|I've been asked to expand an existing network and need advice or pointers to tech articles on the best way to set up a dual network. |
The existing, working setup:-
Intelligent tills and telephone switchboard are connected to a couple of WinXPpro PCs via a basic newtwork switch. This equipment forms a fairly secure "back office" network separate from the "public" network. The public area has a public PC and wireless access point connected by the broadband router. In-between these networks, we have a PC with two network cards, one connected to the back-office network switch, and the second NIC connected via a hardware firewall to the broadband hub/router provided by the ISP. This PC is able to browse the back-office network and surf the net via broadband. So-far-so-good, this is the (undocumented) set-up I took over and it all works OK.
I now want to provide internet connectivity to another PC on the "back-office" network, I tried to imitate the setup of the working PC by fitting a second NIC card and a cable through to the firewall / BB router. Using this, the internet works OK so long as I disconnect the first NIC's patch cable to the "back-office" hub. Likewise I can only browse the "back-office" network while the second NIC patch cable to the BB firewall / router is unplugged (i also tried without the firewall but the same thing happened).
I suspect some sort of confict with DNS / DHCP services but can't find good quality info that applies, most articles are talking about windows internet connection sharing.
The set-up I inherited might not have been done the best way to start with. Any suggestions?
"Back-office" switch - NETGEAR FS605
"Firewall" Netgear FVS114 ProSafe™
"Public Hub" British Telecom 1800HG Wireless Home Hub ADSL Router