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looped ports

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5 replies

by m.sajjad.m

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Hi all,
I use a software (Active Ports by www.ntutility.com) to view the TCP/IP ports activity in my systems. I am looking that 127.0.0.1:x ---> 127.0.0.1:y connection and
127.0.0.1:y ---> 127.0.0.1:x connection in my all NT server computers. The over all functionality of servers is OK, but I am still worried about this looped ports action. Is it a bug, or internal function?

5 replies

by tech_wiz03

127.0.0.1 is the pc's loopback port and it is regularly active in some configurations to do handshaking. It can be used to pass network information sent from the console back to running programs either as a test of legit network responce or as a means of passing information internally between processes that don't have a preset method of talking to each other.

regards
rick

by m.sajjad.m

I use this software on my win2k pro & server also. But no such activity on these machines. What about that?

by tech_wiz03

Beleave me! 127.0.0.1 is the loopback. It never leaves the pc that it is on, never talks to network external to the pc. That IP address is specifically reserved for the purpose I just mentioned. NT servers must have a loopback port defined but microsoft removed that constraint on win2K and winXP. You can still set-up a loopback port on these other operating systems but now must do it manually.

If you still need convincing look it up under ip dotted quad standards and prerequistes, ip addressing fundamentals, network protocols and theory.

best regards
rick

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