Trying to set up DHCP network with Mac Pro

[Vinnievin]

Hi, I am working at an American School in Niamey, Niger. We recently received a new Mac Pro (nahalem 2009) with Mac Server X.5. I am trying to set it up on a network, and I am having a problem.

This network is originally configured through a Linux box. The idea is to replace it with the Mac Server and then reconfigure the Linux box with Windoze to run the Quickbooks DB. I will run the student labs off of netboot images from the mac server and set up file storage on two RAIDed 1TB hard drives.

I have configured en0 to the gateway and en1 for the LAN. I am able to get the server online, but as soon as I connect a network cable from en1 to a switch (or anything) I lose my connection to the outside world.

Does this hardware configuration require a network card in one of the PCIe slots to work? I feel like I am overlooking something ... checking NAT, Firewall, DHCP, DNS ...

 

[Lanbrown]

1) What is your firewall?
2) What is your DHCP server?
3) Have you checked your default gatway?

 

[Vinnievin]

more info

1) What is your firewall?
2) What is your DHCP server?
3) Have you checked your default gatway?

We have a dish with a router on the roof. It is 192.168.10.254 (supplied by the ISP) and the linux server's IP address is 192.168.10.102. The idea is that the firewall and the DHCP server would BE the Mac Pro, which is running mac server 10.5.7. It comes into the dish router and then straight into the Mac Pro (via en0 - ethernet 1). When I disconnect the linux server and configure the mac pro with the same information, I can ping the gateway and resolve IP addresses.

However, immediately after connecting an ethernet cable to the second port (en1 - ethernet 2), I can no longer ping the gateway. I can't browse. I can't do anything.

Do I need a PCIe network card? Is that what I need to have both a signal in and signal out?

 

[Vinnievin]

more info

1) What is your firewall?
2) What is your DHCP server?
3) Have you checked your default gatway?

We have a dish with a router on the roof. It is 192.168.10.254 (supplied by the ISP) and the linux server's IP address is 192.168.10.102. The idea is that the firewall and the DHCP server would BE the Mac Pro, which is running mac server 10.5.7. The internet currently comes into the dish router and then straight into the Linux server. When I disconnect the linux server and configure the mac pro with the same information (via en0 - ethernet 1), I can ping the gateway and resolve IP addresses.

However, immediately after connecting an ethernet cable to the second port (en1 - ethernet 2), I can no longer ping the gateway. I can't browse. I can't do anything.

Do I need a PCIe network card? Is that what I need to have both a signal in and signal out?