3Com 4500 PWR 26-Port Configuration Manual page 230

Network diagram
Figure 19-3 Network diagram for VLAN interface backup
Configuration procedure
Configure the IP addresses of all the interfaces as shown in
omitted.
# Enter system view.
<SwitchA> system-view
# Create auto detected group 10.
[SwitchA] detect-group 10
# Add the IP address of 10.1.1.4 to detected group 10 to detect the reachability of the IP address, with
the IP address of 192.168.1.2 as the next hop, and the detecting number set to 1.
[SwitchA-detect-group-10] detect-list 1 ip address 10.1.1.4 nexthop 192.168.1.2
[SwitchA-detect-group-10] quit
# Specify to enable VLAN-interface 2 when the result of detected group 10 is unreachable.
[SwitchA] interface vlan-interface 2
[SwitchA-Vlan-interface2] standby detect-group 10
Figure 19-3. The configuration procedure is
19-6