VRRP
7705 SAR OS Router Configuration Guide 217
The priority value also dictates the skew time added to the master timeout period.
IP Addresses
Each virtual router with the same VRID is defined with the same set of IP addresses. These
are the IP addresses used by hosts on the LAN as gateway addresses. Multi-netting supports
eight IP addresses on the IP interface.
Message Interval and Master Inheritance
Each virtual router is configured with a message interval per VRID within which it
participates. This parameter must be the same for every virtual router with the VRID.
For IPv4, the default message interval is 1 s and can be configured between 100 ms and 255 s,
900 ms.
The message interval field in every received VRRP advertisement message must match the
locally configured message interval. If a mismatch occurs, depending on the inherit
configuration, the current message interval setting of the master can be used to operationally
override the locally configured message interval setting. If the current master changes, the
new master setting is used. If the local virtual router becomes master, the locally configured
message interval is enforced.
If a VRRP advertisement message is received with a message interval set to a value different
from the local value and the inherit parameter is disabled, the message is discarded without
processing.
The virtual router master uses the message interval as a timer, specifying when to send the
next VRRP advertisement message. Each virtual router backup uses the message interval
(with the configured local priority) to derive the master down timer value.
VRRP advertisement messages that are fragmented or contain IP options (IPv4) require a
longer configured message interval.
The virtual router instance can inherit the master VRRP router’s message interval timer,
which is used by backup routers to calculate the master down timer.
The inheritance is only configurable in the non-owner context. It is used to allow the current
virtual router master to dictate the master down timer for all virtual router backups.
To Next Page
Loading...
