The ping command is one of the popular command used in linux for troubleshooting, testing and diagnosing network connectivity issues.
The ping command sends a request to destination ip or domain name and wait for the reply if request is received by other party it will respond back with ICMP (Internet Control Message Protocol) echo reply.
The ping command will continue to send ICMP packages to the Destination IP address until it receives an interrupt. To stop the command, just hit the Ctrl+C key combination.
Syntax
ping [OPTIONS] [IP or Domain]
Let's have a look at the example:
# ping google.com ping google.com # output of above command PING google.com (172.217.164.238): 56 data bytes 64 bytes from 172.217.164.238: icmp_seq=0 ttl=54 time=5.985 ms 64 bytes from 172.217.164.238: icmp_seq=1 ttl=54 time=5.860 ms 64 bytes from 172.217.164.238: icmp_seq=2 ttl=54 time=6.551 ms ^C --- google.com ping statistics --- 3 packets transmitted, 3 packets received, 0.0% packet loss round-trip min/avg/max/stddev = 5.860/6.132/6.551/0.301 ms
The ping command resolves the domain name into an IP address and starts sending ICMP packages to the destination IP.
If the destination IP is reachable it will respond back and the ping command prints a line that includes the following fields:
# sample output 64 bytes from 172.217.164.238: icmp_seq=0 ttl=54 time=5.985 ms # explanation number of bytes: 64 ICMP data bytes IP address: from 172.217.164.238: The ICMP sequence number for each packet: icmp_seq=0 The Time to Live: ttl=54 The ping time: time=5.985 ms
Send N packets and stop
To limit number of packets using ping command use following command:
# command syntax ping -c [packets] destination # example ping -c 1 google.com # sample output of above command PING google.com (172.217.164.206): 56 data bytes 64 bytes from 172.217.164.206: icmp_seq=0 ttl=54 time=4.422 ms --- google.com ping statistics --- 1 packets transmitted, 1 packets received, 0.0% packet loss round-trip min/avg/max/stddev = 4.422/4.422/4.422/0.000 ms
Increase Ping Time Interval
Example: Wait for 5 seconds before sending the next packet.
# increase the interval time ping -i 5 google.com # decrease default interval time ping -i 0.1 google.com
Check whether the local network interface is up and running
# ping without name ping 0 # example using name ping localhost # ping using ip ping 127.0.0.1
Flood the network
Super users can send hundred or more packets per second using -f option.
sudo ping -f localhost
Give beep when the peer is reachable
Using -a option it can beep when target is reachable:
ping -a google.com
Print Only Ping Command Summary Statistics
Use option -q to view only the ping statistics summary as shown below:
# example command ping -c 5 -q 127.0.0.1 # example output PING 127.0.0.1 (127.0.0.1): 56 data bytes --- 127.0.0.1 ping statistics --- 5 packets transmitted, 5 packets received, 0.0% packet loss round-trip min/avg/max/stddev = 0.045/0.076/0.120/0.027 ms
Change Ping Packet Size
To change the default packet size from 56 to N use -s option as below:
# example command ping -s 100 localhost # example output of above command PING localhost (127.0.0.1): 100 data bytes 108 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.044 ms ^C --- localhost ping statistics --- 1 packets transmitted, 1 packets received, 0.0% packet loss round-trip min/avg/max/stddev = 0.044/0.044/0.044/0.000 ms
In above example event though we specified 100 bytes it displays 108 bytes this is because it adds the header byte size along with the packet size specified.