A popular application to capture data packets is Wireshark. It can be combined with the LAN Port Mirror function available in higher end in DrayTek routers to capture LAN packets, which can help support engineers analyse issues between a LAN host/server and the router.
1. Download and install Wireshark on a computer, then connect the computer to one of the router’s LAN ports.
2. Set up LAN Port Mirror. Go to LAN >> LAN Port Mirror:
- Select Enable
- Choose the Mirror Port as the one the computer running Wireshark is connected to.
- Choose Mirrored Tx Port and Mirror Rx Port as the LAN port to where the traffic you’d like to monitor is on.
3. Run Wireshark (as administrator), double-click the network Interface connected to the router.
4. You should see the packets from the other LAN port.
5. Wait until you see the packet you need, then click the stop button.
6. Save the file.
7. Disable LAN Port Mirror.