Troubleshooting Vrrp - 3Com 7757 Configuration Manual

Troubleshooting VRRP

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# Configure VLAN 2.
<LSW-B> system-view
[LSW-B] vlan 2
[LSW-B-vlan2] port Ethernet 1/0/6
[LSW-B-vlan2] quit
[LSW-B] interface Vlan-interface 2
[LSW-B-Vlan-interface2] ip address 202.38.160.2 255.255.255.0
# Create backup group 1.
[LSW-B-Vlan-interface2] vrrp vrid 1 virtual-ip 202.38.160.111
# Create backup group 2.
[LSW-B-Vlan-interface2] vrrp vrid 2 virtual-ip 202.38.160.112
# Set the priority for backup group 2.
[LSW-B-Vlan-interface2] vrrp vrid 2 priority 110
n
Normally, multiple backup groups are used in actual use.
Troubleshooting VRRP
You can locate VRRP problems through the configuration and debugging
information. Here are some possible failures you might meet and the
corresponding troubleshooting methods.
Symptom 1: Frequent prompts of configuration errors on the console
This indicates that incorrect VRRP packets are received. It may be because of the
inconsistent configuration of the switches within the backup group, or the
attempt of other devices sending out illegal VRRP packets. The first possible fault
can be solved through modifying the configuration. And as the second possibility
is caused by the malicious attempt of some devices, non-technical measures
should be resorted to.
Symptom 2: More than one master existing within a backup group
There are also 2 reasons. One is short time coexistence of many master switches,
which is normal and needs no manual intervention. Another is the long time
coexistence of many master switches, which may be because the original master
switch and other member switches in a backup group cannot receive VRRP
packets from each other, or receive some illegal packets.
To solve such a problem, an attempt should be made to ping among these masters
and if such an attempt fails, check the connectivity between related devices. If
they can be pinged through, check VRRP configuration. For the configuration of a
VRRP backup group, complete consistency for the number of virtual IP addresses,
each virtual IP address, timer duration and authentication type configured on each
member switch must be guaranteed.