Setting up snmpd on ubuntu seems easy, but i never got it full working. It was working locally, but not for a cacti setup from another server. The problem was that the default install of snmpd on Ubuntu starts the demon on the loopback interface only, refusing connections from other computers.

Edit /etc/default/snmpd to fix that:

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# This file controls the activity of snmpd and snmptrapd
 
# MIB directories.  /usr/share/snmp/mibs is the default, but
# including it here avoids some strange problems.
export MIBDIRS=/usr/share/snmp/mibs
 
# snmpd control (yes means start daemon).
SNMPDRUN=yes
 
# snmpd options (use syslog, close stdin/out/err).
#SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -I -smux -p /var/run/snmpd.pid 127.0.0.1'
SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -g snmp -I -smux -p /var/run/snmpd.pid'
 
# snmptrapd control (yes means start daemon).  As of net-snmp version
# 5.0, master agentx support must be enabled in snmpd before snmptrapd
# can be run.  See snmpd.conf(5) for how to do this.
TRAPDRUN=no
 
# snmptrapd options (use syslog).
TRAPDOPTS='-Lsd -p /var/run/snmptrapd.pid'
 
# create symlink on Debian legacy location to official RFC path
SNMPDCOMPAT=yes

that’s it. To restart the snmp server enter $ sudo /etc/init.d/snmpd restart

I’m using iPhone OS 3.x on my iPhone and recently i had problems to get my .mp4 files displayed in mobile Safari. I tried different settings for encoding the files but not a single one worked. When i clicked the link to the .mp4 file in mobile Safari, all i got was the “file can’t get downloaded” error. After some googling i found a clue that it might has something to do with MIME types and the apache server hosting the videos.

Solution:

1. encode your videos for iPhone / iPod Touch (Compressor, Quicktime, Adobe Media Encoder, …)
2. test them on the device (add the video to your iTunes library and upload it to your iPhone and watch it!)
3. upload the video to your webserver
4. make sure you have the following line in your apache config or in a .htaccess file in your directory on your webserver:

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AddType video/mp4 mp4 mp4v mpg4 m4v

That’s it, now progressively watching .mp4 videos from your webserver on your iPhone should work (again).

I had the need to move my blog running wordpress 2.0.x to a different server, but keeping the domain name on the “old” server. I used mod_rewrite and with a lot of trial and error and some updates i finally got this working solution:
Read more…

I upgraded one server to new hardware by changing the complete HP machine, but using my harddrive from the “old” server. As these two machines are almost identically, except for the processor (dual core now) this should have worked like a charm – and it did! (almost)

I rebooted on the new hardware, all services and serves came up, no problems so far. But when i tried to ping some other machine, this didn’t work

I checked /var/log/messages and the onboard Broadcom Interface showed up as eth1, but i was not able to start it. When i ran $ sudo /etc/init.d/networking restart i got some error messages like:

SIOCSIFADDR: No such device eth1
eth1: ERROR while getting interface flags: No such device

No clue what went wrong, i googled a lot and finally i stumbled upon this forum entry: http://ubuntuforums.org/showthread.php?t=221768

Then i ran: $ ifconfig -a
and got a list with my network interfaces and more importantly with it’s MAC address.

Then i edited /etc/iftab and changed the MAC address of the old hardware to the new onboard interface’s MAC address.

restart the networking with $ sudo /etc/init.d/networking restart

YESS, it works!

i just found out that my Ubuntu Server 6.10 has login shells for almost all users set in the /etc/passwd file!

That’s a very bad idea because this maybe enabled someone to install “Data Cha0s Back Backdoor” on my machine

I checked this with 2 other fresh Ubuntu Server 6.10 installations and both had the login shells for users like daemon, mail, www-data and so on. Especially www-data should not have a chance to create a shell in my opinion!

So i changed /bin/sh to /usr/sbin/nologin and hope this makes it a bit more secure.