On Sunday, August 22nd 2010 there will be a outage of the mailsystem from 13:00 to 17:00. The reason is the installation of a new SMTP system. I ‘am migrating from Courier-MTA to Exim4, ultimately bringing some new features to the mail system like Sieve, greylisting and two-stage-spamassassin-checks.
Downtime is intended to be kept at a minimum and retrieval of mails through IMAP/Webmail will be unaffected. Incoming and outgoing mails will be delayed though.
There is a guy named Felix Stoffel somewhere in Switzerland who calls himself a “communications analysts” and now he released a press text on primes and their determinism. The headline sounds great:
Primes finally completely defined
(translation by Google)
Photo by mainblancheThe text is currently only available in German but after reading it, it turned out that he only reinvented the Sieve of Erathostenes, attributed to a ancient Greek mathematician who is never mentioned anywhere in the whole text.
The first half of the press text tries to use complicated philosophical language and overly complex mathematical constructs to irritate the reader while the second part drifts off into babbling about ore harvest on the moon and quantum-gravity.
Dear Felix Stoffel, whatever a “Kommunikationsanalytiker” (ger. for communications analysts) is to you but if that’s what their output is, selling ancient inventions as their own, I’ll put your job title on my esoteric-wackos list, next to the Orgon-chamber-manufacturer.
Anyone who is really interested in primes and their nature should start at Wikipedia.
Update: According to his profile, the author of this press text owns a PhD degree from the Commonwealth Open University which is listed as an unaccredited school by government authorities and is suspected of being a degree-mill.
DENIC messed up their DNS servers today rendering most of the domains in .de unreachable. In technical terms requests to their servers either timed out or returned a NXDOMAIN answer, which states that the domain does not exists.
Kristian Köhntopp came up with the following URL to the DENIC homepage:
http://www.denic.de/typo3temp/pics/i_64bbbffdb3.jpg
I think if this is what DENIC considers to be a domain it’s really astonishing that .de did not break earlier 
Ironically, this site may not be reachable right now.
Because of this: $90 for a simple Plug-in? You must be kidding!
At least this is the final prove we all needed to realize that the bean-counters have taken over and the techies are leaving. Reminds me of a sinking boat. At least we at the MUG dropped plans for an Oracle cluster in favor of a PostgreSQL cluster.
The performance comparison between Oracle and PostgreSQL was absolutely dominated by the second one. A paper on this topic (only in German by now) will be published later this year.
For the last week I was without IPv6 connectivity on all of my client machines. Running traceroute6 from the tunnel-end-point worked fine, although i could not get any further than to the first hop from the clients. The IPv6 prefix is advertised over a IPv4-OpenVPN from the server running the tunnel. I dug really deep into it, turning off all netfilter rules to eliminate the packet filter from the possible troublemakers but all my packets were still dropped at the tunnel. Routing was set up correctly, I could reach all IPv6 sites from the tunnel itself.
After having spent almost half a day on this problem I remembered that I applied for a Hurricane Electric tunnel a month ago so I decided to remove the go6 client from the server. Setting up the new tunnel was quite easy, as i could just place it’s configuration inside /etc/network/interfaces (applies to Debian):
auto ipv6-he
iface ipv6-he inet6 v4tunnel
address 2001:470:1f14:804::2
netmask 64
endpoint 216.66.84.46
local 193.170.104.5
ttl 255
up ip -6 route add default dev ipv6-he metric 2
up ip -6 addr add 2001:470:1f15:804::dead/64 dev br0
down ip -6 addr del 2001:470:1f15:804::dead/64 dev br0
down ip -6 route del default dev ipv6-he metric 2
This gave me a 64 prefix to advertise to my clients on interface br0, a bridge consisting of a physical interface and the OpenVPN tap device. I created the file /etc/radvd.conf:
interface br0
{
AdvSendAdvert on;
AdvLinkMTU 1280;
AdvDefaultPreference low;
prefix 2001:470:1f15:804::/64
{
AdvOnLink on;
AdvAutonomous on;
};
};
After starting radvd I got full IPv6 connectivity back, this time through Hurricane Electric. The update to the AAAA records for uni.fladi.at will take it’s time to get distributed across DNS.