2 network adapter cards, can ping internal but not external

[izzy777]

hello all

I have 2 network adapter cards in a "Win2K Server" installed machine (Dell Precision). One adapter came with the machine and I added the second adapter. Both adapters were configured accordingly - one with internal IP and the other with external IP with Gateway as my router.
From laptop inside network, I can ping internal adapter but not external adapter. From router I can ping external adpater but not internal adapter.

It's obviously something on the machine that is not right. Has anyone come across this and knows of any solutions?

Thanks a mil in advance!

 

[izzy777]

Sorry I should have mentioned - I want to be able to ping my router. And I enabled IP routing in Win2K (which is done in the registry)....

Thanks
izzy777

 

[zwardle]

I have done this configuration before and had no problems. I would trace the route the laptop is trying to use to get to the external IP. It is possible that when you ping the external IP, the ping is going to the router and the router is actually not configured properly to allow the trafic to go out and back in. I have seen this on several networks with Cisco routers.

Also, you may want to see the Mircosoft KB article 157025 for more information about configuration for multihomed computers.

 

[izzy777]

thanks zwardle, but I have done a tracert, and it can ping the internal Ip of the internal card from the laptop, but times out after that, so it does not get to the external network adapter card?

The router I am using is a Windows 2K server - RRAS, which is configured with 2 network cards as well. One card for my FW box at one location and the other for the other FW box at the other location.

 

[John Lewis]

Does your laptop have the default gateway set to the W2K server?

Doesn't really have to be set as the default route, but that sounds like what you want -- all traffic not for the internal network routed throught the W2K and on to the internet.

Also, are the two adapters on separate network addresses? You infer that they are, but it's not real clear.

 

[izzy777]

hi mhkwood, my two adapters are on separate network addresses.
The internal is on private addresses and external on public addresses assigned by the ISP.

My laptop's default gateway is the IP of the internal card of the Win2K server, which will eventually have my FW installed. The external card of the same win2k box has it's default gw as the ISP's router.

 

[John Lewis]

Doh! You didn't mention NAT on the W2K server. You need to install it to translate your private IP on the laptop to the public IP of the server. The router with the public IP doesn't know what to do with your private address.

http://support.microsoft.com/default.aspx?scid=kb;en-us;299801&Product=win2000

You've already got a lot of the first steps done.

 

[izzy777]

So with that said, does this mean that in it's simpliest form....................

I have 2 network cards setup on the machine (whose NAT will eventually be handled by my FW software), I should not be able to ping the external facing network adapter card from my internal LAN laptop?????? that's the expected results?

I am assuming that without any NAT I can ping the external card's IP from my internal laptop?

 

[John Lewis]

Actually, you should be able to get a ping to the external if of the W2K box. Sounds like you have the laptop correct, for some reason RRAS isn't firing up on the W2K box.

Open the KB article I posted. Go to step 2, that should tell you if RRAS is going and if all is OK. If not, you can fix it there.

Also, you might try 'tracert xxx.xxx.xxx.xxx' using the external IP of the W2K. You should see it hit the internal ip of the W2K if the laptop is doing what is expected.

 

[izzy777]

I enabled IP routing in the registry (for win2k)...I know in NT4, all you do is tick the -IP forwading for network card.... does RRAS have to be running? for internal card to talk to external card. I assumed that only "IPEnableRouting" in registry is to 1.

I did a tracert from laptop to external card and it hits the internal but times out after that...

 

[John Lewis]

Really sounds like the W2K machine isn't doing the forwarding. Make sure you have the key in the correct place, should be under HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

Also, did you restart after you made the change? Not 100% shure it's required, but never hurts.

If that doesn't work, I would really go for the RRAS wizard. It will probably point out what is wrong without digging a lot.

 

[izzy777]

Thanks, I triple-checked that key is in correct place, and I did restart, just to be sure....

 

[RichieClarke]

Might want to try looking at your routing table and your gateway settings on your NIC's (on all machines). Default gateway should only be set on one NIC on W2K Machine. From a command promt type "route print" (without quotes) and post results here.

Cheers,

Richie.

 

[phemt]

I had a similar issue when I installed a second network card and had two in at the same time.

I finally had to call in the hired guns to resolve this issue. The gun was confused for 3 hours and could not figure out the solution. He took the computer home and finally diagnosed the issue. Bcastner called it correctly stating it was winsock related.

When I plugged in both network cards at the same time, win2K got confused and thought it could fix the problem and corrupted the winsock registries.

He found the following Microsoft knowledge base

http://support.microsoft.com/default.aspx?scid=kb;en-us...

http://support.microsoft.com/default.aspx?scid=kb;en-us...

Although the error messages are different, the fix is the same.

Hope it helps, William