BLADE OS™ Application Guide HP GbE2c Ethernet Blade Switch for c-Class BladeSystem Version 5.1 Advanced Functionality Software

Table Of Contents
BLADE OS 5.1 Application Guide
262 Glossary BMD00113, September 2009
VIR (Virtual Interface
Router)
A VRRP address that is an IP interface address shared between two or more
virtual routers.
Virtual Router
A shared address between two devices utilizing VRRP, as defined in RFC 2338.
One virtual router is associated with an IP interface. This is one of the IP
interfaces that the switch is assigned. All IP interfaces on the GbE2c must be in a
VLAN. If there is more than one VLAN defined on the switch, then the VRRP
broadcasts will only be sent out on the VLAN of which the associated IP interface
is a member.
VRID (Virtual Router
Identifier)
In VRRP, a numeric ID is used by each virtual router to create its MAC address
and identify its peer for which it is sharing this VRRP address. The VRRP MAC
address as defined in the RFC is 00-00-5E-00-01-<VRID>. For a virtual router
with a VRID greater than 255, the following block of MAC addresses is
allocated: 00:0F:6A:9A:40:00 through 00:0F:6A:9A:47:FF.
If you have a VRRP address that two switches are sharing, then the VRID number
needs to be identical on both switches so each virtual router on each switch knows
with whom to share.
VRRP (Virtual Router
Redundancy Protocol)
A protocol that acts very similarly to Cisco's proprietary HSRP address sharing
protocol. The reason for both of these protocols is so devices have a next hop or
default gateway that is always available. Two or more devices sharing an IP
interface are either advertising or listening for advertisements. These
advertisements are sent via a broadcast message to an address such as 224.0.0.18.
With VRRP, one switch is considered the master and the other the backup. The
master is always advertising via the broadcasts. The backup switch is always
listening for the broadcasts. Should the master stop advertising, the backup will
take over ownership of the VRRP IP and MAC addresses as defined by the
specification. The switch announces this change in ownership to the devices
around it by way of a Gratuitous ARP, and advertisements. If the backup switch
didn't do the Gratuitous ARP the Layer 2 devices attached to the switch would not
know that the MAC address had moved in the network. For a more detailed
description, refer to RFC 2338.