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Deciphering TCPDUMP

Posted on 1998-11-14
Medium Priority
Last Modified: 2013-12-26
Can someone give me a site that breaks down the output of TCPDUMP? Here is a sample output that i cant figure out:

21:52:32.058766 d196-tanna.net.1023 > praise.com.http: S 432195:432211(16) win 10052
21:52:32.228766 d196-tanna.net.1025 > ns1.tanna.net.domain: 39598+ (42)
21:52:32.658766 ns1.tanna.net.domain > d196-tanna.net.1025: 39598* 1/3/3 (203) (DF)
21:52:32.658766 d196-tanna.net.1027 > ns1.tanna.net.domain: 39599+ (46)
21:52:32.918766 ns1.tanna.net.domain > d196-tanna.net.1027: 39599* 1/2/2 (187) (DF)
21:52:32.918766 d196-tanna.net.1028 > ns1.tanna.net.domain: 39600+ (45)
21:52:33.158766 ns1.tanna.net.domain > d196-tanna.net.1028: 39600* 1/2/2 (160) (DF)

I understand the first line in that it is sending a "S"YN request with a ISN (Initial Sequence #) of 432195 and it appears to be sending a data packet of 16 bytes in size with a window size of a little of 10k.  Besides that i have no idea what the rest is saying ie. "DF", "*", "1/2/2", ".", etc...

Is there a site that breaks down this information or is the best way just to play around with it?

Question by:aniston
1 Comment
LVL 51

Accepted Solution

ahoffmann earned 40 total points
ID: 1294152
looks like an DNS answer, (DF) means don't fragment IP (see man tcpdump)

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