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Thunderbird LDAP Address book certificate errorsWednesday 28th December 2011
An LDAP address book in Thunderbird is a great way to have a centralised list of e-mail contacts. This way you only have to maintain one list (done outside of Thunderbird) for multiple computers etc.

I recently set one up but was presented with an SSL error when trying to connect to my LDAP server through a PuTTY tunnel:

ssl_error_bad_cert_domain

This is because the hostname I was connecting to was "localhost" and not the actual server's name (due to the tunnel).

When viewing a web-site in Firefox you'd just click Add Exception, but there is no option for this here. Do not fret though, as you can add an exception manually.

Tools - Options - Advanced - Certificates - Servers

Click on Add Exception, and then type in the address and port that your tunnel is setup to, excluding any protocol. e.g.

localhost:636

Hit Get Certificate and then click Confirm Security Exception.

You may need to restart Thunderbird to get this to kick into life.


Dolby Digital with Audigy 2Tuesday 20th December 2011
As a follow up on my bit on using my AV receiver with my Creative SoundBlaster Audigy 2 ZS. I have now received the mono mini-jack to RCA adapter. Using a standard set of phono/RCA leads I connected one channel up to the digital input on my AV receiver and enabled the Creative Dolby Digital Live pack for my sound card.

A few hours later of plugging in speakers reinstalling drivers and head scratching I found the "Direct" button on my receiver and turned it off. It all then sprung into life.

CMSS works in 3D, surround sound in games like Battlefield 3 works fine, Dolby Digital DVD works fine, EAX works fine with the usual Alchemy tricks.

What doesn't work is the volume. Or in fact, any of the Windows-wide settings. So volume, and tone settings are long gone. You have to rely on your external amp to control the volume - and not many give you good control over the EQ - especially on an AC3 signal.

Still, it now positions me to lose an amp, and upgrade a set of speakers as my bass is correctly filtered out now to the sub.


Soundblaster Audigy 2 ZS surround soundSaturday 10th December 2011
I never felt I got the best out of my now old, Creative Soundblaster Audigy 2 ZS. It's been great for games, and I have for most of my life used a 4.2 setup. That is, I've got two sets of 2.1 speakers, and set them up as front and back speakers.

The internal amp in a 2.1 setup deals with the high-frequency cutoff for the sub, and passes the bass bits to the subwoofer and the rest to the speakers. This means you get the full whack of sound all around.

I've slowly upgraded my computer speakers over the years, and I now have an old A/V receiver on the front with some old Tannoy book shelf speakers. But with surround sound support in my receiver it feels a little silly having a back set of speakers independently driven.

The Audigy 2 ZS allows you to connect the discrete channels for a 5.1 system. There are three outputs on the back. One deals with stereo front, the next stereo rear, and finally subwoofer and centre speakers. You can even start chucking the TRRS cables at the card to get more discrete channels (6.1/7.1) - just use the old composite A/V minijack cables and figure out which channel goes to what (I think sub is left, centre is video).

Alas, things aren't as easy as just plugging in your sound card to an AV receiver, the main problem is computers don't produce "Dolby Digital" or any other encoded signals, they produce discrete channels. Unfortunately for me it all goes wrong with the subwoofer. As there is no discrete LFE channel getting pumped out of games and your audio player, that channel stays dead; add this with a receiver that is expecting a LFE signal, the sound is suddenly flat.

In summary, after wrestling with working out which output does what, setting it all up through a receiver, you're going to get worse sound than before.

There is now a program called Dolby Digital Live, which at the princely sum of 2 isn't going to break the bank. This will take the output of your computer and bundle it up into a Dolby Digital signal that can be connected to your amp. Unfortunately Creative didn't seem fit to extend the same processing to the analogue outputs, so it provides bugger all benefit.

The Audigy 2 ZS does though have a digital output on it. So I've paid yet more money (1), to order a mono miniplug to RCA adapter, which I'm lead to believe will allow me to use the digital output from my computer and plug it into my receiver and everything should magically work. The proof of course is in the pudding, we shall see...

Ultimately I would like to see a soundcard that provides this sort of intelligence seemlessly. I feed it an audio signal, it's clever enough to tell that there is only 2 channels, so has the frequency cut over dealt with here. It should be able to provide hardware encoding of digital signals on-the-fly in realtime. Maybe Creative's latest Recon3D might offer some of this, but I doubt it and I'm hearing rumours it doesn't support 3D games from the outset. Go figure.



IPv6Friday 9th December 2011
So as IPv6 is looming on the horizon I decided it was about time I started implementing it at home to see what works.

Having an ISP that doesn't provide IP6 addresses means I can't test anything on the Internet, but I have enough gumph internally to make a start.

I started by assigning my openSUSE server an IPv6 address. For some reason YaST only has one box for an IP address, but you can assign additional extra addresses. This bit happily took an IPv6 address.

If you're on an internal LAN then you can use "site-local" addresses, which start with FEC, FED, FEE or FEF. You can also use "link-local", but as I have multiple networks that will want to communicate, I opted for the more flexible site-local. As I only have a handful of devices connected I have little interest in the zillions of addresses that can be used, so I opted for a simple "FEF0::1000", it seemed like a good random place to start, and fairly easy to remember.

I then setup "dhcpd6", but editing /etc/dhcpd6.conf and set it to allocate on the subnet fef0::/64, dishing out addresses from fef0::2000 up to some other large number.

Powering on a Windows 7 client, it picked up the address fine, no fuss here.

The next step is DNS. I have an internal zone, so I need to register my server's hostname against DNS with an AAAA record (IPv6 equivalent of an A record). Having DHCP update DNS automatically when a new device registers means I don't have to worry about adding anything else in by hand. A reverse lookup zone is also required, this is a bit messy because you have to write out the subnet in dotted format: 0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.f.e.f.ip6.arpa. I lopped 4 of the 32 digits off the front so the zone will cover the same subnet as my DHCP server (I think).

YaST takes care of updating reverse lookup entries based on the forward lookups, so no more effort required here.

Next I will be making sure all the name resolution and such is working properly, and seeing what devices work (printers, phones and such). Then I will be moving onto VPN and my other networks to see if I can the whole thing working in a similar fashion to my IPv4 world.

Things won't get really interesting until my ISP starts dishing out IPv6 addresses.


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