Basic filteringĪs I said, in really old Wireshark versions, the filter box did not yet help with finding the correct filter, so it often took quite some time to get the filter expression right. We don’t even need the excellent “Wireshark Display Filter” cheat sheets from anymore (well, Jeremy still has a lot of other, really helpful cheat sheets, so check them out). You can filter on almost anything in a packet, and ever since the filter box started suggesting possible filter expressions it got really easy to find the one you wanted. Yes! There is nothing better than one to really understand.Wireshark has a lot of display filters, and the filtering engine is really powerful. After the filter was applied, all packets related to that transaction were filtered and it was possible to the application response times. At the time it was the number identifying the customer.

udp contains “string” or tcp contains “texto” : by now you already know…Īrmed with the knowledge of these filters, all that was needed was some kind of reference.

ip contains “string”: searches for the string in the content of any IP packet, regardless of the transport protocol.

frame contains “string”: searches for a string in all the frame content, independently of being IP, IPv6, UDP, TCP or any other protocol above layer 2.

The “contains” operator can be used to find text strings or hexadecimal characters directly with the name of the protocol instead of specific filters like http.host or.

In the middle of so many transactions and a working store, how to find the TCP conection that has the transaction to troubleshoot? The solution

The application was developed in-house, didn’t use any of the known application protocols like HTTP or FTP and wasn’t encrypted. Recently, I had to look at a problem of a sales application where users reported that “the network was slow”.

While most people think of it at the end of the fight, with me it’s always on top of the list. Wireshark is my tool of choice for troubleshooting.

Wireshark command line display filter