I installed an Internode NBN HFC service in an apartment a few months ago. It comes with a Huawei HG659 router, attached to the NBN standard issue Arris HFC cable modem.

I really don’t like that router. Its got some negative characteristics  – including it having a DHCP server that can get itself confused and conspire to keep handing out a conflicting IP address on the active network. I also much prefer using Apple Airport Extreme base stations for WiFi networking rather than the built in stuff in routers of that ilk (lets call them ‘low cost and cheerful’) – especially when I’m running multiple WiFi base stations (as is the case in the site concerned).

I’ve had great success in another site using Internode NBN via Fixed Wireless by just configuring the PPPoE client into the Airport Extreme and plugging that straight into the incoming connection from the Fixed Wireless NTD. That worked like a charm, and eliminated a similarly ‘cheerful’ router in that circumstance. However this simple approach just didn’t work on the NBN HFC connection – configuring the PPPoE client in the Airport Extreme and plugging it into the Arris HFC cable modem directly lead to no joy.

Each NBN ISP has some choice over how the HFC based NBN connection gets deployed to their customers.  Some digging turned up the data point that the Internode service delivered via the NBN-Arris HFC modem is implemented as two ethernet VLANs, with VLAN 1 delivering the bundled VoIP fixed line phone service and with the Internet service delivered over VLAN 2.

There is no way to configure the use of an upstream VLAN in the Airport Extreme – it expects the PPPoE frames to turn up natively (with no VLAN tagging).

Some more digging and the solution emerged, namely to keep the Huawei HG659 in the picture but use it merely as an ethernet VLAN decoder. In that role, its job is so simple that it can do it without losing the plot.

and… it works (yay!)… but there are – of course – wrinkles 🙂

The steps involved should have been this simple:

• Configure the HG659 using its wizard to ‘connect with another modem’. This is what the HG659 uses as its description for bridging the incoming VLAN to the local LAN ports.
• Keep the HG659 WAN port connected to the Arris HFC modem (obviously)
• Cable the Airport Extreme WAN port into one of the LAN ports of the HG659
• Using the Airport Utility on a Mac, configure your PPPoE account details into the Extreme (Internet tab, select PPPoE and then fill in the username and password, leave the ‘Service Name’ blank)

However, this is what I also had to do (all in the Airport Utility)…

• The DHCP IP range configured into the Airport Extreme needed to be changed (at least, I needed to change it, to make things work – YMMV). I switched it from its default of the 10.x range, and instead set it to use NAT on the 172.16 range (Network tab, Network Options button, IP v4 DHCP Range drop-down)
• I had to turn off IPv6 entirely to avoid an ‘IPv6 Relay’ error coming up (Internet tab, Internet Options button, Configure IPv6 drop-down set to ‘Link Local Only’).
• Turn off ‘Setup over WAN’ to avoid an alert coming up on the Airport Utility and the base station light flashing amber (Base Station Tab, clear the “Allow Setup over WAN’ check box). The point here is to explicitly disable the capacity for the Airport Extreme to be accessed (by the Airport Utility) over the WAN path. That’s definitely something I want disabled. My only issue here is that I’m surprised this checkbox is actually on by default in the first place!

One more bit of collateral damage here is that I probably can’t access the free VoIP phone service delivered over HFC VLAN 1 and out via the analog port on the HG659. I don’t care, I wasn’t interested in using it in the first place. It may well be the case that some cunning manual configuration of the HG659 could make that work (too) – but I really don’t care about it – so I just haven’t tried.

The one silly thing left out of all of this is that I didn’t get rid of any physical devices in the process, so I have this conga line of three hardware devices between the cable modem wall plate and the user devices in the site – the Arris HFC modem, the HG659 (now as a VLAN 2 decoder box only) and the Airport Extreme (as the site router plus central ethernet switch to some downstream Airport devices).

Speed tests are just as good as they were already, with downstream rates testing reliably in the mid 90’s and upstream in the high 30’s – pretty darned good (especially through that crazy hardware conga line) on a 100/40 Internode connection. Importantly the issues I had with the HG659 router and DHCP are gone.

Other notes:

• The Internode NBN HFC service is in fact deployed on TPG infrastructure, so the above should apply equally to a ‘native’ TPG NBN service too. This also explains why the IPv6 doesn’t work (sniff).
• The VoIP service should be capable of still being used, perhaps with some custom configuration of the HG659, and I may try to find a way to make that work just for the sake of the challenge
• A router such as a FritzBox which is capable of VLAN decoding on the WAN port should be able to be used to deliver the Internet service directly via the Arris HFC modem without using the HG650 at all (eliminating one device). Its also possible the FritzBox may be smart enough to support logging in to the voice service via WAN VLAN 1 as well … and that is something to try out another day…!

Arris HFC Modem

Huawei HG659

Apple Airport Extreme

Postscript: There is another approach to the removal of the Huawei device from the critical path that has been pointed out to me on another blog – here. This won’t work with the Airport but it is a way to allow a Fritzbox or a high end Billion or another router with WAN port VLAN support to be used for the Internet path instead of the HG659, leaving the HG659 functional as well – in parallel – to provide the voice port service that is bundled in with the Internode NBN HFC service. The benefit here is for people who do want to use that bundled voice service while also removing the HG659 from the critical path in Internet access terms. While it does need yet more hardware (an ethernet switch) – its a really creative and effective answer that might be very helpful to others to know about!