I used Wireshark to control communication between PC and ATA when uploading configuration file via local network. PC with Ubuntu and ATA connected to small hub (blue WAN port <-> to hub). Ubuntu run ISC-DHCP Server with subnet configured for ATA, and config file is in TFTP root directory. As I can see, Wireshark does show that the device downloads it's profile successfully, but it never reboot to apply the new profile to the device. I tried few times, what can be the problem? There is also ETHERNET FRAME CHECK SEQUENCE INCORRECT entries, but not sure this can be an issue.
asked 21 Jan '17, 15:27
edited 21 Jan '17, 15:42
The Ethernet Frame Check Sequence is handled by the network adapter - it's unusual to see the actual FCS in a wired capture without certain equipment. Since it is handled by your adapter, you see all 0's for the value, while Wireshark is calculating the actual value, and of course it is failing the check. The preferences pain has the requisite entries to disable the validation:
Also google has a lot of information on this topic, much from previous questions related to FCS:
Most likely, you can ignore this error or turn off the check in Wireshark. An actual bad frame with a bad FCS would usually never make it up to Wireshark, so you wouldn't see it - you would need specific hardware configured to pass up bad frames, or see it in the various interface counters as dropped. If you have a managed switch, you likely have counters for this sort of thing. A basic unmanaged switch likely does not.
answered 22 Jan '17, 04:33