I want to look at the communication between a Win7 box and a PLC device. They speak the Omron FINS protocol over ethernet. However, Wireshark 1.8.3 is only able to capture the responses of the PLC, not my requests. There aren't any problems with other protocols - they got captured correctly. The source PC is running Win7 x64 with Wireshark 1.8.3 64 bit and has a Broadcom 57xx Gbit NIC. Wireshark is started in promiscious mode without any filters. This PC is connected to an switch. The PLC device is also connected to this switch. We also tried to directly connect the PC to the PLC device with an ethernet cable - no change here. What may be the problem here? asked 02 Nov '12, 03:36  abachmann edited 02 Nov '12, 07:01 |
One Answer:
Sometime software firewalls can cause these symptoms, especially 3rd party ones, e.g. Norton. The standard Windows one has never caused me issues. If you do have 3rd party firewalls/anti-virus try disabling it. answered 02 Nov '12, 09:47  grahamb ♦ There is no 3rd party firewall installed and the Windows firewall is turned off. But there is Mcafee Antivirus installed, I will try disabling it. But why should it block only this traffic and no other packets like ARP or SMB? (02 Nov '12, 12:12) abachmann I have no idea, and this is purely anecdotal, but every machine I've ever had to look at for "issues" was improved by removing Mcafee or Norton if they were found to be infesting the machine. (02 Nov '12, 13:08) grahamb ♦ |
Please edit your question to describe your capture setup, i.e. where are you capturing etc.