Standards compliance
VRRP on the switches includes the following:
• Complies with RFC 3768 VRRP version 2.
• Complies with RFC 5798 version 3 with two exceptions—
advertisement intervals
below one second are not
supported, and
accept mode
is not supported (only ping application for virtual-ip-ping).
• Complies with RFC 2787—Definitions of Managed Objects for VRRP, except for support for authentication-
related values.
• Unified standard MIB RFC 6527 supports both IPv4 and IPv6.
• Private MIB hpicfVrrpv3.mib is added to support new IPv6 extensions and VR-specific extensions of the
deprecated, private MIB hpcifVrrp.mib. Global extensions still use hpicfVrrp.mib
Operating notes
• VRRP advertisements not reaching the backups. If a master is forwarding traffic properly, but its backups are
prevented from receiving the master's VRRP advertisements, both routers will operate in the master mode for
the VR. If this occurs, traffic for the applicable gateway will continuously alternate between routers (sometimes
called
flapping
.)
• Deleting an IP address used to support a VR
• VR limitsA VLAN allows up to 32 (16 for the 2930F switch) VRs, and a VR allows up to 32 IP addresses. This
means that one VR can support up to 32 subnets. This capacity enables use of VRRP on all subnets in a
VLAN that has more than 32 subnets.
• Upgrading from VRRPv2Upgrading from a software version that only supports VRRPv2 retains the VRRPv2
mode.
• Downgrading to a VRRPv2 software versionBefore downgrading to a software version that does not support
VRRPv3, ensure that the active configuration does not include IPv6 settings. The downgrade is not supported
if VRRP IPv6 settings are included in the active configuration file.
• Proxy-ARP requests and MAC addressesThe following table shows which MAC address is returned in
response to a proxy-ARP request.
Configured as:
Administratively:
Returns:
owner
Enabled
VRRP MAC address
owner
Disabled
Default VLAN MAC address
backup
Enabled, in master state
VRRP MAC address
backup
Enabled, not in master state
VRRP router does not respond to
proxy-ARP request.
backup
Disabled
Default VLAN MAC address
Chapter 16 Virtual Router Redundancy Protocol (VRRP)
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