[SOLVED] My ISP recently gave me a new modem and now everything is broken ?

[castedbounds]

My internet service provider is having an infrastructure overhaul, switching every home to fiber optic from coaxial.

Along with this overhaul, they gave me a new modem (because the old one was for coaxial. The new one is for fiber).

The problem that I'm having is that this new modem doubles as a router. I already have my own router and I wish to continue using it instead of the one provided by my ISP.

Something about this new ISP-provided router is preventing my personal router from connecting to the Internet. At first I thought it was a local IP conflict (which turned out to be one of the problems) and I swiftly fixed that by giving the ISP-provided router "192.168.3.1" and my personal router "192.168.1.1".

My personal router still isn't able to connect to the Internet after fixing the IP conflict.

I suspect this is something to do with the DHCP server because both routers have their DHCP servers enabled. Correct me if I'm wrong, but as far as I know the DHCP's job is to give IP addresses to local clients? Is this a thing that can be done with two routers?

One last thing, my personal router is connected to the ISP-provided router via one of the LAN ports.

Phew! That was a lot. I would appreciate any help or suggestions here 'cause networking is really not my forte!

Thanks in advance.

 

[kanewolf]

My internet service provider is having an infrastructure overhaul, switching every home to fiber optic from coaxial.

Along with this overhaul, they gave me a new modem (because the old one was for coaxial. The new one is for fiber).

The problem that I'm having is that this new modem doubles as a router. I already have my own router and I wish to continue using it instead of the one provided by my ISP.

Something about this new ISP-provided router is preventing my personal router from connecting to the Internet. At first I thought it was a local IP conflict (which turned out to be one of the problems) and I swiftly fixed that by giving the ISP-provided router "192.168.3.1" and my personal router "192.168.1.1".

My personal router still isn't able to connect to the Internet after fixing the IP conflict.

I suspect this is something to do with the DHCP server because both routers have their DHCP servers enabled. Correct me if I'm wrong, but as far as I know the DHCP's job is to give IP addresses to local clients? Is this a thing that can be done with two routers?

One last thing, my personal router is connected to the ISP-provided router via one of the LAN ports.

Phew! That was a lot. I would appreciate any help or suggestions here 'cause networking is really not my forte!

Thanks in advance.

You want the WAN network and that LAN network on your personal router to be different. If your LAN network is 192.168.1.x then the WAN network needs to be 192.168.20.x (something different in the THIRD digit).
Assuming you want your personal router to be a router, then the ISP has to be connected to the WAN port on your personal router.
You need to contact the ISP and ask them if their router can run in "bridge mode" Or google the ISP router model and "bridge mode" to find instructions on changing it to act like a modem rather than a router. THAT is the best answer.

 

[castedbounds]

You want the WAN network and that LAN network on your personal router to be different. If your LAN network is 192.168.1.x then the WAN network needs to be 192.168.20.x (something different in the THIRD digit).
Assuming you want your personal router to be a router, then the ISP has to be connected to the WAN port on your personal router.
You need to contact the ISP and ask them if their router can run in "bridge mode" Or google the ISP router model and "bridge mode" to find instructions on changing it to act like a modem rather than a router. THAT is the best answer.

Hi kanewolf, thanks for the extremely quick reply! It looks like bridge mode is exactly what I'm looking for. However, it seems to be disabled in my ISP's router as per their config. No matter though, hopefully that can be rectified.

For now, let's assume bridge mode is there. My internet service provider doubles as my cable TV provider. It seems that when they switched to fiber, their cable TV decoders now rely on the ISP router (connected through the LAN ports) to get its signal. If I turned on bridge mode, would this break the cable TVs?

 

[kanewolf]

Hi kanewolf, thanks for the extremely quick reply! It looks like bridge mode is exactly what I'm looking for. However, it seems to be disabled in my ISP's router as per their config. No matter though, hopefully that can be rectified.

For now, let's assume bridge mode is there. My internet service provider doubles as my cable TV provider. It seems that when they switched to fiber, their cable TV decoders now rely on the ISP router (connected through the LAN ports) to get its signal. If I turned on bridge mode, would this break the cable TVs?

I don't know. But it is very possible.
You will probably have to leave their router as a router to keep your TV.
What is it that you believe is better in the router you have now ?

 

[SamirD]

I dealt with a similar issue a couple of years when our provider changed gear. So we had to deal with the isp router, but we could put our equipment in the isp router's dmz, which basically let our router function like normal.

To do this, the first thing you have to do is get your IP subnets correct (as instructed in the posts above) and then make sure your router's wan port connects to the isp lan. Then you will want to have a dhcp reservation in your isp router for your router so the IP will always be the same, and then set that ip to be in the dmz in the isp router. This should give your router full access like it normally did.

 

[castedbounds]

Unfortunately it looks like my ISP is very restrictive and won't allow bridge mode or even DMZ. I'm forever stuck with their router.

I wanted to use my own router because it had a logical web UI, flexible controls and (the biggest one) stable speed.

This new ISP-provided router fluctuates download speed like hell, even on an ethernet connection. I could be downloading a file at 7 MB/s then the next second drop to 1 MB/s.

Oh well, c'est la vie! Thanks for all the help guys, appreciate it <3