Ask Your Question
0

How to filter tcp connection finish (FIN) initiated by certain IP

asked 2021-08-27 05:35:26 +0000

For example, I have two host 1.1.1.1 and 2.2.2.2.

After capturing all traffic between them in certain time range, I would like to find all TCP connection finish initiated by 1.1.1.1 (i.e. 1.1.1.1 sent TCP FIN first in TCP connection termination)

edit retag flag offensive close merge delete

Comments

To be clear: do you want to distinguish between TCP connection termination initiation by 1.1.1.1 and 2.2.2.2?

Jaap gravatar imageJaap ( 2021-08-27 11:24:07 +0000 )edit

Do you want to specify the time range in the filter too?

BigFatCat gravatar imageBigFatCat ( 2021-08-27 17:54:57 +0000 )edit

2 Answers

Sort by ยป oldest newest most voted
1

answered 2021-08-27 15:37:58 +0000

Chuckc gravatar image

updated 2021-08-27 15:40:30 +0000

There is a field for this in the current development branch (3.5).

#13210: Feature request: improve the tcp.analysis filter so it can find active or passive TCP close

(ip.src == 1.1.1.1) && (tcp.connection.fin_active)

The fields added in the change do appear in a 3.5.0rc0 build available in the automated build section of the download site.
There may even be a 3.5.0 (not rc) release in the next few days.
Wireshark expected release dates: Roadmap

edit flag offensive delete link more

Comments

GREAT. I have to play it when it is released

BigFatCat gravatar imageBigFatCat ( 2021-08-27 17:52:57 +0000 )edit

Gerald wrote: I'm proud to announce the release of Wireshark 3.5.0.

So if you are brave use it instead of 3.4.8

hugo.vanderkooij gravatar imagehugo.vanderkooij ( 2021-08-28 01:30:56 +0000 )edit
0

answered 2021-08-27 07:59:21 +0000

grahamb gravatar image

Using the display filter:

(ip.src == 1.1.1.1) && (tcp.flags.fin == 1)
edit flag offensive delete link more

Comments

I didn't read the question properly and the comment from @Jaap highlighted the issue, in that the user wants the occurrences where the specified IP sent the first FIN in the stream. This is not possible in a display filter because it requires a relationship between packets.

By changing the filter to ip.addr == ... all FINs for that address will be displayed and by adding a column for the tcp stream index, by inspection those streams where the target IP sent the first FIN can be found.

grahamb gravatar imagegrahamb ( 2021-08-27 11:40:46 +0000 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

Stats

Asked: 2021-08-27 05:35:26 +0000

Seen: 2,964 times

Last updated: Aug 27 '21