[Asterisk-Users] very OT - basic newbie networking question

[Asterisk]

Sorry to ask such a basic question:

I have a * box with 2 nics in the following setup:

Internet
|
192.168.5.253 (firewall)
|
192.168.5.xxx network (gw 192.168.5.253)
|
192.168.5.10 (* nic 1)
192.168.6.10 (* nic 2)
|
192.168.6.xxx network

The netmask for both networks is 255.255.255.0

The 192.168.6.xxx networks has a 48 port switch solely for the use of 
cicso 7940 phones, the 192.168.5.xxx is for the pc's (winxp) / servers 
(2003) etc.

I want to be able to access the phones (telnet/web etc) from the .5.xxx 
network, and I want the phones to be able to access the .5.xxx network.

I have tried various combinations, to no success - hence the plea for 
help. There is *too* much google for 2 nic networking !

So, finally to the question:

What do I need to do to achieve my goal ? would some kind soul supply 
m,e with the routing table and / or network settings that I need to apply ?

Many thanks.

Julian