tar oneliner: backup to a network location

tar is a pretty straightforward and handy tool that anyone administering anything on a *nix box should learn. If I don't have a typo, the below one liner will create a system backup, excluding the named directories and send it via SSH to a remote server, where the .tar file will be written. Errors are redirected ( 2> ) to a log file in /var/log/backups (assuming you have this directory and it has the appropriate permissions.
One last note: if you don't run this as root, you won't get a complete (if any) archive created.

Command (the line break is only formatting on here. This command can be entered on one line.
tar cvpj --exclude=/dev/* --exclude=/sys/* --exclude=/tmp/* / 2> /var/log/backups/`date +%d%M%Y`_Backup.log | ssh yourserver "cat > /home/backups/`date +%d%M%Y`_Backup.tar"

c - create backup tar
v - list files being tarred
p - maintain file perms
j - use bzip2 (slower but deeper compression) / can use z instead which is gzip
g - could be added to this string of commands in order to create incremental backups
--exclude=   exclude some directory. The trailing * will stop tar from creating an empty copy of the excluded directory.
ssh - should be self-explanatory

To schedule this, you can use at or create a new cron entry such as:
10 * * * 1,3,5 /usr/bin/backup
were /usr/bin/backup is a script containing the above tar command and the command should run at 12:10 am on Monday, Wednesday, and Friday (days 1, 3, and 5 of the week)

ngrep oneliner: look for a domain name in DNS traffic

ngrep is a pretty useful tool and should be useful to any network security work. It is NOT the same as tcpdump, in case anyone was wondering. I may be a little off in my explanation tonight, but ngrep does something so much better than tcpdump: searches for regex's.

So, to search for a hostname, as a whole word, in DNS traffic in an already captured traffic file:

ngrep -w 'somehost' -I /stored/mypcaps.pcap port 53

mtr oneliner: better than tracert sometimes

Another really quick on since I have two research papers to start .
A good tool for testing network link(s) is mtr. Check out the man page on your favorite linux machine or on the net.

mtr google.com

or, to use only IPv4 and skip DNS resolution on each hop:
mtr 4 --no-dns google.com

or, if you want to do the same thing but see how fast you can get into trouble at work or home:
mtr 4 --no-dns playboy.com

netstat oneliner: what process are associated with what ports

Ever wanted to know what ports are open and what process is using these ports? Run the below as root and you should have your answer.

netstat -tlnp