TOPIC: Whats 0.0.0.0?

Hi,

when running netstat on Windows I see that the following IP address is used: 0.0.0.0
Some TCP and UDP ports are open on it. I've read somewhere that it has to do with DHCP, but why is it listed there and why are there ports open on it?

Thanx in advance for any reply!

I believe that is your default gateway (router or firewall).

If you do a route print you will also see it:

C:WINNTsystem32>route print
===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x2 ...44 45 53 54 42 00 ...... NOC Extranet Access Adapter
0x1000004 ...00 02 b3 5c ec 0a ...... Intel(R) PRO/100+ Management Adapter
===========================================================================
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 192.168.35.1 192.168.35.7 1
127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1
192.168.35.0 255.255.255.0 192.168.35.7 192.168.35.7 1
192.168.35.7 255.255.255.255 127.0.0.1 127.0.0.1 1
192.168.35.255 255.255.255.255 192.168.35.7 192.168.35.7 1
224.0.0.0 224.0.0.0 192.168.35.7 192.168.35.7 1
255.255.255.255 255.255.255.255 192.168.35.7 2 1
Default Gateway: 192.168.35.1
===========================================================================
Persistent Routes:
None

Tom.

Well, i thought 0.0.0.0 was the default route for the CISCO routers ...

Tom can u please explain a li'l bit more on that route print command and wht does it do .

Well, that could be. But 0.0.0.0, or any address, has nothing to do with a particular device. It is just an address. 0.0.0.0 just tells you where your default (if it can't go anywhere else) route is (could be a cisco router, linksys router, Sonicwall router, linux box used as a router).

Route print (on a Windows machine) will tell you all the routes that that machine knows about. This is set up when you set your networking. The 0.0.0.0 address is the address you will get if you added a default gateway in your TCP/IP setup screen. If you left that field blank - you would have no 0.0.0.0 line.

To get a thorough explanation of the different columns look at:
http://support.microsoft.com/default.aspx?scid=http://support.microsoft.com:80/support/KB/ARTICLES/Q114/7/09.asp&NoWebContent=1

Tom.

Thanx tfs for your explanation!

However I fail to understand what Visual Basic has to do with gateways (based upon the link you posted).

Sorry for getting back so late on this. Been out of town.

You're right! I have no idea where that link came from. I know I checked it out before pasting it in. Maybe a Brain Fade!!! Wouldn't be the first and won't be the last, I suspect.

Anyway, try this link. This was the one I meant to send anyway.

support.microsoft.com/default.aspx?scid=kb;EN-US;140859

Let me know if it doesn't work for you.

Tom.