ipsrvtrace

[Steve Bellovin <smb () research att com>]

Quite a number of people have been asking me about ipsrvtrace.  It's a 
tool I wrote a few months ago, to investigate a service-specific black 
hole.  (Packets to one net to port 80 didn't get through; packets to 
other ports or other nets did, and the network manager insisted that 
there were no firewalls or transparent proxies in the way.)

Anyway -- the code is not (yet) released.  It runs on NetBSD, FreeBSD, 
and OpenBSD; a variant runs on Linux, but I haven't folded the Linux 
changes back into the base version yet.  If you need that sort of 
functionality today, use tcptraceroute, which you can find at
http://michael.toren.net/tcptraceroute

                --Steve Bellovin, http://www.research.att.com/~smb
                Full text of "Firewalls" book now at http://www.wilyhacker.com