pcspkr have to be enabled!

modprobe pcspkr

xset b on

If you're very busy and don't want to wait for a ping response, use it.

This command will be waiting for a successful ping response, to play a sound file to warn you that the target host is available.

8.8.8.8 and 8.8.4.4 are two Google public DNS.

As their address is really simple, it's easy to use this command to test if Internet is reachable.

Beware of large corporate networks however, that may use this address on router's loopbacks interfaces.

Does one ping to a URL or host, and echo out just the response time. I use this on, with MRTG to monitor the connections to various hosts.

ignore HUP interruptions

Continue to execute the command in background even though quitting the shell.

Get the IP of a hostname.

This is like ping -a, but it does the opposite. It alerts you if the network is down, not up. Note that the beep will be from the speaker on the server, not from your terminal.

Once a second, this script checks if the Internet is accessible and beeps if it is not. I define the Net as being "UP", if I can ping Google's public DNS server (8.8.8.8), but of course you could pick a different static IP address. I redirect the beep to /dev/console so that I can run this in the background from /etc/rc.local. Of course, doing that requires that the script is run by a UID or GID that has write permissions to /dev/console (usually only root).

Question: I am not sure if the -W1 flag works under BSD. I have only tested this under GNU/Linux using ping from iputils. If anybody knows how portable -W is, please post a comment.

For some reason the 2&>1 does not work for me, but the shorter stdout/stderr redirection >& works perfectly (Ubuntu 10.04).

sending packet by ping

if sending more high packet root needed...

documents all active ips on a subnet and saves to txt file.

# first install arp-scan if not have it

arp-scan 10.1.1.0/24 .... show ip+mac in localnet

awk '/00:1b:11:dc:a9:65/ {print $1}' .... get ip associated with MAC

` backtick make do command substitution passing ip to command ping

This command only check the network connection from given eth. This is very useful if you are using more then one interface in your server or laptop.

Not really an easier solution. But an example using && for (if last command returned 0). You can use || for (if last command returned other than 0)..

Usefull for when you don't have nmap and need to find a missing host.

Pings all addresses from 10.1.1.1 to 10.1.1.254, modify for your subnet.

Timeout set to 1 sec for speed, if running over a slow connection you should raise that to avoid missing replies.

This will clean up the junk, leaving just the IP address:

for i in {1..254}; do ping -c 1 -W 1 10.1.1.$i | grep 'from' | cut -d' ' -f 4 | tr -d ':'; done

A ping flood is a simple DoS attack where the attacker overwhelms the victim with ICMP Echo Request (ping) packets. It only succeeds if the attacker has more bandwidth than the victim (for instance an attacker with a DSL line and the victim on a dial-up modem).

In this command replace 192.168.1.100 with victim IP address.

Alternative to the ping check if your firewall blocks ping. Uses curl to get the landing page silently, or fail with an error code. You can probably do this with wget as well.

Joker wants an email if the Brand X server is down. Set a cron job for every 5 mins with this line and he gets an email when/if a ping takes longer than 3 seconds.

After this, just type:

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.

If you need to ssh into a computer on the local network but you're unsure of the ip to use, then ping them and see if you get a response. If you do, print out the address you got it from. Adjust the range to suit your network.