Airport Express and secondary DHCP allocations

Discussion in 'Mac Accessories' started by MentalFabric, Jan 3, 2013.

  1. macrumors 6502

    MentalFabric

    Joined:
    Mar 10, 2004
    #1
    Hi all,

    I've got airport express providing my wifi attached to a Thompson router - unfortunately the Thompson is fairly unreliable and needs to be restarted on a regular basis which takes down the whole network presumably as it provides the DHCP - this means airplay is interrupted when the router goes down.

    So I'm wondering whether I can use the 'DHCP only' option on the AE in router mode to have it allocate IPs on either the same or a different range in order to keep at least the local network up when the router goes down. Does anyone know whether this would work or any other solution that would?
     
  2. macrumors 65816

    drsox

    Joined:
    Apr 29, 2011
    Location:
    Xhystos
    #2
    Can you turn off the local DHCP/NAT functions on the Thompson router (i.e. get it to act as only a modem) ? Then you can use the AE as the sole router with DHCP and NAT active, connecting to the Thompson as the modem.
     
  3. macrumors P6

    Weaselboy

    Joined:
    Jan 23, 2005
    #3
    You can setup the two devices on different subnets and that will allow you to leave DHCP on with both. So one would be on say 192.xxx.xxx.x and the other on 10.xxx.xxx.x.
     
  4. thread starter macrumors 6502

    MentalFabric

    Joined:
    Mar 10, 2004
    #4
    Thanks for the help guys, I can set up the router in bridged mode to use the AE for DHCP but I'm using a few ethernet ports on the router and I'd rather not have to find an ethernet switch to plug in to the AE so I think the preferred option would be to set up another subnet for the wifi on the AE - how would I go about that? When I try to switch to DHCP only mode it says I need to manually configure a WAN IP address...
     
  5. macrumors P6

    Weaselboy

    Joined:
    Jan 23, 2005
    #5
    What you want is the Airport and Thompson on different ranges of addresses. Look at this screen in Airport Utility and you should see the AE is on the 10.xxx range. Check the Thompson to see what range it runs on. If it it already 192.xxx you are good to go. If the Thompson is 10.xxx, then change the AE to 192.xxx.

    [​IMG]
     
  6. macrumors 65816

    drsox

    Joined:
    Apr 29, 2011
    Location:
    Xhystos
    #6
    Do you want the wired devices to see the wireless devices and vice versa ? If you do then IMO a switch is going to be necessary.
     
  7. macrumors P6

    Weaselboy

    Joined:
    Jan 23, 2005
    #7
    Good point.
     
  8. macrumors newbie

    Joined:
    Dec 12, 2011
    #8
    Bridge Mode

    Did you get this resolved?
    Forgive me if this is already resolved, but I figured I'd share this in case you're still dealing with intermittent (or repetitive) network problems.

    Your Thompson modem/router might be working fine. Sometimes, one of the problems when you have routers linked while on the same subnet is that you have the two sort of fighting to assign IP addresses. You get kicked off the network because you have too many chefs in the kitchen.

    Here's what I do... but it's not the only option. However, it works great for having multiple routers on the same subnet and not have to switch networks to access different devices. I personally prefer this setup when I'm not using different subnets.

    1. Setup your Thompson Modem/Router same as normal as if you don't have another router.
    2. Set your Airport Extreme in Bridge Mode
      • Network Tab > Router Mode > Off (Bridge Mode)
      • Wireless Tab > Network Mode > Create Wireless Network (you fill in the rest of the info)
      • Internet Tab > Connect Using > DHCP
    3. Connect AE to Thompson Router with ethernet cable from LocalPort to LocalPort. DO NOT use "Internet Port" on AE. It won't hurt the devices, but it simply won't work because AE will be looking for different info.

    With this setup, the Thompson router is the only one that assigns your IP addresses. The Airport Extreme functions simply as a Wi-fi, transmitting the IP addresses assigned by the Thompson router. Now, no matter which Wi-fi you use, you can access all your devices without switching networks – printers, Apple TV, Blu Ray device, AirPlay, etc.
     
  9. drsox, Feb 13, 2013
    Last edited: Feb 13, 2013

    macrumors 65816

    drsox

    Joined:
    Apr 29, 2011
    Location:
    Xhystos

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