Configuring 2 routers on same home LAN

Question

I have a home network based on the following:

Netgear ADSL Router at 192.168.2.1 This is defaul gateway and manages DHCP from 192.168.2.2 to 192.168.2.100 the Router is connected to a switch. An ethernet cable runs from this switch to another switch in another room where I have appliances who get DHCP addresses from the Netgear.

I want to add wifi connection into this other room. I have an unused TP-LINK router, of the type with no-DSL port, just 4 ethernet LAN ports, 1 wireless interface and 1 ethernet port named WAN.

The TP-LINK setup is apparently easy. I connected the WAN port to the switch. I configured the WAN interface such as:

IP address: 192.168.2.101 (part of my main network) Subnet mask: 255.255.255.0 DNS: 192.168.2.1 (the router actually connected to the network)

The LAN setup must be different so I decided for:

IP address: 192.168.3.101 DHCP on (from 192.168.3.10 to 192.168.3.20) Subnet mask: 255.255.255.0 DNS: 192.168.2.1 (the router actually conncted to the network)

It works, that is I can access the internet from wifi devices connected through the TP-LINK. But I cannot access the configuration setup from any device in network 192.168.2.X and I cannot figure why.

I tried port routing from 192.168.2.101 to 192.168.3.1 but without success.

In the meantime I changed the way, linking the switch to one of the LAN ports of the TP-LINK and disabling DHCP. In this case the TP-LINK acts as a wireless bridge and everything works. But still I do not understand what is it wrong with the routed setup where I cannot access the device.

Can anybody help me understanding what is wrong?

Answer 1

Most routers limit the ability to access the configuration pages from the WAN port (normally the Internet), due to security reasons. They often have a configuration setting allowing this, which you can select if you have a reason for it.

You don't say which TP-LINK router you are working, but to get an idea of what I am talking about, look at this document http://www.tp-link.us/resources/document/TL-WDR3500_V1_User_Guide_19100.pdf, section 4.13.4 "Remote Management" on page 80 (and the screenshot on the following page).

Unless you change the default (and provide an IP address in the router above), you will not be able to access the router's configuration page from the WAN port.

Answer 2

While your setup does work, I think you would be much better off to ignore the WAN port on your TP-LINK, and connect a LAN port to the switch instead. That way you only have one network to manage. You can still use the wi-fi, and you'll be able to configure it from anywhere.

Answer 3

192.168.2.x is actually WAN for your TP-Link router (after a NAT in your router), and the routers generally have the settings to disallow accessing the interface from WAN network for security reasons.

You can do the reverse, that is access any of your devices at 192.168.2.x from your TP-Link connected devices which have the IP 192.168.3.x

192.168.2.x(WAN) ---> NAT(TP-Link) ---> 192.168.3.x(LAN)

Packets flow direction

192.168.2.x ---->| 192.168.3.x (Blocked)
192.168.2.x <----- 192.168.3.x (Pass)

The normal solution if you JUST want to access the interface, check for your router admin interface from inside its LAN and enable Remote Management if that option is available. You will be able to access the interface at 192.168.2.101 from any device on 192.168.2.x

If you want more control and want all the devices in LAN to talk to each other, you should consider using Access Point mode in your TP-Link router, which will disable NAT and will use the DHCP from your main router at 192.168.2.1 for all the devices connected, and everything will be on network 192.168.2.x which is better for a home network.

Thank you