Paris-traceroute result with TCP protocol

[Pruthviraj Jadeja]

Hello,

I want to know what is the reason behind giving "* * *" in Paris-traceroute TCP result. 

A possible reason is that the firewall might drop the packet or block it. But I have specifically updated the policy in the firewall and when I run the other protocols like traceroute with TCP or mtr with TCP protocol. Why does Paris-traceroute return only "* * *" , and also when I run Paris-traceroute with "-U" (UDP protocol) it successfully gives me results. Other commands do give commands with TCP protocol.

Results :

sudo Paris-traceroute -T -q 5 -p 443 -M 5 -s 11312 facebook.com
traceroute to facebook.com (157.240.16.35), 30 hops max, 42 bytes packets
 1  * * * * *
 2  * * * * *
 3  * * * * *
 4  * * * * *
 5  * * * * *

I want to understand the reason. Please help me out, it would be great. 

[Mando Мандо]

Hello

If I'm correct, the paris-traceroute in its TCP version never worked.

This is because in libparistraceroute, the TCP connection toward the target host is never opened. This is because libparistraceroute relies on raw socket. We use raw sockets because we use the IP checksum to encode the probe packet ID. Only raw sockets are currently supported. Raw sockets are perfectly fine to probe ICMP or UDP destinations, because there is no need to explicitly open a socket with the target host (contrary to TCP).

Adding TCP socket support would be a great addition. This would impose however to change the way we label packet probe, adapt socketpool.{h, c} and network.{h, c} as well as the measurement tools to explicitly rely on TCP sockets. This is a significant piece of work and that is why it hasn't been implemented.

If you are interested in developing these additions, I can provide guidance, code review, but at my level, I won't have time to implement anything.

Best regards