how loopback address works ?

r u using a Engineering Operational Sequencing System?  (EOSS)

Thats the registered proggy that runs on that port...

I do not know ? Please, how could I know ?
My english is weak. What is proggy ? Thanks.

proggy= program

EOSS is a program used mainly by the goverment(navy) i believe...

t's the security component of Mozilla used by the password manager.
People will sometimes get upset when their firewall tosses an alert that
Mozilla/FF is accessing the local network.  It's totally harmless.

What version of FireFox are you running?  

If this helps, the function of loopback is for internal (127.0.0.1) debugging of the machine itself, just the one it is resident on, not to be sent as a packet to any other machine. Consider a program on your machine having a problem accessing a server, but it does not have a networking card installed. The loopback process can help determine the point of failure. Without a networking card, it may not be a problem with a remoate server. I would not like to think it would require any form of regular, consistent use, unless some debugging agent is also involved as a live tool. Once the computer is on, and a networking condition validated, I can't think of a good reason to test it again and again and again. It is unlikely one would remove the card (NIC) while the machine is still on. So in that sense I agree with a quote from eggm4n >  "It's totally harmless"

Talking to yourself, without opening your mouth = like a loopback
If no one else is around, then talking to yourself out loud, and listening in on the conversation of what you have to say .... maybe that is more like a loopback condition, proving you can talk and listen, but not proving much about how well communication is going, or whether anyone else would ever understand you (connect)

Thanks for helps,
-  The version of fireFox is 1.0.4  -
I understood that it is totally harmless, good!!!
But I  didn't realize the  necessity or how it would work.
You said :  t's the security component of Mozilla used by the password manager.
Could you explain/exemplify this affirmation ?
The IE keeps a udp port  on loopbak address 127.0.0.0: x           any : any
Someone knows why ?
Thanks

The "listening" socket does not accept connections, and even if it did, it is only bound to the loopback device.  The other loopback socket is connected to the "listening" socket.  The "listening" socket cannot be seen from the internet.

The mozilla networking code (necko) creates this loopback socket pair to be used in a loop that blocks on select.  By writing a byte to this socket, we can unblock the select call and cause some work to be done.  This is all part of the inner implementation details of necko.  I'mpositive that there is no security threat here.

Personal firewalls unfortunately complain about this loopback socket pair, and still other personal firewalls prevent it from being created.  In such cases, necko falls back to periodically calling select.

It is a shame that windows doesn't support selecting on an anonymous pipe.  That's what we use on other platforms.  As a result, you should not see this loopback socket appear in netstat on any other platform.

The alternative for necko would be to setup a WIN32 event loop and use WINSOCK asynchronous socket I/O, but our current approach has the advantage of being nearly cross-platform.  At least the code in necko is entirely cross-platform.  

Well, that helps me understand necko a little bit, I'll leave it to you and ask that you not ask me to try to repeat it just yet, (letting it sink in)

> The IE keeps a udp port  on loopbak address 127.0.0.0

Accept that my memory is weak on this, but I think it remains that 127.0.0.1 is your computer, itself, and Microsoft is among many who refuse to go along with standards. I could try a google to impress you, but it seems you know about enough already. Address x.x.x.255 is general broadcast, and x.x.x.0 is the LAN. Unique devices then must be addressed as ranging from x.x.x.1 to x.x.x.254 then. As time goes on, people give up on quibbling, and just try to use whatever they can get to work. So I think the results are essentially the same, for 127.0.0.x, MS is then looping back on the LAN inside your PC. (huh?)

Possibly this could be related to what part of the stack it is looking at, for using one or the other, and if you aren't using a stack according to 'standards" then, I revert to I dunno. The ones I like better are all those that are listed as being 0.0.0.0 (huh?)

Thanks for helps, but
very sorry,  I do not understand this  : "The mozilla networking code  creates this loopback socket pair to be used in a loop that blocks on select.By writing a byte to this socket, we can unblock the select call and cause some work to be done." And I think this is the core of the question.
And remember please, my english is weak. I spent much time discovering what means dunno (do not know).
Thanks again.

Do you really need to fine tune techno mumbo jumbo? My guess is that its relevance is key to the password-securing theme (from remote access). The resolution suggested is to get any personal firewall to quit interfering with any 127 dot address it has no business with, if it takes improving the firewall by upgrading it to hardware from software, if that's what it takes. But I have to defer to others concerning actual browser implementations (eggm4n?).

Yes, I really have to know this mumbo jumbo.
Thanks.

ok, but after all that, only a 'B' and no split?