Configuring VRRP
VRRPv3 Configuration Overview
OmniSwitch AOS Release 7 Network Configuration Guide
June 2013
page 22-21
In the above example, the
vrrp3 address
command specifies that VRRPv3 virtual router 6 on VLAN 4
will be used to
backup IPv6 address
fe80::200:5eff:fe00:20a
. The virtual router is then enabled with
the
vrrp3
command.
If a virtual router is to be the IP address owner, then all addresses on the virtual router must match an
address on the switch interface. This includes the virtual router's link local address. In other words, a
virtual router can not be the IP address owner if its link local address does not match the interface link
local address.
To remove an IPv6 address from a virtual router, use the
no
form of the
vrrp3 address
command. For
example:
-> vrrp3 6 4 admin-state disable
-> vrrp3 6 4 no address fe80::200:5eff:fe00:20a
In this example, VRRPv3 virtual router 6 is disabled. (A VRRPv3 virtual router must be disabled before
IPv6 addresses may be added/removed from the router.) IP address
fe80::200:5eff:fe00:20a
is then
removed from the virtual router with the
no
form of the
vrrp3 address
command.
Configuring the VRRPv3 Advertisement Interval
The advertisement interval is configurable, but all virtual routers with the same VRID must be configured
with the same value. If the advertisement interval is set differently for a master router and a backup router,
VRRPv3 packets may be dropped because the newly configured interval does not match the interval indi-
cated in the packet. The backup router will then take over and send a neighbor advertisement
,
which
includes the virtual router IP address and the virtual router MAC address. In addition to creating duplicate
IP/MAC address messages, both routers will begin forwarding packets sent to the virtual router MAC
address. This will result in forwarding duplicate packets.
To avoid duplicate addresses and packets, make sure the advertisement interval is configured the same on
both the master and the backup router.
To configure the advertisement interval, use the
command with the
interval
keyword. For example:
-> vrrp3 6 4 admin-state disable
-> vrrp3 6 4 interval 500
In this example, VRRPv3 virtual router 6 is disabled. (If you are modifying an existing virtual router, the
virtual router must be disabled before it may be modified.) The
vrrp3
command is then used to set the
advertising interval for virtual router 6 to 500 centiseconds.
Configuring the VRRPv3 Virtual Router Priority
VRRPv3 functions with one master virtual router and at least one backup virtual router. A priority value
determines the role each router plays. It also decides the selection of backup routers for taking over as the
master router, if the master router is unavailable.
Priority values range from 1 to 255. A value of 255 indicates that the virtual router owns the IPv6 address;
that is, the router contains the real physical interface to which the IPv6 address is assigned. The switch can
change the default value and set it to 255 if it detects that the router is the IPv6 address owner. The value
cannot be set to 255 if the router is not the IPv6 address owner.
The IPv6 address owner will always be the master router if it is available. If more than one backup router
is configured, their priority values should be configured with different values, so that the backup with the
higher value will take over for the master. The priority parameter may be used to control the order in