wireless networking - What happens when I plug a router into another router?

08
2014-07
  • zack_falcon

    I've recently switched ISPs, and the new one provided me with a modem (that what you call those things?) that doubles as a router.

    I used a router on my previous ISP for wireless networking, but I've since taken it out of the equation to simplify things.

    Basically, my setup went from:

    WiMax Cable -> Modem -> MyRouter -> PC/Laptop

    To:

    Broadband Cable -> Modem/Router -> PC/Laptop

    But, there are some problems.

    For one thing, my ISP forbids me from changing my router password. I'm not concerned about security, as the password is long and complex enough, but that's the problem - every time a guest comes over and asks for access I have to recite this long string from a box. I'd much rather have my own password that I change regularly.

    Second, during times of questionable connectivity, I often restart the modem. And I'm pretty sure that would also take down the wireless network, right?

    Finally, the modem/router's range is pretty poor. My own router can at least spread the connection beyond the house. This one can barely push it out of the room it's in.

    So, I want to change my setup from above, into this:

    Broadband Cable -> Modem/Router -> MyRouter -> PC/Laptop

    I'll be treating the Modem/Router as a Modem and plug in to my router via LAN cable.

    What I want to know is:

    • Will it affect my internet connectivity / introduce latency etc., etc.
    • Will it affect my network / jumble up IP addresses and make local connections more of a pain than it already is.

    Thanks.

    • Answers
  • Paul

    If you are unable to make changes to the ISP router, then I would use your own wifi router, but use it as a layer 2 device, rather than as a router.

    All this means is that the devices that connect to your router are on the same network as if they were connected directly to the ISP router.

    The way to do this is to disable DHCP on your router, and connect it to the ISP router using LAN ports. This is important. Your router probably has a WAN port - ignore this and connect one of the lan ports to the router LAN port.

    Now anything that connects to your router will issue a DHCP request for an IP address. Your router DHCP will be disabled, and as the LAN ports are connected, the ISP router will see the DHCP request and respond.

    This is far simpler than the alternative of trying route twice. I would recommend disabling the wifi on the ISP router if you can, otherwise it is just using up radio bandwidth.


    • Related Question

    wireless networking - Configuring WLAN with router connected to modem
  • GPX

    I currently own an ADSL modem. I am planning to buy a D-Link DIR 600 Wireless Router, for setting up a wireless network to play Counter Strike with my buddies. I have a few questions.

    1. How do I set up the router? Am I correct in thinking that I should connect my telephone wire to my modem, my modem to my router, and then my router to my PC?

    2. If I switch on WiFi on the router and let my friends connect to the network to play CS, will the game be actually be played locally or through the internet?

    3. How do I set up only LAN-sharing, without internet? Is it easy to switch between LAN-only sharing and traditional internet sharing?

    EDIT : My ADSL modem is also a router, but it has only 1 ethernet port, which is currently connected to my PC. So I will be connecting my wireless router to my ADSL modem/router.

    To add to question #3:

    After I finish playing CS, I want to be able to continue using the internet on my PC, after switching off WiFi; i.e., stopping my router from beaming my internet connection. How do I do that?


    • Related Answers
  • Majenko

    The existing ADSL router is all you need to connect to the internet. Adding a second router is both pointless and expensive. A cheap cable router of the type you are looking at will not work with your ADSL router.

    What you require is a small (maybe 4 of 5 port) switch to increase the number of ethernet ports available on the existing router, and a wireless access point to share the network out as and when you want it.

    Sample Network

    When you want to disable all access to the network through wireless means you can just unplug or turn off the wireless access point.

  • M'vy

    1. If your router is a ADSL-modem/router, you can get the ADSL modem out and just connect the router (you'll need to know the ADSL configuration of your ISP : protocols + credentials). But else your are right. The router will get the public IP from the modem and dispatch to the other networks (Affecting an IP to each if DHCP is active).

    2. If your friends connects to the wireless and your are playing a game, it will be on LAN if the server is on the LAN and you connect to it via a local address (192.168.x.x for example), but if the server is online, it would of course, be through internet. Undefined behaviour if you join a game from a list on the internet and it "fortunately" ends being a server hosted locally : would depend on the games I guess.

    3. You can just disconnect the router from the modem, or maybe the router has an option to close a port. Then all traffic can only go between peers. Be advise that LAN-Sharing for file etc may have to be enabled on the OSes. For games, it's generally not a problem since it's just networking stuff. Then if the hosts can pings that should be ok (!!Firewalls!!)