At my job we use more excel spread sheets than I care to comment on. I have always used excel for various tasks but lately I have needed to learn it more. One thing I found really anoting is that you cannot open multiple windows with excel spread sheets. This makes transfering and comparing data in between the tough. So thanks to some vetern guys at my work, they showed me a little registry hack to get this working.
I recently aquired a new GPS device for use with programs like Kismet and Airodump-ng. Its been a while since I have used GPS devices in Linux and back then they were serial devices. The BU-353 dvice is a USB device so I had to figure out how to get it going.
If you are a system administrator you probably manage one or more email servers so things eventually will go wrong and need to be resolved as quickly as possible. It is beneficial to know how to troubleshoot email servers using telnet via a shell so you don’t have to rely on a GUI mail client. Below I describe how to login to an Exim email server using telnet, authenticate via SMTP authentication, and then send test emails. The below examples will be run from a terminal window on Linux however they should be very similar too running the commands from a Command Prompt on Windows 7 or any other operating systems using a terminal window or similar.
I have been needing to upgrade the PostgreSQL servers at my work for awhile now and was finally forced to do so after needing some of the features available with PostgreSQL 8.4.X. Currently we are running PostgreSQL 8.3.10 which is super old but it is definitely not the latest stable release available. One thing I am looking forward to testing is the improvements to the vacuum process. Over the past two years I have become a lot more familiar with Postgres and one thing that has been disappointing is the downtime involved in reclaiming disk space via data removed from PSQL database tables. The full vacuum process, which is required to reclaim disk after deleting data from a table, in 8.3 requires a lock on tables which essentially causes downtime. When you are dealing with large tables over 10GB in size this can take days to complete. Follow the directions below to first backup all of your PostgreSQL data, remove the current PostgreSQL installation, and then install PostgreSQL 8.4 on a CentOS Linux server.
A while ago I wrote a short tutorial on how to strip down a wireless capture which contained a wpa handshake so that only eapol packets and beacon frames where left. I have since found a little bit better way to do it so I decided to make a new post. In the previous article I showed how to strip by wlan.mgt frames containing the mac address. The problem with this is that it strips out lots of other packets which some programs use to check for ESSID. I looked into the issue some more and found a way to strip just by essid.