Hub One Router as AP

[#1]

Hi all, I'm currently using our Plusnet Hub One (PHO) router as an AP behind our enterprise class router (ECR) using PPPoE on the (ECR), thing is I can't get it to connect with PPPoE on the (ECR) if it is directly connected to the (ECR) on one of its ports, it only connects if the PHO is connected to a managed switch port (unconfigured) then into a port on the (ECR).. Has anybody any idea what may be causing the PPPoE connection to fail in this manner?

Many thanks..

[#2]

Hi @housty welcome to the forum

Love your use of TLA (three letter acronym)

You need a modem with a router, which one (modem) are you using? The PHO does not have a bridge mode option, turning off DHCP and Wireless on the PHO does not make it a modem

[#3]

Hi @Dan_the_Van; not sure I follow you, I have the PHO working as an actual AP not as a router, I simply issue the same response as plusnet would from their PPPoE server and assign a IP to the WAN port.. It works but only if I put a managed switch in front of the AP, not if I connect the AP to the ECR..

PLUSNET-->ECR-->MANAGED SWITCH-->(PHO AS AP)  

the above works..

PLUSNET-->ECR-->(PHO AS AP)

the above never connects to my PPPoE server on the ECR?, something strange is happening.. I can connect any device that to the ECR and assign a PPPoE connecton to it but for some strange reason the PHO needs a managed switch between both..

housty

[#4]

@housty 

If you are on FTTC you need a modem between the dsl input from your filter and a router. There is one built in to Plusnet hubs.  These are combined modem/routers. The Hub One cannot be used as a simple bridge modem. 

[#5]

sorry guys, let me explain a bit better, I'm not bridging anything here.. I'm simply reutilising the PHO as an AP on my network by assigning the WAN port and IP from my own router using PPPoE server.. this all works as it should, the problem is I have to insert a managed switch between the PHO AP and my own router or the PHO AP drops the PPPoE frames thus not connection on its WAN port..

So all I'm wanting to know is what is wrong with the PHO that it requires an actual managed switch between the two to establish a connection..

housty.

[#6]

@housty interesting configuration! not sure I would have thought of using a local pppoe server to 'fool' the PHO into believing it has an internet connection.

The conventional way to use a PHO as an AP would be to disable its DHCP server, give it a LAN IP in the main routers subnet ( but out of its DHCP range ) and then connect it via a LAN port. Effectively using it a a switch and wireless AP.

UNLESS any of the things below preclude using it this way, then I'd suggest it as an alternative

1) you need all 4 LAN ports

2) you need the PHO to have its own subnet and DHCP server for network segregation

3) you cant live with the flashing orange light on the PHO😀 ( since it doesnt have an internet connection )

That said, I'm going to have a guess (and it really is a guess!)  why the PHO doesnt work in your configuration without the managed switch in the way. I suspect it's down to path MTU discovery (PMTUD to use a FLA😁). When connected directly I don't think its possible to discover the MTU of the link. When connected via the switch , it is probably enabling the path MTU to be discovered. Bear in mind that the PHO is an ISP router and is designed to work in a very specific situation ( connect to  the Bt/Plusnet infrastructure ) as such most of the configuration options are fixed to make life easy for users ( and support ).

I really don't know details of the PHO PPPoE client configuration, and the above really is a guess...

Its a while since I used a PHO but the technical log MIGHT shed some light on why the PPPoE connection isnt establishing.

[#7]

@MisterW All 4 points are indeed factors in my reasoning for using the WAN port as you guessed Interesting thought on the MTU discovery, I'll take a closer look at that.. I played with the idea that they use a VLAN on the WAN and the managed switch was stripping out the tag on its way to my own router but even enabling VLAN 101 on my own router and connecting directly to it still causes the same issue.. I then tried an old Netgear router with the same setup and it works on the PPPoE server directly on my routers port..

It totally has me stomped.. The logs are not giving away to much but I think their seems to be issues with the ACS setup when connected directly to the router.. Anyhow it works but I hate being left in the dark about something that seems simple but out of reach..

I simply assign a private IP address to the WAN on the PHO from the PPPoE server then add a static route on my router to the private IP range behind it via the assigned private IP on the PHO WAN.. 

housty.  

[#8]

I played with the idea that they use a VLAN on the WAN and the managed switch was stripping out the tag on its way to my own router but even enabling VLAN 101 on my own router and connecting directly to it still causes the same issue..

@housty its definitely not VLAN. When the PHO is using the WAN port, it's expecting the modem to do any VLAN tagging/untagging that may be neccessary.

I then tried an old Netgear router with the same setup and it works on the PPPoE server directly on my routers port..

Does that have a setting for MTU (and a default) ? As you've seen, the PHO doesnt have any MTU setting. I just wonder whether it doesn't have a default and relies entirely on path discovery, which of course is fine in it's normal environment.

It totally has me stomped.. The logs are not giving away to much but I think their seems to be issues with the ACS setup when connected directly to the router..

It will have an problem with ACS setup if it's got no PPPoE connection. It's trying to 'phone home' and can't, since there is no internet connection.

Anyhow it works but I hate being left in the dark about something that seems simple but out of reach..

Likewise...

[#9]

@housty Ok, so this intrigued me so much I set about trying...

I have a spare Hub one lying around, my *nix box has a spare NIC and I found a gpl pppoe-server.

Configured it up , set the username/password on the PHO as test@plusdsl.net ( since AFAIK it checks the name format ) , configured the pppoe server for chap authentication. Connected the PHO directly to the NIC and after a couple of false starts to to not telling he pppoe-server to not use the nix passwords and use local authentication, bingo blue light on the PHO and connected.

So it will work without a switch. At the moment the PHO has no internet acces, since I will need to configure iptables to forward from the ppp on the 2nd NIC to the internet

So, thought, does your pppoe-server have an MTU setting and what is it set to ? My server config suggested 1412 which it what I used.

[#10]

@MisterW yeah I also used the open source PPPoE server as a concentrator and it worked with the PHO no problem.. My own router is set to auto MTU discorvery I think it reports something like 1463 not sure but I don't think thats the problem, at this point I'm gathering info to send to Draytek as a bug report, I think this issue is with their current firmware..

housty.

[#11]

Ok, so getting back to this a little more I soldered a makeshift serial cable unto the PHO board and flashed openWrt to it.. Configured the WAN on the switch of the PHO and connected directly to the Draytek without a managed switch and BINGO! it works.. This in my eyes eliminates the fault being with the firmware on the Draytek, something is not normal with the configuration of the PHO.. unfortunately they make it impossible to diagnose the actual issue being so limited in functionality. But now I'm happy that my ECR is not the issue.. 

housty.  

[#12]

Seems like some incompatibility between the Draytek and the PHO, given that it worked for me ( amd you ) with a different PPPoE server. One thing I did notice in my PHO event log, was some 'WAN Auto sensing' messages. I'm assuming that the PHO decides whether to use the WAN port or DSL port by itself, since there is no configuration. How it does that, who knows but maybe that is failing to detect the WAN port being connected when linked directly to the Draytek.

Anyway, glad you have a solution, although I believe OpenWrt on the PHO(HH5A) will have WAN to LAN performance limitations.

[#13]

totally agree, but I'm gonna guess a company like Draytek selling routers that cost 90x that of the Hub One is not the issue, so I'm no longer worried that the ECR has a firmware bug. That said, I wont be keeping openWRT on the PHO just an exercise to rule out the Draytek being at fault...

housty.