Copy from: https://www.google.com.tw/search?hl=zh-TW&client=ubuntu&hs=7P7&channel=cs&q=3com+switch+3226+mirroring&oq=3com+switch+3226+mirroring&gs_l=serp.3…17607.21669.0.21908.10.10.0.0.0.0.71.4188.8.131.52…0.0.1Hq7AKu1-HU
If you have 3Com Network Switch 3226 Model, and you would like to monitor your network, it does provide port mirroring feature. In order to enable it, you can login to the console via telnet, then execute commands accordingly to the screenshot below –
feature -> rovingAnalysis -> add|remove|start|stop|summary
3Com uses Roving Analysis as the term for the port mirroring, you will have to specify monitor port and analyzer port. Monitor port is the port you will want to monitor and analyzer port is the port to mirror traffic on monitor port. From my example I will monitor port 1 and its network traffic will be mirrored to the analyzer port which is port 25. Once I start monitoring, you can view the summary where roving analysis is enabled.
By now you can just plug in your IDS sensor or traffic collector to port 25 of the switch and start your network security monitoring.
P/S: I by no mean promoting or selling 3Com product, this is just to help in case one has the same device or as my own reference.