I currently run Slack-64 13 as a small server, router, gateway on a network. eth0 -> internet and eth1 -> internal switch. One of the services it provides is DHCP/DNS providing all the name resolution for the internal network, and bypassing my ISPs DNS for lookups. All the internal machines use DHCP and this server for their DNS server and also the Gateway address.

I now want to "inject" SmoothWall between the server, and the internet, so that SmoothWall has eth0 -> internet and eth1 -> internal switch. At this point, the server would only use a single interface eth0 -> internal switch.

I know I have to update the information that DHCP gives out, so that the DNS server still points to this machine, but the Gateway address is now the SmoothWall.

Is that sufficient, or am I missing something. Will bind, on the server, use the Gateway to route lookups, or do I have to explicitly tell it to go via that host/IP, and if so, how is that achieved.

Cheers.

Bind will be fine, it has no idea how it routes to anywhere, not it's business. Everything else sounds fine. You might want to move DHCP and DNS over to the Smoothwall box too though.

If this a paid-for SmoothWall instance or just the Express version? if it's free, you might want to consider ipcop instead which does about as much as the paid version of Smoothwall for no money.

It's the Express version. I'll take a another look at ipcop, as I thought there was a reason I eliminated that from my short list. But I can't remember why now. Damn, old age sucks.
The Express version doesn't support updating my internal DNS automatically when DHCP leases are handed out, that I could see, which is why I was leaving on my existing server.

Cheers.