System Administration Guide: IP Services

How to Determine if a Host Is Losing Packets

If you suspect that a machine might be losing packets even though the machine is running, you can use the s option of ping to try to detect the problem.

    On the command line, type the following command.

    % ping -s hostname

ping continually sends packets to hostname until you send an interrupt character or a timeout occurs. The responses on your screen resemble the following:

PING elvis: 56 data bytes
64 bytes from icmp_seq=0. time=80. ms
64 bytes from icmp_seq=1. time=0. ms
64 bytes from icmp_seq=2. time=0. ms
64 bytes from icmp_seq=3. time=0. ms
----elvis PING Statistics----
4 packets transmitted, 4 packets received, 0% packet loss
round-trip (ms) min/avg/max = 0/20/80   

The packet-loss statistic indicates whether the host has dropped packets.

If ping fails, check the status of the network that is reported by ifconfig and netstat, as described in ifconfig Command and netstat Command.