Exim, IPv6, and lots of email errors

Since I eventually moved the email server (exim) over to the server blastoise, it’s been giving me grief. Something along the lines of rejecting emails because it wasn’t allowed to relay mail through itself, even though I’d actually told that it was allowed to:

hostlist   relay_from_hosts = <; localhost ; 178.79.130.8

However, blastoise is IPv6 capable, and prefers that over IPv4, and because all the settings point to "mail.helpmebot.org.uk" which points to both 178.79.130.8 and 2001:470:1f09:1213::2, it was skipping "localhost", and preferring IPv6, which wasn't listed, hence the nice error log was filling up with messages like this:

220 helpmebot.org.uk ESMTP Exim 4.71 Sat, 19 Feb 2011 17:50:24 +0000
EHLO blastoise.helpmebot.org.uk
250-helpmebot.org.uk Hello blastoise.helpmebot.org.uk [2001:470:1f09:1213::2]
MAIL FROM:
250 OK
RCPT TO:
550 relay not permitted

Hopefully the problem is fixed now, with the correct configuration (adding the brand new metapod's IPv4 and IPv6 addresses):

hostlist   relay_from_hosts = <; localhost ; 178.79.130.8 ; 178.79.155.110 ; 2001:470:1f09:1213::2 ; 2001:470:1f09:1581::2

In case you were wondering, the default separator for lists in Exim's config file is :, which causes "issues" with IPv6 addresses. A quick google told me to prepend <; to the beginning of the list, which changes the separator from : to ;, which doesn't cause a problem with IPv6 addresses. :)

Sometimes I really don't like it when that sort of thing happens... configuration stuck in a dark dusty corner somewhere breaks because something random changes like adding an IP to the system.

Getting drunk is not good for work the next day…

So, for a quiet night with a couple of drinks, work the next day, I thought why not? It’s only gonna be a couple of drinks, and there’s not gonna be that much to do the next day.

Urgh, not doing that again. I don’t think I’ve thrown off Thursday night’s hangover entirely yet.

So, a nice quiet night turns bad when you move off the cider and onto the vodka. When it becomes a good idea to move to another bar, get more drunk, then move on to a club, things can go downhill quickly.

So, me and a bunch of my straight(er :P) friends, and we happen to end up in CC Blooms (a gay club) – I’m still in amazement about how comfortable some of them were with some of the dancing that was occurring :P

And then there was the karaoke. Singing along to Snow Patrol’s Run, at the top of your voice without a mic is a bad thing. Sore throat Friday, No voice Saturday.

It was the Carol Concert that went the most pear-shaped though – being ridiculously hung-over and trying to op a sound desk when there’s a slight issue of the next channel being at max with something like static with the gain at minimum. No off switch for the channels. Hungover. Yeah, you guessed it, I nearly deafened everyone in the room. Including the principal of the university. :S

So, I had the sound desk to pieces after that, dunno what was wrong, but wired it up slightly differently, and took out some kit that was unneeded. The problem seemed to disappear, so meh.

The Christmas Party followed later that day, and with the freshly DMX’d UV LED thing pointing at the white christmas tree from the red party, I was happy that not much could go wrong, and that I could enjoy myself on the lighting desk again. Until I remembered that this DJ is not the best, and that I was still hungover. Also, this DJ really really really likes his bass. Several times I had to get him to turn it down cos stuff was vibrating across the table – I thought my netbook would be safe on top of the lighting desk, sitting on some unused (for this party) faders.

I looked away for all of two seconds, heard a crash (over 100dB music, I might add), looked around and saw the external screen for my netbook had lost signal. My phone which was charging from my netbook was missing, as was my netbook.

The whole lot was on the floor.

My phone is fine I think, however the USB cable for it is now almost useless, so I’ve had to buy another one. My netbook also seems fine, though the casing around the screen cracked open. I managed to snap it back together though, but the camera is now in the wrong place inside the casing for it to be any use.

Ah well, guess I’ve learnt to be more careful with my netbook etc.

Unplanned downtime 25/11/2010

Hi folks

This is just a notification of downtime that occurred today.

During a security improvement cleanup sweep of the file tree, a few files required by the system monitor Nagios were accidentally hidden away from it’s view. As such, it started reporting errors on several bits of security software at approximately 03:02. In order to protect the system, these “faulty” bits of software were taken down for immediate repair. However, the procedure to disable the security software also disabled the MySQL database server at approximately 03:10.

The loss of the MySQL server had the following effects:

  • Helpmebot lost connectivity and shut itself down.
  • Exim lost connectivity, and shut itself down.
  • Spamassassin was no longer being depended upon, and so was killed.
  • Due to the lack of Fail2Ban, vsFTPd shut itself down.
  • Due to an unfortunate configuration dependency, Apache was also shut down.

This chain of events effectively killed every service that was running on the server. The offending files were moved to a different location, and the majority of services were recovered by 03:21.

vsFTPd was not restored until after all apparent services had been re-enabled, and Nagios was happy (~ 03:30).

Final cleanup from this incident finished at approximately 04:16.

Apologies for the outage everyone, I’ll try not to do that again. :D