Apple Lion’s new feature “resume” can be nice, but it can be very annoying.

Instead of disabling it for all applications, you can get used to close an application with <cmd>+<alt>+Q. Like this, the application starts clean again after a restart.

Most network devices still got a serial console. If you got a Mac and want to connect to this console, get yourself a Serial-to-USB converter that is supported by Apple. A good one is the Keyspan usa-19hs. After you installed the driver, plug in the USB serial Adapter.

Now you could search and download some Terminal Software. But it is much easier. Use screen. screen is already built in. You have nothing to compile, nothing to add, just use it like this:

screen /dev/tty.Keyserial1 9600

When you finished your work just close screen with “ctrl-a k“.

tcpdump and ngrep are both based on libpcap. Therefore both use the same filter expressions.

Here is the manual page of the pcap filter expression.

Keep one of these keys pressed at system start.

	Eject the inserted CD/DVD
	Boots from a CD/DVD with a system image
	Boots from the first HD partition
	Boots from the network (netboot)
	Enforces a screen reset
	Boots in firewire target mode
	Boots in safe mode. Disables login items and less important kernel files
	Boots in verbose mode
	Boots in single-user mode. Goes directly into command-line

Users coming from the UNIX side are used to a life without anti virus scanner. Microsoft users feel uncomfortable and naked, if they don’t have a virus scanner. This discrepancy always leeds to discussions about the need of an antivirus scanner on an Apple computer. If you ask the AV industrie, they say you need one. Of course, there is a lot of money to make in this market. Experience shows, today you do not really need one.

Currently there are three known trojans for Mac available. One of them only installs, if you get a cracked verison of iWork 09. Even checking the signature list of an antivirus company only gives you a short list. Being a little bit careful from where you download your software helps more then spending a lot of money for software, which just slows down your machine.

Starting with 10.6 Apple started to scan downloads for trojans. There is a file called /System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/XProtect.plist on your Mac containing the signatures of these three known trojans.

Anyway. Currently it is not necessary to spend a lot of money for virus protection on a Mac. If you want to scan your Mac from time to time, get the open source antivirus scanner clamav, with comes nicely packed with a nice frontend in a package called ClamXav. Download the free version and scan your Mac from time to time.