tcpdump mailing list archives
Re: tcp sequence and ack number with libpcap
From: Andrej van der Zee <andrejvanderzee () gmail com>
Date: Fri, 20 Aug 2010 06:54:53 +0900
Hi, If I get "bad cksum 0 (->4327)!" for packets with "tcpdump -vv" like below, do I have to take special measures to read fields like seq and ack from the TCP header? 17:55:47.657974 IP (tos 0x0, ttl 128, id 13151, offset 0, flags [DF], proto TCP (6), length 1420, bad cksum 0 (->4327)!) 172.16.123.4.80 > 193.34.150.174.38357: Flags [.], seq 1:1369, ack 436, win 65100, options [nop,nop,TS val 53409804 ecr 3029480193], length 1368 Thank you, Andrej - This is the tcpdump-workers list. Visit https://cod.sandelman.ca/ to unsubscribe.
Current thread:
- Re: tcp sequence and ack number with libpcap, (continued)
- Re: tcp sequence and ack number with libpcap Eloy Paris (Aug 19)
- Re: tcp sequence and ack number with libpcap ronnie sahlberg (Aug 19)
- Re: tcp sequence and ack number with libpcap Andrej van der Zee (Aug 19)
- Re: tcp sequence and ack number with libpcap Andrej van der Zee (Aug 19)
- Re: tcp sequence and ack number with libpcap ronnie sahlberg (Aug 19)
- Re: tcp sequence and ack number with libpcap ronnie sahlberg (Aug 19)
- Re: tcp sequence and ack number with libpcap Andrej van der Zee (Aug 19)
- Re: tcp sequence and ack number with libpcap Gert Doering (Aug 19)
- Re: tcp sequence and ack number with libpcap Andrej van der Zee (Aug 19)
- Re: tcp sequence and ack number with libpcap Andrej van der Zee (Aug 19)