Router to work as a WiFi on the LAN rather from a WLAN

Hi all

I have a typical situation in my Internet and LAN setup. My ISP provides me with a direct LAN cable that I need to connect either into my PC or into the WiFi Router WLAN port. I also have a LAN that I need to connect to, so I have installed a separate LAN card for the internal LAN purposes. My two setups are below with their issues. I hope someone can suggest a middle grounds to have a LAN and a WiFi too.

Scenario 1:
The ISP cable goes into the WLAN port of the Router. Cables from the router goes into my PC network card 1 and to other PCs for LAN purposes. The PC cards are all configured to automatic IP. LAN / Internet / WiFi is now available. This works fine for a few days and then the internet stops working because there is a conflict of IP. The ISP expects IPs like and the one on the LAN / Router for my PC is

Scenario 2:
The ISP cable goes into network card 1 (internet sharing is enabled and automatic IP) with the ISP's expected IP Another cable goes from my PC's network card 2 (fixed IP into the regular LAN port of the same Router. Without any issues over the months the Internet works, the LAN works (other PCs have fixed IPs too, etc) but no Wifi :(

Can I have best of both the worlds in such a situation? I can't install a 3rd network card for sure as the slot on the mother board is limited.

Please advise

Thanks in advance


isp==>(wan)router-->PC card-1, et al  (conflict 123.237, v

ISP===->pc card-1
        pc card-2==>router
  1. scenario-1 is a configuration or firmware condition
  2. scenario-2 is a real security issue and the primary PC is basically acting as a DMZ server and is at risk.
Here's my setup:
isp==(wan)router-1--- PCs in the same room
           +---(lan)router-2(with wifi) - - - wifi connections in the den
configuration to make this work with full file/print sharing:
  • disable DHCP in this router
  • setup all WiFi settings here
  • notice: router-2 wan slot is left empty to make this work
  • set LAN address of router one as you please (eg: )
  • set an address reservation for router-2's MAC -> a fixed, constant IP address on that same subnet (eg
  • set the DHCP range small (eg 2-32)
router-1 will control all auto-ip assignments for both routers.

Personally, I add another tweak;
  • reserve ip addresses for all of my devices into the low-end of the dhcp range (say 2-10) and
  • let 'guests' take addresses above 10
This gives the opportunity to allow file/print sharing to known systems (2-10) and disallow for the guests.

Setup totally within the routers allow my laptop to travel and not be effected by these choices.
Thanks a lot jobeard! I guess I will go for your suggestion of having a second router which does the WiFi and LAN whereas the present router only does WAN.

Kind regards