Multicast and Routing Guide K/KA/KB.15.15
Figure 52 VIP assignment for owner and backup
Router 1 Configuration
VRID: 1
Status: owner
Virtual IP Addr: 10.10.10.1
Router A
VLAN VID: 10
IP: 10.10.10.1/24
Router B
VLAN VID: 10
IP: 10.10.10.15/24
Switch
VLAN VID: 10
Intranet
Host
Router 2 Configuration
VRID: 1
Status: backup
Virtual IP Addr: 10.10.10.1
Host"A" Gateway: 10.10.10.1
VR 1
10.10.10.1/24
(Virtual IP Address)
Reconfiguring the priority for a backup
When you configure a backup in a VR, it is given a default priority of 100. This command is
intended for use where it is necessary to establish a precedence among the backup routers on the
same network or subnet in a given VR.
Syntax:
priority 1-254
Used in a VR context of a VLAN where the router is configured as a backup. This
command changes the backup's priority and is used to establish the precedence
of a backup where there are multiple backups belonging to the same network or
subnet.
NOTE: An owner is automatically assigned the highest priority, 255, which cannot
be changed unless the owner status is reconfigured to backup.
Default: 100; Range: 1 - 254, where 1 is the lowest precedence
Changing VR advertisement interval and source IP address
Syntax:
vrrp vrid vrid-num advertise-interval 1-40
vrrp ipv6 vrid vrid-num advertise-interval 1-40
• When a VRRP router is operating as master, this value specifies the interval at
which the router sends an advertisement notifying the other VRRP routers on
the network or subnet that a master is active.
• When a VRRP router is operating as a backup, it uses this value to calculate
a master down interval ( 3 x advt-interval.)
Default for IPv4: 1 second; range: 1–40 seconds
Default for IPv6: 1 second; range: 1–40 seconds
For information on advertisements and advertisement intervals, see “Function of the
VRRP advertisement” (page 277).
NOTE: All VRRP routers belonging to the same VR must be configured with the
same advertisement interval. As required in RFC 3768, if a locally configured
advertisement interval does not match the interval received in an inbound VRRP
packet, the VR drops that packet.
254 Virtual Router Redundancy Protocol (VRRP)










