I had a connection with BeThere with my BeBox in bridged mode, with a Mikrotik router behind it. My connection got migrated to Sky when Sky bought the Be business. I lost all but one of my static IPs, but more importantly, bridged mode stopped working. I rung Sky and their helpful advice was that they don’t support multiple static IPs, and they don’t support bridged mode. They said I’d find instructions on how to run bridged mode in the forums, but those instructions simply aren’t there (not to any working degree anyway). Given they’d effectively broken my entire DSL connection and had no solutions to proposed, I asked them whether I should simply take a MAC code and my business elsewhere. The guy on the other end of the line was clearly used to this from Be customers and had no issue with this. However, first I decided to see whether I could fix it.

The problem here turns out to be that Sky only do PPPoA (not PPPoE), and don’t support what used to be bridged mode in the BeBox. The BeBox is in fact (in my case anyway) a Technicolor TG582n, and it is (just about) possible to get this working in a sort of bridged mode, by using a little known feature of the TG582n to bridge from PPPoA to PPTP.

For the benefit of Sky customer service: I know supporting PPPoE as well as PPPoA might have been a minor bother. However, you could relatively easily have worked out how to do this bit for Be customers. And no doubt you could also easily have worked out a way of putting the Sky box you shipped me into some form of bridged mode too. How many customers were you intending to lose?

Anyway, here’s how you do it.

Step 1:

Connect your TG582n direct to your computer and remove the ADSL connection.

Reflash your TG582n with a sensible firmware image. Some helpful person might supply you with a copy of the software. If you have Windows, there is a software update tool. If you don’t, it will tftp boot. Mine doesn’t on power up, but the ‘software upgrade‘ command works from the administrator CLI. I have a DANT-1 board. Apparently there are different board versions needing different firmware. The main thing is to remove the Be firmware.

Step 2:

Restore the factory settings on your TG582n. Do this by ‘telnet 192.168.1.254‘ (username ‘Administrator‘), then type:

:system reset factory=yes

This will reset your password to the default for the firmware (possible to an empty password, possibly to your serial number).

Step 3:

Now put your TG582n into PPTP bridge mode. To do this, follow the instructions here. In short, log back in and type:

:ppp flush
:eth flush
:atm flush
:atm phonebook flush
:atm phonebook add name=vpi0vci38 addr=0*38
:service system modify name=PPTP state=enabled
:pptp flush
:pptp profadd name=vpi0vci38 encaps=vcmux
:ipqos config dest=vpi0vci38
:wireless ifconfig state=disabled
:saveall

Note: I am told that previous editions of the firmware may have had an issue where on reboot the ADSL interface is not correctly initialized. Hence whilst the config will work, it won’t survive a reboot. The workaround is to put in a fake routed connection to a non-existent VPI/VCI combination. I’m running 10.2.6.9 and it does not suffer from this issue.

Step 4:

Connect the TG582n to the Mikrotik and the ADSL line. Number the raw ethernet interface (I used port 2 but I don’t think it matters) to be on the same subnet as 192.168.1.254 (the Mikrotik).

Step 5:

In order for the TG582n PPTP connection to connect successfully, the session must have a phone number entry of ‘vpi0vci38‘. It is not obvious how to do this with a Mikrotik, but here’s how. Go to the PPP menu, click ‘Profiles’ and add a new profile (I couldn’t get anything but a name of ‘Profile1‘), and under ‘Address List’, enter ‘vpi0vci38‘.

It should look like this:
Mikrotik PPP panel
Mikrotik PPP panel

Step 6:

Create a new PPTP client interface (I called it ‘pptpsky‘). Make it ‘connect to’ 192.168.1.254, and use the above profile (where it says ‘default‘ select ‘profile1‘ instead). Do not select ‘Add default route’ as Sky sends a bogus default route (or more accurately seems to negotiate a bogus endpoint), just to be unhelpful. Use the credentials of your ISP, i.e. username ‘install@o2broadband.co.uk‘ and ‘password‘.

As the PPTP IP connection runs between the Mikrotik and the TG852n only, you can set the MTU and MSS to 1500 bytes quite safely. Though you’ll get fragments over the half metre of ethernet cable, you will be able to move full unfragmented ethernet frames over the WAN.

It should look like this:
Mikrotik Interface panel
Mikrotik Interface panel

Hopefully the connection should now go into a ‘running’ state.

Step 7:

Insert a manual static default route, using route ‘0.0.0.0/0‘ and for gateway enter the interface name of the PPTP interface. In my case that was ‘pptp-sky‘. No, it’s not obvious you can do this, and yes I thought it wanted an IP address too.

It should look like this:
Mikrotik Route panel
Mikrotik Route panel

That was sufficient to get my connection running again. Good luck!