Questions

Help with network setup, connect modem<-- switch<-- router (DHCP?)

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Help with network setup, connect modem<-- switch<-- router (DHCP?)

noname12321
Hi,
I have a problem with my internet setup. I have a switch connected to my modem and when I connect a computer to it everything works. The problem is when I connect a wireless router to the switch it doesn't work. It doesn't seem to get the internet connection from the switch. Also when I connect a computer directly to the switch and I use the ipconfig command in cmd, there doesn't seem to be a gateway address. Anyways I am probably going to get a new switch but I still want to connect it to the modem. And I still need to connect multiple wireless routers to it. And I still need to connect multiple wireless routers to it. Do I have to setup a DHCP server? or are there switches with DHCP. Thanks for your help in advance.
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    4 Votes
    cmiller5400

    It would help if we had some make and model info for your modem, switch and router.

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    0 Votes
    norman

    You're going about this all wrong.
    1. The router, wired or wireless, connects to the (cable or dsl) modem.
    2. The router is what does DHCP to give IP addresses to multiple devices, and includes a built-in switch.
    3. Why do you need multiple wireless routers? If in fact you need to cover a large area with your wireless network, then what you want to do is plug multiple wireless ACCESS POINTS to the extra router ports or the switch.
    You DO NOT use multiple ROUTERS., unless you turn off DHCP on all except one. Having multiple DHCP servers running on a network is a recipe for disaster.

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    1 Votes
    Rob Kuhn

    Is your cable modem also a router? In other words if it's just a plain cable modem then it doesn't have the ability to provide DHCP so the switch really doesn't matter unless it's a L2/L3 switch in which case it would have DHCP/DNS services.

    With that said I'm going to go under the assumption that it's just a plain cable modem and what I would do is take the wireless router, plug the WAN side of it into the back of your cable modem. Then plug the LAN side into your switch.

    If my assumption is incorrect and your cable modem is also a router (it will have more than one LAN port on the back), then connet the WAN side of the Wireless router into one of the LAN ports on the router.

    Its your call if you wish to disable the DHCP service on the Wireless router or have it dish out DHCP to just your wireless devices. If you elect to do that then be sure to select a different IP network address range than what the cable modem is dishing out. If you want your wireless devices to connect/talk to devices that are on the hard wired side you will need to setup some routing accross the two networks.

    If you want to make this easier, and you happen to have two routers (the cable modem and your Wireless), I'd plug the WAN side into the LAN side of the cable modem and run everything off the back of the wireless router. This way you don't have any routing issues and you only have to deal with one DHCP server.

    What is the make and model of your cable modem, wireless router and switch?

  • +
    4 Votes
    cmiller5400

    It would help if we had some make and model info for your modem, switch and router.

    +
    0 Votes
    norman

    You're going about this all wrong.
    1. The router, wired or wireless, connects to the (cable or dsl) modem.
    2. The router is what does DHCP to give IP addresses to multiple devices, and includes a built-in switch.
    3. Why do you need multiple wireless routers? If in fact you need to cover a large area with your wireless network, then what you want to do is plug multiple wireless ACCESS POINTS to the extra router ports or the switch.
    You DO NOT use multiple ROUTERS., unless you turn off DHCP on all except one. Having multiple DHCP servers running on a network is a recipe for disaster.

    +
    1 Votes
    Rob Kuhn

    Is your cable modem also a router? In other words if it's just a plain cable modem then it doesn't have the ability to provide DHCP so the switch really doesn't matter unless it's a L2/L3 switch in which case it would have DHCP/DNS services.

    With that said I'm going to go under the assumption that it's just a plain cable modem and what I would do is take the wireless router, plug the WAN side of it into the back of your cable modem. Then plug the LAN side into your switch.

    If my assumption is incorrect and your cable modem is also a router (it will have more than one LAN port on the back), then connet the WAN side of the Wireless router into one of the LAN ports on the router.

    Its your call if you wish to disable the DHCP service on the Wireless router or have it dish out DHCP to just your wireless devices. If you elect to do that then be sure to select a different IP network address range than what the cable modem is dishing out. If you want your wireless devices to connect/talk to devices that are on the hard wired side you will need to setup some routing accross the two networks.

    If you want to make this easier, and you happen to have two routers (the cable modem and your Wireless), I'd plug the WAN side into the LAN side of the cable modem and run everything off the back of the wireless router. This way you don't have any routing issues and you only have to deal with one DHCP server.

    What is the make and model of your cable modem, wireless router and switch?