Port numbers for TCP,UDP,ARP,RARP ???

Unanswered Question
Jun 30th, 2003

Well we all know that port numbers are used to identify the protocols to identify the protocol to which the segment has to be handed over. For example TCP & UDP port numbers are 6 & 17(hex). Can some one tell if the same port numbers can be used to identify the application port & Can I get the port numbers for other protocols such as ARP, RARP.....



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Anonymous (not verified) Mon, 06/30/2003 - 08:06

TCP & UDP 6 & 17 are NOT port numbers but protocol numbers which is different! You are confused about the terms.

Protocol number is the end of the IP header (Layer 3 info) while Port numbers are at the beginning of the segment header (Layer 4 info).

Igrp, Eigrp, Ospf rely on ip for packet delivery and have their own protocol numbers and NO port numbers.

BGP and RIP use TCP & UDP on ports 179 & 520 and have no specific protocol numbers.

Hope this helps...

rmcardle3 Wed, 07/02/2003 - 19:54

Good question, jjasrotia and even greater answer, mcmarcos and dynamite assist, scappli.

I just have one question for the asker, jjasrotia.

Why has this answer not been rated?

Did you not ,get the answer you were hoping you would get. Sounds like you got the right one, to me. Please, the best way for your question to make a contribution is if you acknowledge when you have been helped. If you have not...say soooo.

Best regards,



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