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IIS conflicting with two network adaptor

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I am running 2003 advanced server using IIS to host a site. I have two network cards installed. one card is used for IIS and has a static outside ip address. The other card is assigned an ip address but is the local area connection with in the local network. If I have the local connection disabled guests can access the site no problem. As son as i enable the local area connection, guests no longer have access. They get the error page can not be found.

I have the web site properties set to the correct static ip address of the outside connection. Any ideas on what may be causing this?

Topic

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In reply to IIS conflicting with two network adaptor

first question, why two nics on a web server?
If you have a public web server on a local network, hope you have really good security measures in place.

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Reply To: IIS conflicting with two network adaptor

In reply to IIS conflicting with two network adaptor

Please assign the ip address on the IIS.

Start –> run –> inetmgr
Drill down to “server name” –> Web Sites –> Web Site’s name (Or Default Web Site)
Go to properties (right click –> properties)
Under “Web Site” general tab, there is a section “Web site identification”. In that section, find the “IP address” and the pull down menu that should say “(All Unassigned)”. Change that field to the public ip address.

Cheers.

Reply To: IIS conflicting with two network adaptor

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Poster rated this answer.

anything beyond this?

In reply to Reply To: IIS conflicting with two network adaptor

My situation is very similiar. The web site is hosted on a dedicated line, seperated from our network. I have the web server connected to both networks.

When I disable the local network, the site runs fine. When enabled, it can’t be accessed from the outside.

The site is running behind a low end firewall/router. DHCP is disabled, and all appropriate ports are being forwarded to the internal web server address 10.10.10.10.

I know the forwarding and router config is good b/c it works on it’s own.

Any help would be appreciated, I’m stuck working this fine holiday weekend until I find and answer.

Thanks,

JD

Reply To: IIS conflicting with two network adaptor

In reply to IIS conflicting with two network adaptor

Did you ever solve this issue? I have the same problem and am just now starting to troubleshoot it. Any info would be appreciated.

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Figured it out once after a little bit of troubleshooting.

Workaround

In reply to Reply To: IIS conflicting with two network adaptor

What I have found regarding this situation is that Windows wants to communicate across 1 NIC period. It will accept connections from others, however, but It wants to have one as “Master.” The one its wants to lock on to is the one that gives it Internet access. If your LAN has internet access it will use the one for the IIS, as soon as it is accessed by the LAN it will “stick” to the LAN NIC and forget about the NIC connected to IIS. You can verify that this is happening because you can access a network share on the server and open a web page on the server.

The trick is to make windows use the NIC mapped to the external IP as “master”. This is do-able in 2 ways. The Hard way is to adjust the I/O adresses of the NICs so that the External IP one is enumerated first in the bios. The easier way is to physically swap the ethernet cables between NICs and swap the IP addresses.

This has the following effect: The first NIC loaded into BIOS, which windows prefers, is dedicated to communication through the external IP(IIS)for internet and LAN. Windows will use this until it gets a request from the 2nd NIC (a network share for example), at which point it will process the request then return network access to the Primary NIC.

Solution?

In reply to IIS conflicting with two network adaptor

I’ve just encountered the same problem on a number of our 2003 servers and am in desperate need of a fix. Did you ever get this resolved?

[Author]

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