Multiple subnets with AX7501-B0?

killerfoxi Posts: 2
edited October 2021 in Smart Home Product

I try to setup multiple subnet segments beside my trusted LAN on an AX7501-B0. Unfortunately there's almost no documentation out there how to do that. The "Additional subnet" in the "Home Networking" section doesn't cut it. I need to have multiple subnets. Is that even possible with this router? If not, why is there a possibility to add VLANs? Also the little text box which is a description or documentation about it, says that Zyxel supports multiple IP aliases (e.g. multiple subnets on the same interface group). I just haven't figured out how to do this. Help?

All Replies

  • tonygibbs16
    tonygibbs16 Posts: 362  Master Member
    Hello @killerfoxi

    Subnetting is an interesting topic, and one that can be discussed & learnt. Kevin Wallace does a basic subnetting tutorial as part of his Cisco training courses at

    Subnets happen at Layer 3 (Network layer) of the 7-layer OSI-Reference Model (OSI-RM) whereas VLANs happen at Layer 2 (datalink layer) of the OSI-RM.

    Looking at section 8.5 of the user guide, available under Downloads & resources from , it seems like the IP alias function allows you to put in an IP address and it will then give you a subnet mask dependent on the IP address you put in.
          - but the manual does not give a clue as to what the device is working out in order to give subnets.
                 - usually the subnet mask is used to subdivide the IP address space so that you know how many hosts (i.e. devices) can be in each subnet by design.

    My suggestion is that if you need to do subnetting is to connect a router or a layer 3 switch to the LAN interface of your AX7501-B0 and do the subnetting on that connected router or layer 3 switch.

    Kind regards,
  • I know that VLANs are on Layer 2, however, I need to route between those (with different IP addresses; Layer 3). I find it kind of weird to need another router, just do to that if it supports already half of it. Also I don't want to add another router, because of double NATing and it kind of defeats the point of having a internet router in the first place, no? I might as well just put it into bridge mode and use it as a dump media converter... but then I probably better of with a different brand for the routing all together.

    I'm not asking for much, just for support of multiple subnets.
  • tonygibbs16
    tonygibbs16 Posts: 362  Master Member
    edited October 2021
    Hello @killerfoxi

    It might sound extra, but it could be that the AX7501-B0 does not do what you want.

    As an example, Kevin Wallace did a tour of his home networking setup earlier this year, see , and he put a router connected to his AT&T router for his fibre broadband precisely to give himself a place to do subnetting in his home network.
           - he used a product called Firewalla Gold, which is a 4-port router and more.

    The AX7501-B0 may not do what you want, and I with my CCNA Routing and Switching certification could not work out from the manual how it could do what I think that you would like to do.

    Hence my suggestion.

    If you added another router, then you would not have to have double-NATing. You could have just routing and subnetting.
          - you could then use the router to go between subnets, and then have a default route to the Internet via your AX7501-B0.

    You would not have to make the AX7501-B0 into a dumb bridge I think.

    I don't work for Zyxel so this is my personal opinion.

    Kind regards,

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