Life’s been busy for the past few months, so excuse the lack of posts. One reason for this is that I’ve moved house. Virgin were supposed to install a cable modem on November 11th, but at the time of writing currently have my install on hold (more on that in the future). As a result when we actually moved in mid-December there was no broadband available. I’d noticed Currys were doing a deal on an EE 4GEE WiFi Mini - £4.99 for the device and then £12.50/month for 20GB on a 30 day rolling contract. Seemed like a good stopgap measure even if it wasn’t going to be enough for streaming video. I was pleasantly surprised to find it supported IPv6 out of the box - all clients get a globally routed IPv6 address (though it’s firewalled so you can’t connect back in; I guess this makes sense but it would be nice to be able to allow things through). EE are also making use of DNS64 + NAT64, falling back to standard CGNAT when the devices don’t support that.

All well and good, but part of the problem in the new place is a general lack of mobile reception in some rooms (foil backed internal insulation doesn’t help). So the MiFi is at the top of the house, where it gets a couple of bars of 4G reception and sits directly above the living room and bedroom. Coverage in those rooms is fine, but the kitchen is at the back of the house through a couple of solid brick walls and the WiFi ends up extremely weak there. Additionally my Honor 7 struggles to get a 3 signal in that room (my aging Nexus 7, also on 3, does fine, so it seems more likely to be the Honor 7 at fault here). I’ve been busy with various other bits over the Christmas period, but with broadband hopefully arriving in the new year I decided it was time to sort out my UniFi to handle coverage in the kitchen.

The long term plan is cabling around the house, but that turned out to be harder than expected (chipboard flooring and existing cabling not being in conduit ruled out the easy options, so there needs to be an external run from the top to the bottom). There is a meter/boiler room which is reasonably central and thus a logical place for cable termination and an access point to live. So I mounted the UniFi there, on the wall closest to the kitchen. Now I needed to get it connected to the MiFi, which was still upstairs. Luckily I have a couple of PowerLine adaptors I was using at the old place, so those provided a network link between the locations. The only remaining problem was that the 4GEE doesn’t have ethernet. What it does have is USB, and it presents as a USB RNDIS network interface. I had a spare DGN3500 lying around, so I upgraded it to the latest LEDE, installed kmod-usb-net-rndis and usb-modeswitch and then had a usb0 network device. I bridged this with eth0.1 - I want clients to talk to the 4GEE DHCP server so they can roam between the 2 APs, and I want the IPv6 configuration to work on both APs as well. I did have to change the IP on the DGN3500 as well - it defaulted to 192.168.1.1 which is what the 4GEE uses. Switching it to a static 192.168.1.2 ensures I can still get to it when the 4GEE isn’t active and prevents conflicts.

The whole thing ends up looking like the following (I fought Inkscape + Dia for a bit, but ASCII art turned out to be the easiest option):

/----------\       +-------+       +--------------+            +------------+
| Internet |--LTE--| EE 4G |--USB--|   DGN3500    |--Ethernet--| TL-PA9020P |
|          |       | MiFi  |       | LEDE 17.01.4 |            | PowerLine  |
\----------/       +-------+       +--------------+            +------------+
                       |                                              |
                      WiFi                                            |
                       |                                              |
                  +---------+                                         |
                  | Clients |                                     Ring Main
                  +---------+                                         |
                       |                                              |
                      WiFi                                            |
                       |                                              |
                  +--------+            +----------+            +------------+
                  | UniFi  |--Ethernet--|   PoE    |--Ethernet--| TL-PA9020P |
                  | AC Pro |            | Injector |            | PowerLine  |
                  +--------+            +----------+            +------------+

It feels a bit overly twisted for use with just a 4G connection, but various bits will be reusable when broadband finally arrives.