I have a ZyXel ES-2024 PWD switch. I would like a computer plugged into port 26 to see all traffic that passes through port 2, both inbound and outbound.
I have configured port mirroring for the appropriate port for both ingress and egress traffic as per the manual. However, when viewing the packets in Wireshark, I appear to see all packets TWICE.
I suspect this is related to traffic flowing around the switch and research on the internet shows some similar problems occuring with SPAN ports, but I am unable to find a definitive answer.
I have tried filtering to ingress or egress traffic; I still see double the respective packets.
Has anyone experienced similar trouble with this or another switch who could possibly point me in the right direction. Many thanks in advance.