I've got one DHCP server on my router with one range of IP addresses.
I've got another DHCP server on my Vigor 130 modem with a different range of IP addresses.
Is this a good option for trouble free networking?

Depends on your network configuration. I'd assume the 130 was directly connected to a WAN port on your router and not into your main LAN, and thus the two DHCP servers will be on different, non-connected networks.

mbames wrote: Depends on your network configuration. I'd assume the 130 was directly connected to a WAN port on your router and not into your main LAN, and thus the two DHCP servers will be on different, non-connected networks.

Thanks for that explanation. The connections between the router and modem are as you describe.

If my router network facilities and settings are controlling the DNS server and firewall of the devices on my LAN, what is the separate modem network with DHCP server and firewall doing?
Does it stand in parallel with the router network, or does it stand in between the Internet and the router, as extra protection?

I'm reading about the subject from as many sources as I can find but still struggling to understand.

The Vigor 130's DHCP server isn't doing much; it will provide an IP address to a connected client when necessary but once the connection is up, PPPoE is used to bridge across so the DHCP server isn't doing anything.. Leave it alone