HP 3500YL - Manual (Page 341)

Virtual Router Redundancy Protocol (VRRP)
General Operation
VRRP and ARP
The Master for a given VR responds to ARP requests for the virtual IP
addresses with the VR’s assigned MAC address. The virtual MAC address is
also used as the source MAC address for the periodic advertisements sent by
the current Master.
The VRRP router responds to ARP requests for non-virtual IP addresses (IP
addresses on a VLAN interface that are not configured as virtual IP addresses
for any VR on that VLAN) with the system MAC address.
General Operating Rules
■ IP routing must be enabled on the router before enabling VRRP.
■ IP must be enabled on a VLAN before creating a VR instance on the
VLAN.
■ virtual IP address:
• On an Owner: The virtual IP address configured in a VR instance must
match one of the IP addresses configured in the VLAN interface on
which the VR is configured.
• On a Backup: The virtual IP address configured in a VR instance
cannot be a “real” IP address configured in a VLAN interface on that
router.
N o t e The virtual IP address configured for one VR cannot be configured on
another VR.
■ Before changing a router from Owner to Backup, or the reverse, the
virtual IP address must be removed from the configuration.
■ The priority configuration on an Owner can only be 255. The priority
configuration on a Backup must be 254 or lower; the default being 100.
■ advertisement intervals:
• A VRRP router must be configured as an Owner or Backup before
configuring the advertisement interval.
• If a VRRP router has a different advertisement interval than a VRRP
packet it receives, the router drops the packet. For this reason, the
advertisement interval must be the same for the Owner and all Back­
ups in the same VR.
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