Connecting A Router to Another Router (Now with Follow-Up Questions)

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I would like to set up a home network with two routers in order to expand my coverage and also have an additional number of ethernet ports. For simplicity, I will refer to two routers as Router A and Router B.

I would like to connect Router A to the cable modem, and then connect Router B to Router A using an ethernet cable. Router A is a Linksys E2000. Router B is a D-Link DIR-615 C1. Both Routers run DD-WRT.

I'm wondering how to go about this? Will it be tricky? My naive thought would be to simply hook a cable up between one of the ethernet ports on Router A, and the Internet port on Router B.

Update: Followed the answers and disabled DHCP on Router B. I can now connect to the internet through a wired connection that runs through Router B. If anyone has time, I have some quick follow-up questions:

1) Does Router A assign an IP address to Router B? Is there a benefit of making this static?

2) Is there a way to use Router B as a Range Extender for my Wireless Network?

3) When I connect to Router B through a wired connection, how can I access it's settings page (when I type in 192.168.1.1 it automatically goes to the settings page of Router A)

Berk U.

Posted 2011-06-10T06:38:06.063

Reputation: 291

Answers

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If you connect two routers, don't connect either of them using the Internet port, because those are meant for WAN/modem connections only. Just connect them through the regular LAN ports.

I just quickly made this diagram, your setup should look something like this.

network diagram

Note that by default each router will try to assign its own IP address (mostly static) and assign IP addresses to its clients using DHCP (dynamic). In order to get around conflicts here, configure only Router A to use DHCP. Disable DHCP on Router B.

That way, Router B will almost act as a simple switch and access point. It doesn't really need to know about the fact that it has internet access, as it just forwards everything to Router A.

In order to prevent interferences, make the routers transmit their signal on a different channel.


To answer your questions from above:

Does Router A assign an IP address to Router B? Is there a benefit of making this static?

Yes, it will probably do that unless told otherwise. Making both Router's IP addresses static surely helps you in case there are DHCP errors or your DHCP static leases are not working. It's just keeping things static that should be static.

When I connect to Router B through a wired connection, how can I access it's settings page (when I type in 192.168.1.1 it automatically goes to the settings page of Router A)

That's probably because 192.168.1.1 is Router A? You might want the following settings:

  • Router A: Manually set its IP to 192.168.0.1, enable DHCP, beginning at 192.168.0.3
  • Router B: Manually set its IP to 192.168.0.2, disable DHCP
  • Both subnet masks should be 255.255.255.0 – just saying because you were talking about 0.1 and 1.1 addresses which would indicate you're trying to have a bigger subnet. It'd just make things more complicated

That way you'll make sure they don't interfere and you can access them always through the same IP.

Is there a way to use Router B as a Range Extender for my Wireless Network?

Please open a separate question for this issue, as this one's already answered and probably nobody will care to write another answer. In general, you should always try to make separate questions for different issues on Super User and don't add follow-up questions to ones that are already answered.

slhck

Posted 2011-06-10T06:38:06.063

Reputation: 182 472

Quick question: does Router A assign Router B an IP address in this case? Also, is there a way to use Router B as a Range Extender for the Wireless Signal in Router A? I have both Router A and Router B running DD-WRT now. – Berk U. – 2011-06-13T16:26:18.000

Depends on the configuration. Router B should be able to get an address assigned automatically if 1) you tell it to and 2) Router A has DHCP activated. A safer way would be to statically assign, for example 0.1 to Router A and 0.2 to Router B, and then let the DHCP range begin at 0.3. Range extending depends on the hardware capabilities but I guess DD-WRT can do it. Your best bet would be to look in the documentation and/or open another question in case you can't work it out. – slhck – 2011-06-13T16:29:33.783

Thank you for this.

For 1): How can I tell Router B to get assigned an IP address?

For 2): Just to be sure, since DHCP is only enabled on Router A, I'm going to access the setup page of Router A and assign 192.168.0.2 as a static lease for Router B. Right? – Berk U. – 2011-06-13T16:41:58.667

I don't know DD-WRT, but there could be some setting. I'm not too sure though. It wouldn't always make sense for a router to get a dynamic internal address. But as I said, it's better if you do so: 1) Activate DHCP on Router A, but let the DHCP range begin at 192.168.0.3 2) Set Router B's IP address to be 192.168.0.2. No need for static leases. That way you can still get to Router A and B in case something doesn't work with the DHCP leases. – slhck – 2011-06-13T16:46:23.120

I updated my answer to reflect all that. – slhck – 2011-06-13T17:13:17.757

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I would not get a second router, but an actual cheap switch. I have have many cases where the switch on one of these routers does not act properly when connected to another switch since there is an aspect of routing introduced. If you do buy a router, and connect it as slhck said, and it does not work, this will be why.

KCotreau

Posted 2011-06-10T06:38:06.063

Reputation: 24 985

There is a chance it might not work, so +1 for that, but then again you don't have extended WiFi and would need to get an AP. – slhck – 2011-06-10T18:16:26.550

I'm seriously considering this. What type of switch would you recommend?

When I connect to the network using an Ethernet port on Router B, my connection occasionally slows down significantly for 1-2 minutes. I played around with this for a while, and I believe that there are occasional routing conflicts between Router A and Router B (during the slowdown, 192.168.1.1 directs me to setup page for Router B; when the internet works properly, however, 192.168.1.1 directs me to the setup page of Router A). – Berk U. – 2011-06-13T16:37:11.327

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Yes, that is all you have to do. Router B should be configured in a way that

  • Bridging
  • No DHCP server
  • Direct internet connection
  • WLAN on different channel (with a gap of 6 channels between A and B)

Thor

Posted 2011-06-10T06:38:06.063

Reputation: 276

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I have a pair of DLINK 4500's attached like this

ISP<--->WAN RTR A LAN<--->WAN RTR B LAN/WIFI<--->PC's

Router A
    Wan Port - DHCP from ISP
    LAN Ports - DHCP Enabled - Range 192.168.2.3 - 192.168.2.254  /24
    Router A IP address - 192.168.2.1 /24

Router B 
    Wan Port
        Ethernet cable to Router A LAN Port
        192.168.2.2 /24
    Lan Port (includes wireless) -  DHCP Enabled - Range 192.168.1.2 - 192.168.1.254  /24
    Router B IP address - 192.168.1.1/24

Works like a charm.

dbasnett

Posted 2011-06-10T06:38:06.063

Reputation: 459