6 Replies Latest reply: Feb 24, 2012 8:58 AM by kazten2010
kazten2010 Level 1 (10 points)

I recently installed an AEBS to replace our completely hopeless BT Home Hubs 2.0 and 3.0. The AEBS connects to the internet via a Zoom X5 non-wireless modem and the network is extended with an Airport Express to reach the far bedrooms. This setup has worked beautifully with none of the slowing down drastically, going to sleep and disconnecting the the "energy efficient" Home Hubs did umpteen times a day. Anyway, at the initial setup, I looked into creating a guest network, but I was warned about conflicting NAT and I didn't have the time to delve further into it at that moment.

I thought after installing a software update to Airport Utility the other day that I would have another go, but when I entered the "edit" facility for the AEBS, I can set up timed access for computers to the network, but all mention of a guest network seems to have vanished.

Have Apple removed this facility? If so, is it coming back?

I reset the AEBS from bridge mode to DCHP and NAT to see if any other options appeared, but nothing.

All refernce to the guset network facility referes to the old Airport Utility before the update.

Has anyone got any ideas?

iMac, Mac OS X (10.6.8)
  • Bob Timmons Level 10 (98,254 points)

    Your Zoom "modem" is a gateway device, which combines a modem and router in one package. As such, your Z5 gateway is providing DHCP and NAT services on your network.


    With this type of device, AirPort Utility chose the correct Bridge Mode setting for your AEBS...since you only want one device on a network providing DHCP and NAT services.


    In order to enable the Guest Network, the AEBS must be confiigured as the "main" router on the network providing DHCP and NAT services. Since it cannot do this when the Zoom device is already providing these services, the Guest Network feature is not available.


    Sometimes, it is possible to configure the AEBS to act as a router anyway when there is another router on the network, but this can create IP address conflicts with two devices both trying to provide DHCP services for devices on the network. In addition, this type of setup will also create a Double NAT error.


    This might work with some routers and not others. If you were able to use the Guest Network with the Home Hub devices, they allowed this. The Zoom device likely will not.


    If the Guest Network function is important to you, you might want to look at a simple modem....not a gateway device.

  • kazten2010 Level 1 (10 points)

    Thank you Bob, I had a feeling that this might be the case. I have seen this sort of thing mentioned on other similar threads.


    Can anyone give me some examples of makes and models which qualify as a "simple modem" that will allow an AEBS to have a guest network? No one seems to have mentioned any particular examples anywhere of what constitutes these devices.


    Also Bob, I can access my X5 via my browser and it has various setup options. At the moment, its protocol is PPPoE, which was the default setting, but it can be changed to PPPoA, 1483 bridged (pure bridged mode), 1483 bridged IP and NAT or 1483 routed IP. Would changing to any of these allow me to configure the AEBS as the "main" router?

    The X5 is purely a wired ADSL modem and 4 port router - no wireless facility - and the AEBS is the only device connected to it by ethernet cable and is the only one that will be. All computers and mobile devices connect via the AEBS wireless network.

    Any advice appreciated.

  • kazten2010 Level 1 (10 points)

    Soory, I meant to say that my X5 also gives me the option to enable or disable NAT. What are the implications of disabling NAT at this point?

  • Bob Timmons Level 10 (98,254 points)

    I suppose that you could try to disable NAT on the X5, but that does not make it a simple modem....and you would still have two DHCP servers on the network....which may be being picked up by the AEBS as a conflict, so it won't likely allow the Guest Network feature to be enabled.


    You might want to check with X5 support to see if it is possible to configure the X5 gateway as a simple "bridge mode" modem. That would allow the AEBS to provide DHCP and NAT for the network correctly, which would enable the Guest Network option.

  • kazten2010 Level 1 (10 points)

    Thank you, Bob.


    I think I will wait until the internet is not in use and then bite the bullet and try switching the X5 to the 1483 bridged (pure bridged mode) and see what happens. I am wary of altering things when I don't quite understand them, but I can always switch it back!


    Thanks again.

  • kazten2010 Level 1 (10 points)

    I got a very quick response to a query to Zoom's online support and as long as I switch to the 1483 bridged (pure bridged mode) and enter the VPI value to 0 and VCI value to 38, then the X5 becomes a simple modem and the AEBS can be set to function as my "main" router without a NAT conflict. I can then set up my guest network.


    I hope this helps anyone who is having the same problem setting up a guest network on AEBS and needs something that will function as a basic modem. The Zoom X5 was reasonably priced and is very easy to set up and use and is more reliable than the BT Home Hubs we tried before and works beautifully with the AEBS, both as a router and as a simple modem.


    I was impressed with the speed of the online support from Zoom and the fact that the person helping me spoke to me in language I could understand and didn't blind me with science. I was taken through each step in turn.


    Thank you again, Bob, for pointing me in the right direction.