HP 3500YL - Manual (Page 338)

Virtual Router Redundancy Protocol (VRRP)
General Operation
Virtual Router (VR)
A Virtual Router (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 multinetted VLAN, multiple VRs can be configured. The Owner
operates as the VR’s Master unless it becomes unavailable, in which case the
highest-priority backup becomes the VR’s Master.
A VR includes the following:
■ a virtual router identification (VRID) configured on all VRRP routers
in the same network or, in the case of a multinetted VLAN, on all
routers in the same subnet
■ the same virtual IP address configured on each instance of the same
VR
■ a status of either Owner or Backup configured on each instance of
the same VR (On a given VR there can be one Owner and One or more
Backups.)
■ a priority level configured on each instance of the VR (On the Owner
router the highest priority setting, 255, is automatically fixed. On
Backups, the default priority setting is 100 and is configurable.)
■ a VR MAC address (not configurable)
Where a VLAN is configured with only one network (IP address), one VR is
allowed in that VLAN. In a multinetted VLAN, there can be one VR per subnet,
with a maximum of 32 VRs in any combination of Masters and Backups.
N o t e All routers in a given VR must belong to the same network (or subnet, in the
case of a multinetted VLAN).
Virtual IP Address
The virtual IP address associated with a VR must be a real IP address already
configured in the associated VLAN interface on the Owner router in the VR.
Also, the Owner and all other (Backup) routers belonging to the VR have this
IP address configured in their VRID contexts as the virtual IP address. In
figure 6-1 on page 6-6, 10.10.100.1 is a real IP address configured on VLAN 100
in Router 1, and is the virtual IP address associated with VR 1.
6-8