transport layer

Question

what happens when a host receives a TCP segment whose port number or source IP address do not match with any of the ongoing sockets in the host?

one of the answer i think is an ICMP destination unreachable message will be transmitted.

but could it be a possibility that the host will wait for a particular time period for the host to start listening to that port?(in case of no ongoing port of the number).

how the answer would change in case of UDP connection.

Comments

if source IP donot match

then what is use of waiting?

UDP is connectionless, so it could accept anything

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@srestha Ma'am

in the bracket i've explicitly ask the validity of that solution for PORT# not matching.

Answer 1

If a host receives a TCP segment where the port numbers or source address to not match any connection (e.g., the socket is closed or there is no listener on that address), it will send back a reset segment, a TCP segment with the RST flag set. In the case of UDP, an attempt to send a message to a port that does not have any process listening on it will result in the generation of an ICMP message back to the sender.

Source: https://www.cs.rutgers.edu/~pxk/352/exam/study-guide-2.html