Tag linux

May 24, 2014

Capturing whole packet with tcpdump for analysis with wireshark

Capturing the hole packet on your NIC for later analysis with wireshark $tcpdump -nnvvXSs 1514 -i em0 -w /tmp/em0.dumptcp Will capture 1514 bytes of all packets on interface “em0” and dump it to the file “/tmp/em0.dumptcp”. You can then import the file into wireshark for analysis. Explanation of Parameters Text below is copied from tcpdump man page -nn Don’t convert protocol and port numbers etc. to names either. -vv Even more verbose output.

July 24, 2011

Howto: apt-cacher with ubuntu

If you have an office with loads of linux computers, it might be useful to have a local repository to save bandwidth on you local wan. But a local repository needs to be up-to-date and it’s hard to decide which packages should be mirrored. If you want to have a good and useful mirror you’ll probably waste a lot of hard drive space and also a lot of your wan bandwidth updating never used packages.

March 3, 2011

Which Ubuntu version is installed?

If you are just interessted in the Ubuntu version then type lsb_release -a gives you an output like this: No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 10.04.2 LTS Release: 10.04 Codename: lucid If you like to now the kernel version then type uname -a Linux myhostname 2.6.32-29-generic #58-Ubuntu \ SMP Fri Feb 11 19:00:09 UTC 2011 i686 GNU/Linux

February 23, 2011

screen as a minicom alternative?

for those who still use minicom to connect to a console (serial) port on a cisco (or whatever) device: i prefer “screen”, because its so easy, and for the most things it’s all you need. screen should be already pre installed with ubuntu, with osx it’s easy to install using macports. to use it, just type: screen /dev/ttyS0 9600 Where ttyS0 is your serial device and 9600 the baudrate to close the session you have to press ctrl-a k and then y (for yes)