Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I am using WireShark to analyse millions of packets. Is there a filter which will only show those packets which have errors?

By "error", I mean an IP error (e.g. incorrect IP header checksum), an TCP error (e.g. incorrect TCP checksum), or an error at the application layer (in my case, the FIX protocol, which is parsed by WireShark).

How can I configure WireShark to only show erroneous packets?

share|improve this question
add comment

1 Answer 1

up vote 1 down vote accepted

The only notion Wireshark has of "error" as a generic concept is the notion of "expert info" items with a severity level of "error" (which is the highest level of severity).

To find all packets with that type of "expert info" item, use the display filter

expert.severity == error

However, that will only show errors if the Wireshark dissector for the protocol where there's the error has code that looks for the error in question and, if it finds it, adds an expert info item for that error. (Wireshark is a dumb piece of software, not a clever networking expert that can detect errors other than the ones it's been written to detect.)

share|improve this answer
Your paragraph "However.." is misplaced given you're addressing somebody that uses Wireshark - (probably not an ignoramous), and it's also misleading because it suggests wireshark is too limited to specifically do what the questioner suggested, but if anybody here knows the Math to do those checksums and can make a filter out of it then Wireshark could do it. –  barlop Aug 7 '13 at 7:48
One might not be an ignoramus and still not realize that it will not necessarily catch arbitrary errors in the FIX protocol - errors that might not involve checksums (BTW, given that checksums depend on the packet data, and that you can't perform arbitrary calculations in a packet filter, you can't write your own filter to check checksums; fortunately, you don't have to, as that's a case where Wireshark does do the calculation and check the checksum for you). –  Guy Harris Aug 7 '13 at 22:45
add comment

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.