Hello Kapil
TCPTraceroute works much the same way as traceroute does, only instead of using UDP, it uses TCP. The results of a TCPTraceroute are much the same as those of a regular traceroute, but because of the differences between TCP and UDP, the mechanisms differ slightly.
Specifically, TCPTraceroute will use what is called a TCP SYN scan, also called half-open scanning. It doesn’t open a full TCP connection with each hop along the path that is being traced, but it sends a SYN packet, as if it is going to open a real session. A SYN/ACK response indicates that the port is listening or open. When it receives a response, it considers it a successful probe, and then sends a packet with an RST flag to close the connection.
The output of a TCPTraceroute is virtually identical to that of a regular traceroute, as both actually do the same thing. But TCPTraceroute is useful for situations where UDP traffic would otherwise be blocked, such as through a firewall.
I hope this has been helpful!
Laz