Using two DHCP servers on LAN
Posted on 2010-11-29
I am using a broadband wireless as my backup internet connection, my primary is using ADSL with a PIX 506 firewall. My ISP recommend me to use Ericsson W30 or W35 broadband router for the WIFI internet, and this Ericsson W30 or W35 come with DHCP server feature. I am currently using my Windows DC as DHCP server, therefore all LAN user get the IPs from this Windows DHCP server.
Because the Ericsson W30 or W35 will be used as a wireless internet access point and the backup internet, I have to turn on the DHCP server function on this router in order to support wireless users but the problem is that if I turned it on; there might be some conflict for the LAN users. So what can I do?
My current ip structure is that
ip : 192.168.1.1 - 192.168.1.100
subnet mask : 255.255.255.0
Gateway : 192.168.1.254 (primary internet connection)
The ip on Ericsson W30 router will be 192.168.1.253 for backup internet and normal wireless.
In this case; if someone uses Wireless; he / she always access to internet through Ericsson router which is 192.168.1.253.
The gateway 192.168.1.254 and gateway 192.168.1.253 will be attached to LAN 24x7.
Because both gateway is on 24x7, if I turned on the DHCP server on gateway 192.168.1.253, I afraid that the normal LAN user will be the ip from this DHCP server and going to internet from 192.168.1.253 gateway too. I just want to the LAN user uses 192.168.1.253 gateway if the primary internet connection failed ONLY.