Interfaces Config

on Ubanu 9.1

I am having issues with the configuration in my interfaces file. I have a block of 5 ip addresses (6 with the gateway) on network 173.*.*.200. I am using 173.*.*.201 as the ip address for my router connected to my cable modem. I have a Ubantu 9.1 server connected to one of the other 3 availble switchports of the cable modem with an ip address of 173.*.*.206 and apache2 webserver running.

I am able to ping the static ip address of the webserver, access the webserver via DNS and connect to the ftp server (all the same ip address) from any PC connected to my LAN, even with eth0 disconnected, without issues. With eth0 connected, I can ping WAN address, i.e. 4.2.2.2, without problems. However, no EXTERNAL users can connect to my webserver or even get a ping response. If I disconnect eth0 (the LAN interface) and try to ping 4.2.2.2 from the server, I get no response! I have even tried changing the configuration so eth0 is configured as the WAN interface with the same results.

The server is a Supermicro Dual Xeon 2.2G w/1GB memory, dual 10/100 NICs.

Here is the interfaces config.

auto eth0
iface eth0 inet static
        address 10.10.11.4
        netmask 255.255.255.224
        network 10.10.11.0
        broadcast 10.10.11.31
        gateway 10.10.11.1
        dns-nameservers 4.2.2.2
 
auto eth1
iface eth0 inet static
        address 173.*.*.205
        netmask 255.255.255.248
        network 173.*.*.200
        broadcast 173.*.*.207
        gateway 173.*.*.206
        dns-nameservers 68.87.85.98

What am I missing?

John