MTR : TCP 443
mtr" (My Traceroute)
By default, the "mtr" (My Traceroute) command uses the ICMP version 4 protocol (Echo Request, Type 8) to probe the network. It relies on ICMP version 4 for return packets (Type 11: Time Exceeded).
The default ICMPv6 type sent by the mtr command (in ICMP mode) is Type 128 (Echo Request).
How ICMPv6 types work with "mtr" :
Type 128 (Echo Request) : The base type used to probe routers and the target.
Type 3, Code 0 (Time Exceeded) : Returned by intermediate routers when the Hop Limit reaches zero.
Type 129 (Echo Reply) : Returned by the final destination machine upon receiving the packet.
However, the "mtr" command can also use the TCP protocol (by sending SYN segments) if the --tcp option is explicitly enabled.
For example, the "mtr" command to probe an HTTPS web server is "mtr -T -p 443 <server_address>". This command uses the TCP protocol on port 443, which is the standard port for secure HTTPS connections.
Useful options :
-T : Uses TCP instead of the default ICMP or UDP.-p 443 : Specifies the destination port (443 for HTTPS).--report : Outputs a report after a fixed number of cycles.-c <number> : Sets the number of packets to send.More informations "mtr-command.txt".