Much simpler method. More portable version: ssh host -l user "`cat cmd.txt`"

this bzips a folder and transfers it over the network to "host" at 777k bit/s. cstream can do a lot more, have a look http://www.cons.org/cracauer/cstream.html#usage for example: echo w00t, i'm 733+ | cstream -b1 -t2 hehe :)

Try to perform a fully TCP 3 way handshake on for a given host-port with a timeout of 1s. Show Sample Output

And then to complete the task: Go to target host; ssh host Turn everything off: for i in `chkconfig --list | fgrep :on | awk '{print $1}'` ; do chkconfig --level 12345 $i off; done Create duplicate config: while read line; do chkconfig --level $line on; done < foo

I'm just a simple programmer. I find dig too verbose. host tells me alias(es) and IP address in a quick to grok format with nothing special to remember for input parameters. With thanks to http://www.cyberciti.biz/faq/how-to-test-or-check-reverse-dns/ Show Sample Output

With no '-q 0' switch, nc simply waits, and whatever awaits the data hangs.

host is a simple utility for performing DNS lookups. It is normally used to convert names to IP addresses and vice versa. When no arguments or options are given, host prints a short summary of its command line arguments and options. Show Sample Output

If the connection works you should see a "hello" on host A. If not: check your cabeling etc :-)

After this, just type: beepwhenup You need to install "beep" before this would make the beep sound. Save it in your .profile if you want to use it later WARNING: this command won't exit until it is successful. You won't be able to CONTROL+C out of it.

This command line detect ldap hosts, by mandatory dns entry, then ping them to detect response average. based on ping response average it sorts and print the faster server in first output line Show Sample Output

Using DynDNS or a similar service not only allows access to your home machine from outside without needing to know what IP the ISP has assigned to it but it also comes in handy if you want to know your external IP address. The only purpose of the sed command is to remove the leading "host.na.me has address " part from the output. If you don't need to discard it you can simply use host $HOSTNAME

command is shorter, output unnecessary longer Show Sample Output

This version uses host and no ruby.

To also move the db backup to another location you could pass the output to the dd command instead of a file mysqldump -u user -h host -ppwd -B dbname | bzip2 -zc9 | dd ssh usr@server "dd of=db_dump"

I must monitorize a couple of ftp servers every morning WITHOUT a port-scanner Instead of ftp'ing on 100 ftp servers manually to test their status I use this loop. It might be adaptable to other services, however it may require a 'logout' string instead of 'quit'. The file ftps.txt contains the full list of ftp servers to monitorize.

Ssh to host1, host2, and host3, executing on each host and saving the output in {host}.log. I don't have the 'parallel' command installed, otherwise it sounds interesting and less cryptic.

parrallel execution of a command on remote host by ssh or rsh or ... very useful for cluster management (software update) Show Sample Output

Show Sample Output

needed; apt-get install tcpkill

Perform a dns zone transfer (if is allowed on target dns server) and print result.

Note, the [remotePort] should be opened in the firewall first. First, start the destination box listening, then fire off the sending box. Data from the /dev/zero device in memory of the source machine is read out using dd, sent over the network with nc, and read back in from the other side of the network with nc, going to the /dev/null device. Essentially, it is a memory-network-memory copy operation, the output of dd will tell you how fast your network really is performing.

DNS cache snooping

traverses e.g. "/data/myhost1.com/myrsyncshare"; logs stderr and stdout. useful with cron.