et lux in tenebris lucet

In the IPv4 world, router or gateway redundancy is accomplished using a protocol such as VRRP or HSRP. Many of these same routers support IPv6, but not the redundancy factor. Or do they? Fortunately in IPv6 land there’s a built-in feature in the protocol called “router advertisement”, or RA. A router with an IPv6 address on an interface will generate an RA for hosts on the same layer 2 segment. Using this feature, we can create a simple failover setup for IPv6 between two routers. In this example I’m using Cisco routers, but the same concept can be applied elsewhere.

The concept is extremely simple: configure the IPv6 address on both router interfaces as anycast (that is, disable duplicate address detection) and adjust the RA interval and lifetime parameters to your liking. The hosts will pick up the link local addresses from each router/gateway as a candidate default gateway. If one of them fails it will stop sending its respective RA.

The Cisco interface config commands to be applied to the router interfaces are:

ipv6 address 2001:0DB8:107:400::1/64 anycast
ipv6 nd ra-interval 60
ipv6 nd ra-lifetime 300


That’s it! Now you have a basic redundant IPv6 gateway. The obvious drawback to this is recovery time: the failed RA will have to time out on the hosts before it is removed from their routing table. However, you can adjust the RA lifetime on most platforms. This also requires that the hosts listen for RA (which may have implications on an end-user network such as rouge RA). The benefit is that in any case you’ll have simple redundancy using a protocol feature that you may otherwise not have.

You can’t disable autoconf in sysctl.conf because the ipv6 module hasn’t loaded yet, and the ipv6 module loads after /etc/network/interfaces is parsed (thus ignoring your inet6 static section), so here’s how to do static IPv6 addressing with Debian:

iface eth0 inet6 static
    address 2001:0DB8:107:400::a
    netmask 64
    pre-up modprobe ipv6
    pre-up echo 0 > /proc/sys/net/ipv6/conf/$IFACE/autoconf

The gateway will be picked up by listening for router advertisements, as this simply disables the autoconf address. This is ideal for servers.

Debian 6.0 “squeeze”

The IPv6 module no longer exists since it’s now built in (like IPv4), so just omit the modprobe line as such:

iface eth0 inet6 static
    address 2001:0DB8:107:400::a
    netmask 64
    pre-up echo 0 > /proc/sys/net/ipv6/conf/$IFACE/autoconf

Click to embiggen.

The Firearms: Source LAN release party was a great success for such short notice. High five!

Firearms has returned with its first new release after five years! To celebrate this awesome achievement, a Firearms: Source LAN party is being held to play the hell out of it. We will be taking advantage of the awesome bandwidth at rollernet and playing online (you really need at least 8 vs. 8 teams to play LAN only), so everyone needs their own Steam account due to modern day copy protection.

Insults and profanity will be used freely. This is a rated R gaming environment. Bring snacks, drinks, chips, and some cash to chip in for food. A mini fridge is available and we will have bottled water on site. Plan on playing long into the night.

If you can’t make it we’ll most likely be playing online as a group, so join us online. We have set up two public servers just in case: Roller Network Firearms #1 and Roller Network Firearms #2. Friendly Fire may be on or off and will be noted, but we generally prefer to play FF ON.

What you will need to play:

1. See our Firearms: Source page for more info.

Install all of these and you should be good to go. We have plenty of bandwidth to download things the day of. Steam is available for Windows and MacOS, but the Firearms mod is Windows only.

What to bring to the LAN:

You must provide your own Computer, Headphones, Keyboard, Mouse and LCD Monitor. We have power and Ethernet cables; NO WIFI. (We have it, but we don’t use it for gaming.) Use corded mice and keyboards for best results.

A limited supply of keyboards and mice is available on site in case something breaks or is forgotten. Bring a mouse pad or wrist wrest if you can’t play without them (I can’t). We do have plenty of power cords, power strips and Ethernet cables. Leave those at home. Headphones are an absolute must with multiple people playing in the same room. Microphones are optional, but useful to talk to teammates online. LCD monitors are required due to power, weight, and heat limitations.

HAVE FUN and welcome to Firearms!

Local Mirror Copies:

• See our Firearms: Source page for mirrors.

I don’t play video games very much. I can name the games I thoroughly enjoyed (Bungie’s Marathon, Myth, Myth II, Starcraft, Deus Ex, Knights of the Old Republic, Mass Effect, Half-Life, Half-Life 2, Portal, just to name a few). However there is one multiplayer Half-Life mod that was the staple of LAN parties and one of my favorites: Firearms. It’s probably the only one I played online, and still have occasionally played to this day when I have time.

When the Source engine came out there was lots of talk to a successor for Firearms on Source. Some of the original team went to work on World at War and there was even a Firearms 2. There were accusations of stealing and other drama, but the only team that actually ended up with a release product was the Firearms:Source team. All the rest went defunct, lost interest, or disbanded.

I’ve always particularly enjoyed the “push” mode where you have to capture points/flags in order and hold them. Your reinforcements will always come from your base (none of this magic spawning at the forward point or arbitrary locations) so it gets progressively harder the further away you get. I also love to play with FF on. FF off is too boring.

On July 23 2010, Firearms will return.