IP 0.0.0.0?

[H M]

sometimes one of my programs tries to access IP 0.0.0.0. is there some
special significance with this IP address? my firewall blocks those
attempts, and i haven't seen any negative effects so far...

[ArtP]

On Mon, 01 Sep 2003 18:52:27 +0100, H M >
wrote:

>sometimes one of my programs tries to access IP 0.0.0.0. is there some
>special significance with this IP address? my firewall blocks those
>attempts, and i haven't seen any negative effects so far...


Back when I was playing with that stuff, on some systems, that was an
alias for yourself.

[Ishrat Zahid]

An IP address 0.0.0.0 indicates a "default route", that means "match
anything" and forward
to the default gateway you have mentioned. This is useful when you have
only one exit point from
your network.

Ishrat

H M wrote:

> sometimes one of my programs tries to access IP 0.0.0.0. is there some
> special significance with this IP address? my firewall blocks those
> attempts, and i haven't seen any negative effects so far...
>

[Scott Lowrey]

"Ishrat Zahid" > wrote in message
...
> An IP address 0.0.0.0 indicates a "default route", that means "match
> anything" and forward
> to the default gateway you have mentioned. This is useful when you have
> only one exit point from
> your network.

That isn't quite correct. When 0.0.0.0 is used in an IP routing table as
the destination route, 0.0.0.0 is the default route.

When used as an IP address, 0.0.0.0 is equivalent to the loopback address
127.0.0.1. (Which is also equivalent to your local IP address.)

Unfortunately, my Windows 2000 box doesn't recognize 0.0.0.0 as the loop
back unless I tell it to. Unix boxes work as described.

If you're seeing 0.0.0.0 in an application, the application is probably not
configured correctly for network operations.

-Scott

-Scott