New router issues with connection from BT Hub

[Rob_B]

Why is networking so hard?
I am on Plusnet and have been using a Plusnet Hub and a pihole for DHCP/DNS, I've now bought a TP Link AX10 and am trying to use the Hub as a modem only and the AX10 as a router.

Now onto my issues but ignoring the Pi (for now) ...

I turned off the wireless network on the Hub.
I plugged CAT5 into the LAN port on the Hub and the WAN on the AX10
I turned on DHCP on the AX10
...and everything kinda seemed fine, until I made some small config change (I don't even recall)

The AX10 said 'no internet', the Hub DOES have internet and if I turn the wireless back on I can connect to it and browse with no issues, the AX10 even after a reboot and restore does NOT see the internet coming from the Hub.
I pressed the reset button on the back of the Hub and the internet came back (I then had to turn off the wireless again and everything stayed fine)

Now I tried to put the Pi on the network, I had to do a full reinstall of the OS/Pihole as it wouldn't connect and I changed the AX10 DNS to point to the Pi, again I'm now getting 'no internet' although again the Hub IS connected to the internet.

On the 2nd time with an issue the AX10 changed it's IP so now the setup is:

Hub : 192.168.1.254 - DHCP off. Internet connected fine
AX10: 192.168.2.1 - DHCP on. DNS set to ISP default. Default gateway 192.168.2.1. Internet connection type IP addresses/subnet mask/default gateway all come up as 0.0.0.0.

Any ideas? The internet connection on the AX10 is setup as 'dynamic IP' should this be static and point to the Hub (IP/gateway) and should the subnet mask be the same as the Hub 255.255.255.0 ?

I'm really lost here, I've reset everything I can find and I'm getting nowhere, help!!

Rob

[DDY]

By disabling DHCP on the PN Hub the AX10 isn't getting an IP (for its WAN interface) from the PN Hub, hence 0.0.0.0.

You can either enable DHCP on the PN Hub or give the AX10 a static IP for its WAN interface on the same subnet and range as the LAN of the PN Hub. e.g. 192.168.1.253 should work. Note that the 192.168.2.1 address you gave the AX10 is for its LAN interface.

Enabling DHCP on the PN Hub will only give an IP address to the clients connected to its LAN, such as the AX10, it won't give addresses to anything connected to the AX10 if that's connected to the PN Hub on its WAN interface.

As far as I know the PN Hub cannot bridge its WAN connection, that is, it doesn't have a "modem mode". Unfortunately that means you can't really use it as a modem-only in a sense that the routing fuction cannot be turned off.

EDIT: Another thing you can do is simply let the PN Hub do all the routing and use the AX10 as a switch and access point, and delegate DHCP and DNS to the Pihole.

[Rob_B]

OK, so if I enable DHCP on the PN hub does that have any downsides? Sounds like it won't?

I had read about no bridge mode, assuming I enable PN DHCP to give the AX10 an IP and then disable the PN wireless networks am I losing anything really? I'm not clear if any particular option is 'best' so I think I'm go with :

DHCP on PN hub ON
DHCP on AX10 ON
Pihole for DNS only

[DDY]

In terms of DHCP, no issues really. Tunrning off wireless if you don't need it on the PN Hub is a good move in this situation.

But without bridge mode you can run in to issues having two NATs, not a huge problem from experience. I lived in a shared house for many years and I had my own router that connected to the main house router so I could have my own network. Just meant I had to open ports and forward on both routers if it came to that, in your case you can just DMZ the AX10's WAN IP address.

[Rob_B]

Thanks a lot

Setup now, I can't seem to give the pi a static IP even though it shows as a client in the AX10 in one place but not when adding as static, I'll cross that bridge later!
As for Nat issues... I'll wait and see what happens, I've nothing too complicated going on so hopefully it'll be fine.

I hate networking.

Thanks again!

[Saracen999]

First, I am not a networking guru. So I may be misunderstanding either what you did, or what you're trying to achieve.

But a few monts back I did what is functionally the same thing, albeit with a VM hub and Asus router, from using the VM as modem and router.

It went :-

- turn VM device into "modem only" mode. That turned VM wifi, and all routing functions off.

- plug in, connect up and turn on Asus router.

It thought about it for a minute or two, asked me for Wifi details etc, set itself up and worked. DHCP, NAT etc is all handled by the Asus router and the VM device is just a dumb modem, with zero routing functionality.

Oh, and yeah, I had to tweak a few Asus settings to lock it down a bit, for my own peace of mind. That took some reading and twiddling. But all the IP assigments, etc, were just handled by the Asus. I could override them manually, but haven't needed to.

What I didn't see in your description is the "put ISP hub into modem mode" bitg. Unless you're not doing that for a reason?

[Rob_B]

The Plusnet (and BT hub that I have spare) don't have a modem only mode, me disabling DHCP on the Plusnet router was the reason for the error :/

[Saracen999]

Ah. If it doesn't have one, that would make it tricky to enable, I guess.

[Rob_B]

More issues!

I noticed that most clients weren't using the Pihole
So I tried to change the DNS setting. There are 2 places it's found :

Advanced>Internet >DNS
And
DHCP>DNS (says optional)

I had the second set to my pi, which worked but not all devices used it, then I tried to change the main DNS from "get from isp" (says 192.168.1.254) toy pi, and everything went offline again!

Any ideas?

[DDY]

Is the Pihole connected to the PN Hub or AX10?

[Rob_B]

Neither on a hard line, it's a Pi zero so is WiFi onto the AX10.

I've just disabled DHCP on the AX10 and enabled it on the pi, also changed the LAN IP back to .0.1 instead of .2.1 as I the AX10 changed it after I set the pi up so I couldn't connect to it.

Nothing more has broken... Yet...

[Kanoe]

This seems to be a common thing for Openreach based ISP's.

Had the same thing when switching over to Sky as read that there box didn't have a modem mode either.

They suggested a couple of Modem / Routers that did have modem only mode that would work with there network and even gave me the £30 to buy it.

The only downsides to this approach i can see is that:

1) Have to spend some more money but it does mean if i move to another openreach ISP I can reuse the gear anyway for £30 (TP Link TD-W9970)

2) Lost the ability to use the "landline" as Sky only provide VOIP that handsets have to be plugged into their box to get to work. My Router does support VOIP but not been able to find the config details I would need to get it to connect to Sky's service. But as the benefits of the landline are all but gone these days with the move to VOIP, like being able to use it even when power goes off, decided it was the time to ditch it anyway