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Network Configuration—Basics64 bytes from 192.168.0.20: icmp_seq=1 ttl=64 time=0.990 ms64 bytes from 192.168.0.20: icmp_seq=2 ttl=64 time=0.972 ms--- 192.168.0.20 ping statistics ---3 packets transmitted, 3 packets received, 0.0% packet lossround-trip min/avg/max/stddev = 0.794/0.919/0.990/0.088 msIn the above example, the ping utility is used to transmit 3 ICMP packets (note -c3option) to host the IP address 192.168.0.20. If the packet count is not specified,ping will continue to transmit ICMP packets until it receives a TERM signal (orsimply the CONTROL-C key combination on the console).Once it finishes, ping prints two lines of statistics including the number of packetstransmitted, the number of packets received, which should normally be equal to thenumber of packets that were sent and the percentage of lost packets. In the secondline, the packet round-trip time is minimum, average, and maximum. Finally thestandard deviation is printed.The default ICMP packet size that ping transmits is 56 bytes data (which will become64 bytes when lower layer headers are inserted).Using these statistics, you can simply find out the connectivity quality to thedestination host from delay, packet loss, and the jitter point of view.Despite the simplicity, ping has several options that can be combined toget different types of results. It is recommended that you see the ping(8)manual page for more detailed information.TracerouteWhile the ping(8) utility can be used for end-to-end connectivity test, thetraceroute(8) is used to find out the route between source host and destinationhost and discover all the layer3 hosts between two nodes.The traceroute utility uses the TTL feature to discover routers between two nodes.It transmits packets (UDP or ICMP) towards destination host with a TTL of 1. Oncethe first router in path receives the packet, it decrements the TTL and returns anICMP TIME_EXCEEDED message back to the source host. The traceroute commandsends as many packets as it discovers, to all interim hosts and reaches thedestination host.# traceroute freebsd.orgtraceroute to freebsd.org (69.147.83.40), 64 hops max, 40 byte packets1 208.79.80.97 (208.79.80.97) 1.831 ms 1.976 ms 2.000 ms[ 122 ]