TCP Traceroute by Peteris Krumins.
From the post:
Did you know you could traceroute over the TCP protocol?
The regular
tracerouteusually uses either ICMP or UDP protocols. Unfortunately firewalls and routers often block the ICMP protocol completely or disallow the ICMP echo requests (ping requests), and/or block various UDP ports.However you’d rarely have firewalls and routers drop TCP protocol on port 80 because it’s the web’s port.
Check this out. Let’s try to traceroute www.microsoft.com using ICMP protocol:
Certainly a way to document subjects along a TCP route.
Can you think of other reasons to use traceroute?