Problem: You want to know which switch and what port your Linux machine is connected to? Solution: If the switch does CDP (all Cisco switches do), it tells you a lot of information. Tcpdump can capture and show this information. # tcpdump -i eth0 -n -v -s 1500 -c 1 ‘ether[20:2] == 8192’ tcpdump: listening […]
Problem: After updating from debian lenny (5) to squeeze (6) ejabberd authentication (PAM) stopped working. Solution: ejabberd uses an external programm called epam to authenticate. But this programm had no permission to use pam. I had to type these commands: chown root.ejabberd /usr/lib/ejabberd/priv/bin/epam chmod 4750 /usr/lib/ejabberd/priv/bin/epam killall epam ejabberd 2.1.5-3+squeeze1
ejabberd on debian with pam Read More »
When you have a mysql table with lot’s of attributes, it’s hard to read the output of a statement like this in mysql: select * from table limit 1; The data is folded very ugly. Easy Solution: select * from table limit 1 \G Mysql is showing one “Fieldname: Value” per line.
Mysql “Select” Output Turned Arround Read More »
Problem: If you want to add water marks onto a pdf document, you have to merge two pdf files into one pdf file. Solution: On Linux there is a tool called pdftk (PDF Toolkit), which can do this. pdftk <letter.pdf> background <background.pdf> output <letter-with-background.pdf>
Howto: Merge two PDF Files onto One Page Read More »
I don’t burn CDs often, but when I do I still look for “cdrecord”, which doesn’t exist on debian anymore. Debian forked the source and renamed it to wodim, because of a license dispute between the Debian maintainers and cdrtools author Jörg Schilling.
cdrecord is called wodim now Read More »
If you like to restrict access to a directory on your Apache web server to users from a fixed IP range without password, and the rest of the world with password authentication the httpd.conf section can look like this for Apache-2.2: For apache-2.4 the syntax has changed to:
Apache Authentication by IP and Password at the Same Time Read More »
Challenge: You have a linux based firewall, which should forward all internal and external traffic of its connected clients through a VPN tunnel, and at the same time the traffic from the firewall itself should not go through the tunnel (e.g. the tunnel connection packets). Solution: There are lots of howtos for this probably. Here
Multiple Routing Tables with IPTables Read More »
I just read that MircoSoft announced a “new” software to control two WindowsPCs with one keyboard and mouse. It might be new to MircoSoft but a software for this exists since about 1998. When I had both Linux and Windows on my desktop some years ago I used x2vnc for this. Read on: http://fredrik.hubbe.net/x2vnc.html
One Mouse and Keyboard for Two Computers Read More »
I don’t use Gnome, KDE, etc. My window manager is WMX with some patches. Without all those fancy window environments, you get rid of all magic auto configurations, and wizards at the same time, and you can configure your system like real man do: using the command line. ;-) I bought a HP OfficeJet Pro
Using an HP scanner on the command line Read More »
If you look into a harddisk from an HP server with smart array configured for raid1, you will recognize that the partition table of this disk has only one partition: Device Boot Start End Blocks Id System <device>p3 1 1 8001 12 Compaq diagnostics The real partitions are invisible? No. I found the start of
Restore data from a single disk of an HP/Compaq SmartArray raid1 Read More »