Firewall network configuration

[Steve Doerr <sdoerr@swbell.net>]

Hi.  This question is for a firewall and I wonder if anybody has any
advice on network configuration, because I can't get eth1 to pass the
internet connection to my hub.

I've got box1's eth0 connected to my dsl line through the dsl
modem/router and it picks up the ip, etc. through dhcpcd.  This card is
connected to the internet fine.

I've got box1's eth1 connected to jack 1 of the hub, but the hub doesn't
show anything connected.  eth1 is a good card, and I can ping it at
192.168.1.1, but I've missed something about configuring it to forward
the external connection out to my hub and on to my network.  I do have
ipmasq installed, but from what I've read, the defaults should handle
this if the network is configured correctly.

eth1 on box1 is configured as follows in /etc/network/interfaces (even
though I'm using dhcpcd on eth0, the external ip is always the same, so
I'm using static on eth1):

iface eth1 inet static
   address 192.168.1.1
   netmask 255.255.255.0
   network 192.168.1.0
   broadcast 192.168.1.255
   gateway <ext_ip_from_eth0>

Does anyone know what I should check now?

Thanks very much for any input.
Steve