Different modem and router IP addresses

I'll try to explain best I can.

My ISP gave me modem, that modem only has 1 WAN output (to connect to my router). I have TP Link router with WAN input and 4 LAN outputs. Basic connection is : straight LAN cable, from modem WAN output to router WAN input.

Router LAN settings are :

IP : 192.168.1.1

Subnet Mask : 255.255.255.0

DHCP Server is disabled on modem, but enabled on TP Link router, I have already setup DHCP to give my home PCs certain IP addresses.

Thing is, my modem has IP : 192.168.100.1

If I am not wrong they should not be able to communicate each other, because there is a different subnet mask on 192.168.100.1

How am I able to see my modem via router?

And off course how setup my network properly?

Thank you in advance.

EDIT : I do have occasional packet loss, is it possible to have that due to bad network configuration?

2 Answers

Better to enable DHCP in the modem and disable it in your TP Link router.

First set up TP-Link with:

• Static LAN IP in the same network as the modem, (192.168.1.254 mask 255.255.255.0) for example.
• Disable DHCP
• Enable WiFi if you have it.

To do this connect directly to it in isolation using , then you should be able to connect to it with

Then connect the modem to the TP-Link in any of the LAN outputs and you are done.

Anything you then connect to the TP-Link, via WiFi or LAN will get its IP from the modem because it is and should be the only DHCP server in the network, and everything will be able to connect to the Internet without extra NAT.

You should be able to manage the modem using and the TP-Link with . One network, easy.

I know everyone is over this question by now, but I couldn't help myself. First, your explanation was perfect. We all know what "see" means in networking, there's no need for further explanation. Second, your setup is most likely correct, the router is a much better option to be your DHCP server and anything else your network requires. Your modem should be used for that purpose only if possible, a modem. Third, the only way for devices to talk between subnets is to have a router involved. The router does exactly that, it routes traffic between different subnets. This is why you can see your modem from your router. I'm going to stop there since this post is so outdated. Thank you for posting. I'm sorry you were met with such aggression initially.