How to connect 192.168.1.x network to 192.168.100.x gateway?

Question

Hello fellow networkers. I am very new to this world and don't know a great deal about IP addresses and subnetting. I however stumbled upon quite a big problem (for me at least - haha) My entire network and infrastructure I have built is all in the 192.168.1.x / 255.255.255.0 range. Up until now I have had a router/modem that I have always used in modem mode with an IP I could change; said IP would be 192.168.1.254 and would be the gateway which the DHCP (windows server) would use. Everything worked fine until I had to change the router/modem. This one comes with a fixed IP in router mode: 192.168.100.1 Which makes it unusable for me. Is there a way to still use it or re-map it somehow in DHCP (windows server)? I am thinking maybe translating the address, but I don't know how to do it. Ideally I wouldn't change the current configuration, it's a lot of machines and mappings, etc... it would take me a long time! Thanks a lot for any help!

Answer 1

Hi Rafael, if the new router's inside interface IP address is truly unchangeable (super rare), you could look at adding another router to the inside of your new router. The outside interface of the add-on router could be set to 192.168.100.2/24 (assuming a /24 network). Then the inside interface of the add-on router could be configured back to 192.168.1.254/24. Remember to set your default route for traffic (0.0.0.0 0.0.0.0) to go out the outside interface toward the internet. Let me know if you'd like help. Happy networking!