Tag: Linux
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Disable SSLv3 in Postfix, Dovecot
Postfix: Disabling certain versions of SSL works like this in Postfix: In your /etc/postfix/main.cf add or modify the following config parameter like so: smtpd_tls_protocols=!SSLv2,!SSLv3 If you are using mandatory TLS you’ll want to set this instead: smtpd_tls_mandatory_protocols=!SSLv2,!SSLv3 These should be fairly self-explanatory, but for further detail read the Postfix configuration parameters documentation. Do not forget […]
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scrub: -X argument cannot exist
I’ve been looking for a utility that will clean disks for me – and I do realize this is no real substitute for shredding them. Anyway, scrub seems to do the job. However, when I tried to run it I got: scrub: -X argument cannot exist This had me stumped because I read it as […]
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Could not perform immediate configuration on ‘python-minimal’
When I tried to update my Debian box, I got the following ominous error: E: Could not perform immediate configuration on ‘python-minimal’.Please see man 5 apt.conf under APT::Immediate-Configure for details. (2) It turns out that the fix is fairly simple. The following worked for me: apt-get install -o APT::Immediate-Configure=false -f apt python-minimal
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How to Set Up a TFTP Server
Analog devices has a great and quite thorough “How To” on Setting Up a TFTP Server.
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NFS: “bad superblock”
If you’re getting a “bad superblock” error message when attempting to mount an NFS volume, make sure that you have portmapper installed and running.
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Postfix error – fatal: parameter “smtpd_recipient_restrictions”
I encountered this error when I added a check_sender_access clause to my smtpd_recipient_restrictions in postfixes “main.cf”: fatal: parameter “smtpd_recipient_restrictions”: specify at least one working instance of: check_relay_domains, reject_unauth_destination, reject, defer or defer_if_permit. I haven’t really checked, but I am guessing this is because smtpd_recipient_restrictions as the last clause isn’t specifically rejecting all mails that aren’t […]
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Setting Sender Address in Mutt
I’m a Pine user. I seriously dislike mutt. It’s terribly uncomfortable to use. But it is maintained, and luckily it’s quite flexible and can be changed in how it acts. I’m trying to get by with mutt… and it’s a slow process, one step at a time. First annoyance, by default it uses my machine […]
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Turning off Syntax Highlighting in vim
Today my screen is a bit dark – or rather, the office is bright, what with all the sun outside. This makes some of the colors of vim’s syntax highlighting hard to read. How do you turn this on or off? After you open a file, and press ESC. With: :syntax off you can turn […]
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Enabling SSL in Apache2 on Ubuntu
I’m using my server for various admin interfaces and so want to SSL encrypt all traffic to the web server. This is easy enough to add to the default vhosts. First, we need an SSL certificate. Create it by running: openssl req -new -x509 -days 3650 -nodes -out /etc/ssl/certs/apacheserver.pem -keyout /etc/ssl/private/apacheserver.pem This generates a self-signed […]
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Moving eJabberd
If you need to migrate ejabberd, you need to be aware that -at least on Debian/Ubuntu- it uses your machine name as the default nodename, or to be more precise, ejabberd@hostname. This can be controlled in /etc/default/ejabberd but unless you already knew about it, it’s a done deal already. So, my naive approach of just […]