Snort mailing list archives
Re: simultaneous snort and tcpdump
From: Gary Flynn <flynngn () jmu edu>
Date: Fri, 20 Sep 2002 14:32:19 -0400
Bennett Todd wrote:
In testing, I've run both snort and tcpdump (and other libpcap based sniffing programs) concurrently against the same promisc interface, and even concurrently used that same interface for real network interaction. As far as I know, you can just run your snort and your tcpdump at the same time; while the performance consequences might not be ideal, I suspect they'd be better than one tcpdump teeing to a fifo for snort then piping into another tcpdump.
My experiences are the same as Bennett's. I've got ntop and snort running on the same interface and they seem to be sharing it fine. When I first contemplated doing this, I did some superficial research that suggested to me that this wouldn't be a problem. After diving through pcap code and then into the kernel network handling code, I came to the conclusion that all pcap applications have a PF_SOCKET open whose packet_rcv() functions are sequentially called by the kernel. This seems to be very nicely documented in the following two articles: http://www.linuxjournal.com/article.php?sid=4852 and http://www.linuxjournal.com/article.php?sid=5617 -- Gary Flynn Security Engineer - Technical Services James Madison University Please R.U.N.S.A.F.E. http://www.jmu.edu/computing/runsafe ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf _______________________________________________ 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:
- simultaneous snort and tcpdump Carl Gibbons (Sep 20)
- Re: simultaneous snort and tcpdump Bennett Todd (Sep 20)
- Re: simultaneous snort and tcpdump Gary Flynn (Sep 20)
- Re: simultaneous snort and tcpdump Carl Gibbons (Sep 21)
- Re: simultaneous snort and tcpdump Jason (Sep 22)
- Re: simultaneous snort and tcpdump Carl Gibbons (Sep 26)
- Re: simultaneous snort and tcpdump Bennett Todd (Sep 26)
- Re: simultaneous snort and tcpdump Carl Gibbons (Sep 26)
- Re: simultaneous snort and tcpdump Jason (Sep 26)
- Re: simultaneous snort and tcpdump Gary Flynn (Sep 20)
- Re: simultaneous snort and tcpdump Gary Flynn (Sep 26)
- Re: simultaneous snort and tcpdump Martin Roesch (Sep 26)
- Re: simultaneous snort and tcpdump Bennett Todd (Sep 20)