tcp/udp version of traceroute

tcp/udp version of traceroute

Post by Roger Boo » Thu, 08 Jan 1998 04:00:00

Does anyone know if there is a program out for tcp/udp that performs
similarly to traceroute?

IE, you tell the program: tcptrace 25, it sends
out a tcp packet on the sendmail port with a ttl of 1, and looks
at the response, sends another with a ttl of 2, etc etc.  Traceroute
is rapidly losing its affectiveness as more and more firewalls block
much the upper UDP ports.

While this is a Unix newsgroup a version for 95 would be nice also, then
I could put it on a remote (geocities) site and when someone tells me
"your router is down, traceroute ends there" I could give them this program
so they could find that they were actually being blocked by a firewall
on their end.

The reply-to: address in the headers is a valid address, if you want
to send me e-mail just hit reply and it should work fine.  If your
newsreader is broken and can't deal with that then send your e-mail



1. ipchains/TCP/UDP, Why should I open UDP ports so that my TCP ports can work?


I have set up firewall to accept some ports.
/sbin/ipchains -F input
/sbin/ipchains -P input ACCEPT
/sbin/ipchains -A input -p TCP -s 0/0 --dport ssh -j ACCEPT
/sbin/ipchains -A input -p UDP -s 0/0 --dport ssh -j ACCEPT

Then I want to lock down all other ports.
/sbin/ipchains -A input -p TCP -s ! -j DENY

#??? what's wrong with this UDP ???
/sbin/ipchains -A input -p UDP -s ! -j DENY

If I comment out the UDP line, I can ssh into firewall from outside.
If I don't comment out that line, I can no longer ssh into firewall from

Why should I open UDP ports so that my TCP ports can work?

Thanks for any help.

Ed Wu

2. wu-ftpd & Slackware 3.1

3. traceroute w/ icmp and udp probes

4. BROTHER Laser Printer

5. tcp equivalent to mtr, as tcptraceroute is to traceroute

6. any one compiled LAPACK/LAPACK++ for linux?

7. Is there a version of traceroute in Linux that support source routing?

8. Automatically activate driver for Elo touchscreen monitor

9. traceroute version 960301 binary for Solaris?

10. /usr/sbin/traceroute ha1 ksh: /usr/sbin/traceroute: not found

11. FireWall-1 & High UDP/TCP ports

12. TCP and UDP window size

13. How do I find/get free TCP/UDP ports