPv6 router
advertisements for the VRRP group. To do so, include the interface interface-name
statement at the [edit protocols
router-advertisement]
hierarchy level. (For information about
this statement and guidelines, see the Junos OS Routing Protocols Library for Routing Devices.) When
an interface receives an IPv6 router solicitation message, it sends
an IPv6 router advertisement to all VRRP groups configured on it.
In the case of logical systems, IPv6 router advertisements are not
sent to VRRP groups.
The primary VRRP for an IPv6 router must respond to a
router solicitation message with the virtual IP address of the router.
However, when the interface interface-name
statement is included at the [edit protocols router-advertisement]
hierarchy level, the backup VRRP for an IPv6 router might send a
response before the VRRP primary responds, so that the default route
of the client is not set to the primary VRRP router’s virtual
IP address. To avoid this situation, include the virtual-router-only
statement at the [edit protocols router-advertisement interface interface-name]
hierarchy level. When this statement
is included, router advertisements are sent only for VRRP IPv6 groups
configured on the interface (if the groups are in the primary state).
You must include this statement on both the primary and backup VRRP
for IPv6 routers.
In an EVPN network, including the virtual-router-only
statement at the [edit protocols router-advertisement interface interface-name]
hierarchy level restricts the router
advertisements to be sent only for the link local virtual-gateway-address.
This topic contains the following sections:
Modifying the Advertisement Interval in Seconds
To modify the time, in seconds, between the sending of
VRRP advertisement packets, include the advertise-interval
statement:
advertise-interval seconds;
The interval can be from 1 through 255 seconds.
You can include this statement at the following hierarchy levels:
[edit interfaces interface-name unit logical-unit-number family inet address address vrrp-group group-id]
[edit logical-systems logical-system-name interfaces interface-name unit logical-unit-number family inet address address vrrp-group group-id]
When VRRPv3 is enabled, the advertise-interval
statement cannot be used to configure advertisement intervals. Instead,
use the fast-interval
statement to configure advertisement
intervals.
Modifying the Advertisement Interval in Milliseconds
To modify the time, in milliseconds, between the sending
of VRRP advertisement packets, include the fast-interval
statement:
fast-interval milliseconds;
The interval can be from 10 through 40,950 milliseconds.
You can include this statement at the following hierarchy levels:
[edit interfaces interface-name unit logical-unit-number family (inet | inet6) address address (vrrp-group | vrrp-inet6-group) group-id]
[edit logical-systems logical-system-name interfaces interface-name unit logical-unit-number family (inet | inet6) address address (vrrp-group | vrrp-inet6-group) group-id]
In the VRRP PDU, Junos OS sets the advertisement interval
to 0. When you configure VRRP with other vendors’ routers, the fast-interval
statement works correctly only when the other
routers also have an advertisement interval set to 0 in the VRRP PDUs.
Otherwise, Junos OS interprets other routers’ settings as advertisement
timer errors.
To modify the time, in milliseconds, between the sending
of VRRP for IPv6 advertisement packets, include the inet6-advertise-interval
statement:
inet6-advertise-interval ms;
The range of values is from 100 through 40,000 milliseconds (ms).
You can include this statement at the following hierarchy levels:
[edit interfaces interface-name unit logical-unit-number family inet6 address address vrrp-inet6-group group-id]
[edit logical-systems logical-system-name interfaces interface-name unit logical-unit-number family inet6 address address vrrp-inet6-group group-id]
When VRRPv3 is enabled, the inet6-advertise-interval
statement cannot be used to configure advertisement intervals. Instead,
use the fast-interval
statement to configure advertisement
intervals.