Configure backup for 3Com superstack switches
Kiwi CatTools supports many 3Com superstack switches: 610 / 630 / 1100 / 3300 / 3300 FX / 3300XM / 3300TM / 3300SM / 3300MM. However, it has been found that 3Com switches can have issues when backing up the configuration of your switch.
Although telnet is not the most elegant, nor the most efficient, way to obtain the configuration of a 3Com switch, there aren't many other practical options. By capturing the output of various display commands, CatTools provides a readable list of configured settings in case of switch failure.
Since 3Com does not provide a "show config" type command, the CatTools backup method is the next best thing. Because there are several commands required to obtain a complete list of settings, the backup of your 3Com switch can take up to five minutes per switch. A future version of CatTools may use SNMP or HTTP to obtain the config.
Occasionally, while accessing the 3Com switch CLI, the switch may perform a warm reset at odd times and for no obvious reason. This reset causes the telnet session to disconnect. All network traffic stops flowing until the switch has finished its start-up sequence which can take approximately 15 seconds. The switch appears to reset more often when the telnet session originates from a high speed port (100 MBps). Once the switch has warm started, it is more prone to crashing again. A power reset (removal of the power cord from the switch) does help to return the switch to a stable state and reduce the chance of a crash occurring.
The crash does not appear to be associated with any particular command and occurs with all versions of switch agent software, up to and including version 2.62.
Using an Admin user account to login instead of a Security user account reduces the occurrence of crashes.
Recommended backup plan
Since the chance of a switch crash, backup of the devices should only occur during times of low traffic use or after hours and you should reduce the frequency of your backups. Only make a backup when you believe the configuration has changed. Use the device Admin user account instead of the Security user account to login.
At this stage the config always appears to have changed. This is because various packet counters and stats are included in the captured config. These values change with each backup. A future version of CatTools may parse the captured data better and produce a cleaner list.
What commands are issued?
CatTools issues the following commands and captures the output to a file:
bridge multicastFiltering routerPort list
bridge port address list all
bridge port summary all
ethernet summary all
feature resilience detail
feature trunk summary
ip interface display
snmp trap display
system module display
system security access display
system security user display
bridge vlan summary all
bridge vlan detail
Defined VLAN numbers
bridge port detail
1 to number of switch ports
feature trunk detail
1 to number of trunks
When setting up your switch device, ensure that you enter the username and passwords for the device into the appropriate fields. Leave the VTY and enable passwords blank as they are not used for 3Com superstack switches. The standard 3Com usernames are:
You need to use the Security login if you want to make changes to passwords or user accounts.
Accessing switch stacks
A switch stack consists of up to four switches connected via matrix cables. Each switch has a unit number from 1 to 4 which identifies it. The IP address is the same for each device in the stack. Once logged in, you switch between the stack units by issuing the command
system unit N, where
N is the number of the stack unit you want to session to. For example,
system unit 3 switches to the third stack unit.
Refer to the 'Connecting via a session' section as to how to set up the devices in CatTools.
Sending commands to the CLI via CatTools
By using the Device.CLI.Send commands at enable prompt menu, you can send commands to the 3Com switch CLI. The registered version of CatTools allows you to capture the output to a file.
For example, to change the password for the user "admin" use the commands:
system security user modify admin
Another example of a CLI command is adding port 3 to VLAN 2 with tagging:
bridge vlan addport 2 3 802.1Q
To drop back a menu item, use the command