Snort mailing list archives
Re: TCP Flags & MySQL
From: Joel Esler <joel.esler () sourcefire com>
Date: Mon, 10 Apr 2006 11:32:17 -0400
TCP flags are in "decimal" value. So. 2 would be SYN, and 18 would be a combination of two flags, ACK = 16 and SYN = 2, so 18 = SYN, ACK.
The number in the tcp_win size is the "window size" of the packet. You can google all sorts of information concerning either of these topics.
You can write a BPF filter for Snort or tcpdump to look for these values (if you want to look at them in a dump format) with the bpf filter of 'port 0 and tcp[13] = 2 or tcp[13] = 18'.
It might be easier to install a GUI for the db, like BASE. That way you can "see" these alerts in your browser.
Joel Paul Melson wrote:
I have a Snort sensor logging to a MySQL database which is front-ended by a commercial application that allows for packet payload retrieval. This weekend, the system recorded a large number of "TCP port 0" alerts, and as expected it didn't record a payload. However, it did record tcp_flags and tcp_win. However, I am having difficulty interpreting the raw values in the tcphdr table into usable data. Can someone point me to a doc that explains these values, or if I tell you that the tcp_flags values I see most often are 2 and 18, can you tell me which flags are set? Thanks, PaulM ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ Snort-users mailing list Snort-users () lists sourceforge net Go to this URL to change user options or unsubscribe: https://lists.sourceforge.net/lists/listinfo/snort-users Snort-users list archive: http://www.geocrawler.com/redir-sf.php3?list=snort-users
------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ Snort-users mailing list Snort-users () lists sourceforge net Go to this URL to change user options or unsubscribe: https://lists.sourceforge.net/lists/listinfo/snort-users Snort-users list archive: http://www.geocrawler.com/redir-sf.php3?list=snort-users
Current thread:
- TCP Flags & MySQL Paul Melson (Apr 10)
- Re: TCP Flags & MySQL Joel Esler (Apr 10)
- RE: TCP Flags & MySQL Paul Melson (Apr 10)
- <Possible follow-ups>
- TCP Flags & MySQL Paul . Melson (May 10)
- Re: TCP Flags & MySQL Joel Esler (Apr 10)