Configuring Interface Tracking - 3Com 3C13636 Configuration Manual

3Com Router 3000 Ethernet Family
Configuration Guide
In normal circumstances, Router A functions as the gateway. When it is shut down or
fails, Router B takes over. The preemption mode however allows Router A to become
the master again after it recovers.

3.4.2 Configuring Interface Tracking

I. Network requirements
Sometimes even when Router A is operating, you may prefer to use Router B as the
gateway because the Internet connection of Router A is unavailable. To accommodate
to this situation, you may configure interface tracking.
To facilitate explanation, set the VRID number to 1 and configure authorization key and
VRRP timer (which are optional in this application).
II. Network diagram
See Figure 3-3.
III. Configuration procedure
Configure Router A:
# Create a standby group.
[3Com-Ethernet1/0/0] vrrp vrid 1 virtual-ip 202.38.160.111
# Set the priority of the standby group.
[3Com-Ethernet1/0/0] vrrp vrid 1 priority 120
# Configure the authentication key of the standby group.
[3Com-Ethernet1/0/0] vrrp authentication-mode md5 3COM
# Configure the master to send VRRP packets at intervals of five seconds.
[3Com-Ethernet1/0/0] vrrp vrid 1 timer advertise 5
# Set the interface to be tracked.
[3Com-Ethernet1/0/0] vrrp vrid 1 track serial2/0/0 reduced 30
Configure Router B:
# Create a standby group.
[3Com-Ethernet1/0/0] vrrp vrid 1 virtual-ip 202.38.160.111
# Configure the authentication key of the standby group.
[3Com-Ethernet1/0/0] vrrp authentication-mode md5 3COM
# Configure the master to send VRRP packets at intervals of five seconds.
[3Com-Ethernet1/0/0] vrrp vrid 1 timer advertise 5
[3Com-Ethernet1/0/0] vrrp vrid 1 preempt-mode timer delay 5
3Com Corporation
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Chapter 3 VRRP Configurations