I have a TL-SG105E smart switch and I want to use it to sniff a network path. So, I am configuring one of 5 ports as a mirror port, so that it spits out everything received from other ports (in this scenario only 2 of them used in order to separate a path). I connect the mirror port to an additional network interface on my computer to capture everything by Wireshark. That works fine! Furthermore, I can access the web-server of the switch through this interface (192.168.*) to check the port statistics etc.

The only problem:

This switch forwards packets incoming from mirror port to the other ports i.e. it creates a connection between my second network interface (192.168.*) and the rest network i.e. path, which I am just trying to sniff. Is there an easy way to prohibit that? or do I need a special tap hardware for this use case? If I use the port-based VLAN in order to isolate the mirror port, mirroring stops working.

Regards & thanks to you!