What IP address ranges are valid on the Smart Hub 2

[oldskoolsandhu]

Hi All.

what IP address ranges are supported.

i know 10.1.** is used for the public BT wifi network.

I do not want to use the 192.168* range as i have a view virtual machines and a cloud setup that uses the same range.  At the moment im routing everything via a Draytek but want to get rid of that.

Main issue my wifi around the property is poor and upgraded to the Halo system

[ptrduffy]

Per this wiki page you should be able to use 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16.  You can obviously subnet these further, and use 10.10.10.0/24, for example.

Do you need all of 192.168.x.y for your VMs and cloud?  You can easily set the hub to, e.g., 192.168.200.0/24 rather than the default.

I'm not sure I understand your comment about "getting rid of the Draytek" - if that means you want your SH2 to manage routing for your cloud/VMs then they will need to be in the same subnet as your SH2.

[Crimliar]

The basics of the LAN ranges and their subnets are laid out in RFC1918, but there are other conventions too!

There is nothing to stop you using 10.1.x.x as its "none-routable".

Conventions are that:

10.x.x.x has an 8 bit gobal prefix and a single 24 local addressable space.

172.16.0.0 - 172.31.255.255 conventionally uses a 12 bit global prefix, a 4 bit local prefix, and 16 bits of locally addressable space

192.168.x.x conventionally uses a 16 bit global prefix, a 8 bit local prefix and 8 bits of locally addressable space.

Actually once you've a LAN set within the range of a global prefix, there's little to stop you defining the subnets as you please, as these tend to be convention and not rules!  One thing that can cause issues though, is how many LAN addresses your router is set up to use, which on most of our consumer routers is just (often none contiguous) 256, with a number of those being reserved.

For simplicities sake I'd probably pick a single 16 bit address space somewhere between 172.16.0.0 and 172.32.255.255 with the DHCP allocating within a single 8 bit range.  And you will be at the mercy of the router DHCP working as expected - it may not!

[countrypaul]

Bear in mid that BT use 172.16.13.x and 172.16.12.x and probably some more in that range often (but not always) as the first BT router your own router connects to. Try "tracert -4 www.google.com" for example to see.

Edited to clarify that this is not always the case - as pointed out by @ptrduffy 

[ptrduffy]

I think this came up recently on another thread, but that doesn't seem to be consistently the case - there's no 172.x.y.z in any of my traceroutes (unless they're hops 2 or 3 which aren't responding?)

[Crimliar]

Hate to say it, but here's my trace route to www.google.com

And it's clearly routing through 172.16.18.229!  So 172.16.x.x is potentially a problem.