Locality Switch

There comes a point when you no longer can rely on a single ADSL connection for your network. Things start getting too hectic through that one little connection running down some 100 year old copper pair, the modem freaks out and dies on a regular basis, and then people start screaming out for a fix.

At Cumberland Community Radio, a sub-metro community radio station in Sydney, we had exactly that problem. We had become very reliant on our connection to the internet, and when it didn’t work, I found out pretty quickly and frequently. It just wasn’t acceptable to have your news feed, internet streams and VoIP fall over so frequently.

We needed a fix, and fast!

A second ADSL connection was sourced with a different provider, but to manage these two connections we needed some fancy piece of hardware. Something smart enough to work out what both connections were doing, fix any issues, and route the traffic in the right direction. We needed a router/firewall with dual-WAN ports.

I initially expected to spend quite a large sum of money on a piece of hardware like this. But thankfully I didn’t have to. The model we picked was a DrayTek Vigor 2910. This little box cost less than AU$280, from OzCableGuy. These guys were able to get the box to us in less than a week, and that was paying with Bank Transfer, too.

Setup was fairly simple. In fact, if you know the jargon of LANs, WANs, and all that jazz, it’s easy. If you don’t, then I suggest you learn that aspect of things before you buy this box. There’s defiantly an expectation that you aren’t a beginner when trying to set up this piece of hardware.

Configuration is via web interface, which can be a little buggy at times. There isn’t much validation of input, so it will sometimes accept invalid input you mistakenly gave it, and you then are left wondering why something isn’t happening as expected. It’s little things like that which tripped me up the most.

The first thing I did was get the two WAN links happening. For this to work, you need to turn each of your two modems into ‘dumb’ modems. This means that the box which interfaces your phone line with the network dosen’t handle any sort of router functionality. In fact, it shouldn’t even handle any PPPoE authentication. The term used to describe this is ‘bridge mode’.

The two cheap consumer modems I had were a little trickier than expected to get into bridge mode, but a quick look at the manual sorted that out. It’s always that one checkbox you miss that trips you up, right?

Once you’re modem is in bridge mode, the DrayTek Vigor2910 handles all of the PPPoE authentication. The beauty of this arrangement is that if your modem disconnects, the DrayTek picks up on it really quickly, and it’s reconnected before you know it. This would be one of the best parts we’ve experienced so far.

Setting up firewall rules and port forwarding was no-nonsense, and done in a similar fashion to ordinary modem/router devices, but with extra functionality. There is also load balancing policy, so you can choose certain services to go through certain WAN ports if that is desired. There are also features available such as URL-filtering, VPNs, and all that good stuff. I haven’t set all of that up yet on this particular box, but if there is a need in the future, we know it’s there, ready to go!

Overall, the DrayTek2910 has been a solid performer, and I would defiantly recommend it in the future for similar situations.