My ADSL provider Andrews & Arnold have provided me with a /48 IPv6 subnet, which seems somewhat wasteful at 2^80 addresses (throw that in your calculator) but certainly useful for testing nevertheless. Whilst slowly getting my head around the task that is variable-length subnetting of IPv6 ranges – painful at best – I decided to just throw in a /64 subnet and set a static gateway address on m0n0wall‘s LAN interface to see if it would ‘just work’.

The result, is a working IPv6 LAN by simply enabling autoconfig from the m0n0wall box and telling Ubuntu’s Network Manager to use it. Et voila:

teh@desktop:~$ ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:01:29:fc:37:1d
inet addr:81.187.xxx.xxx Bcast:81.187.xxx.xxx Mask:255.255.255.240
inet6 addr: 2001:8b0:ff87:1:201:29ff:fefc:371d/64 Scope:Global
inet6 addr: fe80::201:29ff:fefc:371d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1616524 errors:0 dropped:0 overruns:0 frame:0
TX packets:2224946 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:277202062 (277.2 MB) TX bytes:519498762 (519.4 MB)
Interrupt:18

You’ll notice that the last 80 bits of my IPv6 address on this host were assigned via autoconfig, using part of my MAC address (the part that doesn’t correspond to a certain manufacturer, IIRC) as well as some randomly-generated bits, too.

And to make my night, ping6 worked straight away, too:

teh@desktop:~$ ping6 2001:08B0:FF88:0001::1
PING 2001:08B0:FF88:0001::1(2001:8b0:ff88:1::1) 56 data bytes
64 bytes from 2001:8b0:ff88:1::1: icmp_seq=1 ttl=64 time=3.81 ms
64 bytes from 2001:8b0:ff88:1::1: icmp_seq=2 ttl=64 time=0.130 ms
64 bytes from 2001:8b0:ff88:1::1: icmp_seq=3 ttl=64 time=0.132 ms

--- 2001:08B0:FF88:0001::1 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 0.130/1.358/3.813/1.735 ms

Now to plan how I’m going to roll this out at work…

Even so, due to the impressive compatibility of the Sony Ericsson K800i and Linux, and the subsequent lack of the same DHCP/CDC USB Ethernet adapter functionality in the K850i, I thought it’d be quite cool to see if the K800i could be configured as a back-up WAN interface within m0n0wall.

So I fish my K800i (now retired, although I wish it wasn’t) out of its resting place, find a USB cable, and plug it into the back of the m0n0wall machine. No new interface appeared on the ‘assign interfaces’ page, so I restarted it. Still no new interfaces. Upon checking the kernel messages in the log, I found these lines pertaining to the CDC USB Ethernet device:

Jan 4 20:28:06 kernel: device_attach: cdce0 attach returned 6
Jan 4 20:28:06 kernel: cdce0: could not find data bulk in
Jan 4 20:28:06 kernel: cdce0: Sony Ericsson Sony Ericsson K800, rev 2.00/0.00, addr 2

Which, as a Linux geek, confused me somewhat. Google turned up a number of results for ‘cdce0′ problems or ‘attach returned 6′ regarding various other drivers, but only one really addressed the issue in particular, albeit for a much older SE phone. You’ll notice that there haven’t been any replies, either.

A former colleague pointed me in the direction of a patch that was submitted around October 2008 which enables the proper handling of the CDC USB device within the Nokia N80. Hopefully it should help, but it may be some time before the patch filters down to m0n0wall.

This is just one of those times when I wish I’d followed the world of software development a little more.

So when the K850i came out, I was quite eager to get my upgrade. And so far there’s been only one real drawback to it, that I’ve found: using it as a modem.

When I first moved into my current abode, I didn’t have any ADSL for a few weeks. Predictably one can steal some wireless broadband, or one can attempt to use some form of mobile broadband. Before signing my life away for a few months, I decided to test my phone (which at the time, was the K800i) with Ubuntu. To my sheer delight, the phone presents itself as a USB Ethernet adapter, and Ubuntu’s network-manager simply sent a DHCP request and received an ACK. No messing about here: I had 3G broadband within 5 seconds of plugging the USB cable in!

So obviously when I attempted the same trick with my K850i, I was really quite dismayed to find that you can’t do this any longer. The USB Ethernet device is there (grep -i CDC /var/log/messages) but for the life of me, I cannot find a way to obtain a DHCP lease via the usb0 interface.

Yes, it works perfectly (and with HSDPA speeds, thanks to my city-centre location) if you use wvdial or one of its GUI front-ends (gnome-ppp worked well) and I’ve been able to connect like this..

But I can’t understand why the Sony Ericsson engineers would want to remove such a simple mechanism in favour of the greatest faff-about in history. I’d be interested to hear from anyone that’s managed to get this working.. Although I fear by the time I get an answer, I’ll be back on some ADSL goodness: HSPDA is alright in a pinch, but T-Mobile UK’s data network seems so heavily sensitive to peak times (I suspect insane levels of contention) and the latency is atrocious. Half a second? Ugh. That’ll be the Deep Packet Inspection they do…

I’ve spent the evening getting my RoutITX project off the ground and into service. But to do this, I needed an ADSL2+ modem. So, rather than persist with using my Netgear DB834GT, I thought I’d try out a P660R-D1 from Zyxel. Simple little thing, only about £25, and claims to be able to do bridging to its (single) Ethernet port.

Can it hell. I’ve tried everything I can; it can sync the DSL to a lovely speed, but it can’t get any further than that.

What I’d like is a nice, small, cheap, ADSL2+ modem (preferably including Annex M) that does a perfect bridge, with good reliability and performance.

There’s got to be one out there? I’d love to know.

ZFS, for those of you who aren’t familiar, has really shaken-up the world of file systems recently, as it changes almost everything that we perceive about a modern-day file system. On top of these fundamental changes (which I won’t go into detail about here) the ZFS developers have added some really neat features, such-as zero-cost snaphosts, replication between machines, RAID-Z, and quite a lot more.

It’s the promise of these features that has prompted our change over to a NAS-based storage system. Given that we can completely replace our current system of identical live/backup hosts, with slow backup scripts and drbd mirroring, it’s quite promising to think what we can achieve.

The problem is transport. And keeping fast transport. Given the extra overheads of IP/NFS that NAS brings (weighted against the benefits given ZFS over the more efficient use of raw disks in a SAN) it’s been deemed that a single gigabit link just won’t be up to the demanding task. The problem is that once you decide to cross the gigabit ‘barrier’, your costing simply spirals uncontrollably skyward.

There are a few options available to achieve a decent throughput:

• Multiple, bonded (802.3ad) gigabit links – cheap-ish, but some multiport adapters really aren’t cheap.
• 4Gbit FibreChannel – readily available Solaris support, but over-shadowed by 10GigE/Infiniband and requires costly HBAs with extremely expensive XFP/SFP+ modules.
• Infiniband (SDR 4x, 10Gbit) – really, really cool, but there’s a huge lack of support in Solaris.
• 10Gigabit Ethernet – very new, and switches are extremely expensive (laughably so, think $20,000 for a 24-port switch + Gbics!) mainly due to the lack of 10GBase-T support (meaning we need 10Base-CX4 or some Fiber-based solution.)

So what’s the answer? We’re not a Fortune 500 company, so most of this is still out of reach. On top of it all, we need to rely on Solaris for ZFS – an operating system which seems to have very little manufacturer support, despite its presence in the cluster and virtualisation markets. Sun’s Hardware-Compatibility List is almost devoid of recent Infiniband/10GBase-T adapters, particularly in PCI-E interconnect guises.

It wouldn’t be so bad if some manufacturer had thought to release a small-scale, 8-10 port 10GigE, 10GBase-T switch. They just don’t exist.. At present, it’s quite likely that we’ll have to dump the idea of a switched fabric altogether, opting instead of multiple point-to-point links.

It seems we’re either just a few years ahead of ourselves, or really, really out of our depth.