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Author: halfgaar

http://www.halfgaar.net/

Halfgaar is Wiebe. Wiebe is a contributing author on this weblog. He also has a lot of stuff (such as long, in-depth articles) on his personal website.

Wiebe works at YTEC, where he is a senior developer of customer-specific tailor-made software (“klantspecifieke maatwerk software“) for clients in a few select markets: wholesale, printing and healthcare.

Set proper origin domain for Zimbra server

(This turned out not to be how I fixed it. I just configured exim and /etc/mailname as I do always and that fixed it. However, exim does not run as the SMTP server listening on port 25, that is the postfix installed by Zimbra. I don't know how and if this exim configuration conflicts with zimbra.) Read More »

Changing lost MySQL root password

When you don't know the current mysql root password and you want to change it, do this: /etc/init.d/mysql stop mysqld --skip-grant-tables & mysql -p use mysql; update user set password=PASSWORD("NEW-ROOT-PASSWORD") where User='root'; flush privileges; quit; killall mysqld /etc/init.d/mysql start Read More »

Convenient iptables rules

Here are some convenient iptables rules. This first list is for not allowing anything in, accept packets that come back from outgoing connections, complicated related traffic like FTP, everything from the localhost, ICMP (ping and stuff) and SSH. It also sets the default policy to DROP. This you would use on a machine connected directly to the internet. Read More »

My custom Linux environment

On every machine that I install, I need a custom environment. At the very basic, I need screen and bash customizations. I will attempt to keep this blog post up-to-date with my most recent config. Read More »

Pasting in Vim

When you want to paste in Vim, you want vim to not use indenting, because that messes up your code. I used to use :insert, but on some machines, it would still indent. I discovered the :set paste command, which works quite well.

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UTP wiring

I'm always confused about which wiring scheme to use for UTP cables. After doing some research, it seems T568B is what you need. Wikipedia says that is doesn't really matter, but crosstalk can be a problem for T568A in some esoteric situations: Read More »

Making Coyote Linux work with KPN ADSL

The Dutch ISP KPN gives you a modem+router to access the internet. The router they give you is a custom version of an Alcatel Speedtouch (model varies) and is extremely limited. I don't use any VOIP services, so I replaced that router with a Speedtouch 546 (which supports DHCP spoofing) so that I can use my own Coyote Linux based router. Read More »

Creating a DRBD device

This post is no longer up-to-date. See this one. Read More »

Finding out the UUID of partitions

Often, Linux software configurations define partitions by there UUID as opposed to their /dev device. You can find out what the UUID is with: Read More »

Iptables rule to block access to our IMAP server

When migrating to Zimbra, I don't want people to fiddle with their mail when I'm doing it, so I disable IMAP access from anything but the virtual machine instance in which Zimbra is running. I do that with this: Read More »