VR parameter
Router 1 VR
configuration
Router 2 VR
configuration
Operation
VR Source MAC Address
00-00-5E-00-01-01
For any VR in any VLAN,
this is always defined as
00-00-5E-00-01-
VRID
and is not configurable.
Priority
255 (Default)
100 (Default)
The router configured as
owner in any VR is
automatically assigned the
highest priority (255.)
backup routers are
assigned a default priority
of 100, which can be
reconfigured.
In the preceding example:
• Host "A" uses 10.10.100.1 as its next-hop gateway out of the subnet, as represented by the VR (VR 1.)
◦ Router 1 (the configured owner) advertises itself as the master in the VR supporting the gateway and:
– "Owns" the VR's (virtual) IP address
– Transmits ARP responses that associate the VR's VIP with the (shared) source MAC address for VR 1.
◦ During normal operation, Router 1 forwards the routed traffic for host "A."
• If Router 1 fails or otherwise becomes unavailable:
1.
Router 1 advertisements of its master status for VR 1 fail to reach Router 2 (which is the only configured
backup.)
2.
After the time-out period for receiving master advertisements expires on Router 2, the VR initiates a failover
to Router 2 and it becomes the new master of the VR.
3.
Router 2 advertises itself as the master of the VR supporting the gateway and:
◦ Takes control of the VR's (virtual) IP address
◦ Begins transmitting ARP responses that associate the VR's VIP with the (shared) source MAC address
for VR 1
4.
Host "A" routed traffic then moves through Router 2.
• If Router 1 again becomes available:
1.
Router 1 resumes advertising itself as the master for the VR and sends ARP responses that associate the
VR's VIP with the (shared) source MAC address for VR 1.
2.
Router 2 receives the advertisement from Router 1 and ceases to operate as the VR's master, and halts
further transmission of its own VRRP advertisements and ARP responses related to VR 1.
3.
The VR executes a failback to Router 1 as master, and Host "A" traffic again moves through Router 1.
Virtual router (VR)
A VR instance consists of one owner router and one or more backup routers belonging to the same network. Any
VR instance exists within a specific VLAN, and all members of a given VR must belong to the same subnet. In a
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Aruba 3810 / 5400R Multicast and Routing Guide for ArubaOS-
Switch 16.08
