When I upgraded to OS X 10.7 (Lion), I started using the built-in IPSec VPN client rather than Cisco's VPNClient. I experienced problems immediately. At first it appeared that the connection was being made, but no traffic was passing. When I tried pinging by IP address, I found that traffic was passing, but I couldn't do anything by hostname.

Categories: System Administration

If you're a frequent user of GNU screen on your Mac, you are probably tired of using ctrl-a [ to enter scrollback mode. Adding the following lines to the .screenrc configuration file in your home directory in order to scroll with your mouse: defscrollback 5000 termcapinfo xterm* ti@:te@

Categories: System Administration

I've dealt with a few servers that have long lived popper (POP3) processes. These processes should be closed once the connection is closed, but they occasionally hang around. Once they get in this state, they will never close on their own. After a while, hundreds of these processes will just be consuming resources. Below is a command line that I run from a BASH shell to kill off these old processes. It's designed to kill any popper process that has been around for 10 days or longer.

Categories: System Administration

One of the beauties of using a Linux-based Mail Transport Agent (MTA) like Sendmail is the ability to pipe mail into programs. You can use this in conjunction with a filtering application like procmail, with a custom application that collects data about the email, or anything else you can imagine. Occasionally that ability fails.

Categories: System Administration

Why is it always a pain to find this stuff in the documentation?

Categories: System Administration