FM Server on two IPs / Networks

[cello]

Hello everybody!

We have two servers:

- Server A runs FileMaker Server 5.5 on Mac OS X

- Server B runs a Terminal Server on Windows Server 2003

FileMaker Pro 6.0 is installed on the Terminal Server for the users.

Both servers have fix IPs (81...) so they can be accessed from the Internet. Up to now, users had to connect from their local computers using FileMaker Pro to FileMaker Server to use the databases. Now we'd like to migrate some of them to the Terminal Server.

We have linked the two servers using a gigabit-ethernet directly (both servers have two network-cards). This link uses internal IP-addresses (192.168.*.*). This way the traffic between the clients (on the terminal server) and the FileMaker server doesn't have to go through the router but directly from one server to the other -- at least it should do so.

When I'm running FileMaker Pro on the Terminal Server and enter the local IP as the host-address, FileMaker Pro connects to the Server using the (slower) external connection, using the external IP (81.***). WHY?

In the Preferences of FM Server one can choose a "preferred IP", which is currently set to the external IP. May this be a reason?

If FileMaker Pro connects using the internal IP, it should stay on that network interface... but seemingly it doesn't.

I tried changing this setting, resulting that external clients couldn't any longer connect to the database from the internet.

Has anyone an idea, what I can do so FileMaker Pro uses the internal Gigabit-link to access FMS?

Problems with the configuration of the network interfaces can be ruled out: Setting up a web server with the local IP on Server A and loading the page from Server B works correctly using the internal link.

TIA!

[Charlie Boisseau]

When FileMaker Server receives a connection on a non-default interface, it will prompt your computer to reconnect using the preferred IP. In your case, when you connect to the 192.168.x.x address while your server is set with the 81.x.x.x interface as default, the connection will succeed (albeit slowly) because both boxes have access to the externally accessible subnet (via their other NIC).

However, when you change the default interface to the internally routed 192.168.x.x interface, only your internal connection will work. It will not work for your internet clients because when the server tells them that they should *really* be connecting on the 192.168.x.x address, they will try to access that address, which of-course they can't.

To solve this problem, you could do one of two things:

The simplest method would be to buy a gigabit switch, and plug both the OS X and Windows servers into it (along with the connection to your existing network / internet connection). This would mean that you could get rid of the internal 192.168.x.x route all together and run both boxes via their routed 81.x.x.x addresses over the gigabit cards.

The alternative would be to setup a port forwarding rule on the Mac OS X server using the built in firewall (ipfw). An example ipfw setup might be:

sudo ipfw add 192.168.x.x,5003 tcp from any to 81.x.x.x 5003 in

This should direct all traffic on port 5003 (FileMaker) from the internal interface to the routed one. As far as the server is concerned, it is only receiving connections on the external interface, when in act it is receiving connections on the faster 192.168.x.x interface. It shouldn't slow down or try to switch to the external interface manually. Be sure to have the FileMaker server's default interface set to the 81.x.x.x interface. You can test it by unplugging the slow network card on the PC and see if the connection still succeeds.

[cello]

CharlieB said:

The alternative would be to setup a port forwarding rule on the Mac OS X server using the built in firewall (ipfw). An example ipfw setup might be:

sudo ipfw add 192.168.x.x,5003 tcp from any to 81.x.x.x 5003 in

This should direct all traffic on port 5003 (FileMaker) from the internal interface to the routed one.

Thank you for your reply, especially the ipfw-code! I'll soon try it out, but:

This may only be half of the work I think: FM Server still tells the client to connect using the external IP. So I would have to do some equivalent on the client (=terminal server): tell the computer that every connection made to 81.x.x.x should be going through the internal NIC (192.168.x.x).

Does anybody know how to achieve this?

[cello]

I got the solution!!

I had to change the routing table on the terminal server: I added a new route, so that all traffic for the FM Server uses the internal IP of that server as gateway. Like this, the TS sent all traffic using the internal NIC, and the Mac-Server forwarded the traffic internally to the external IP, so FMS was happy - as am I ;-)

I didn't need to enter the port-forwarding rule in ipfw, it was done automatically by the OS.

Thanks for your help!