Just what in the world does icmpeko stand for, anyway? OK, so it’s spelled a bit differently than it should be. I couldn’t fit the whole thing in the seven characters allowable on my California vanity plates. I think it’s close enough, though – I’ve actually had people come up to me and correctly ask if it meant, “ICMP Echo,” so it’s close enough in my book. I guess you need to be part of a select group of geeky computer people to get it… Keep reading to find out more about the how this protocol is used in an Internet PING, the bread & butter of my profession.
ICMP ECHO
ICMP Echo, or [Internet] PING, is the basis for almost all network management utilities and tools and is the tool most responsible for paying my bills. So, what’s a PING, you ask?
Ping
Mariners use a different kind of PING to verify their range to a particular target. They send a sound (or SONAR) signal toward their target and measure the time it takes for the return signal, or echo. An Internet PING works much in the same way.
The Packet INternet Groper is a program useful in testing and debugging LAN/WAN troubles. It sends out an Internet control message protocol (ICMP) echo and expects a specified host to respond back in a specified time frame (the echo reply).
More Info (getting hairy)
The ping command works much like a submarine sonar ping. The source host sends a packet called an ‘ICMP Echo Request’. When that signal reaches its destination an ‘ICMP Echo Reply’ is sent back to the source of the signal. This verifies that packets can get to a host and back again. Internet Control Message Protocol (ICMP) is the transport protocol used by ping (see RFC 792). See link: http://www.ietf.org/rfc/rfc0792.txt for the gorey details.
If the host does not receive an ‘ICMP Echo Reply’ to its ‘ICMP Echo Request’ then the host will continue to send ‘ICMP Echo Request’s once a second until an ‘Echo Reply’ has been received or until 10 ‘Echo Requests’ have been sent.
The ping command can also be used to test Domain Name Service (DNS) or be used to resolve a host name. If the ping command is given a host name for an argument instead of an IP address the host will attempt to resolve the host name by sending a DNS query to whatever DNS server is specified in the global settings. The resolution of that host name to an IP is shown.
Command Syntax
In Windows, you need to first open an MS DOS Prompt and type the items below in bold:Command >ping [ip address, hostname] ping # terminates ping
NOTE: Ping with no arguments will terminate a ping.
Example
You can PING a host by its IP (Internet Protocol) address:C:\>ping 67.119.46.82Pinging 67.119.46.82 with 32 bytes of data:Reply from 67.119.46.82: bytes=32 time<10ms TTL=150 Reply from 67.119.46.82: bytes=32 time<10ms TTL=150 Reply from 67.119.46.82: bytes=32 time<10ms TTL=150 Reply from 67.119.46.82: bytes=32 time<10ms TTL=150
Ping statistics for 67.119.46.82: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 0ms, Maximum = 0ms, Average = 0ms
You can also PING a host by its hostname: C:\>ping stanislawczyk.com
Pinging stanislawczyk.com [67.119.46.82] with 32 bytes of data:Reply from 67.119.46.82: bytes=32 time<10ms TTL=150 Reply from 67.119.46.82: bytes=32 time<10ms TTL=150 Reply from 67.119.46.82: bytes=32 time<10ms TTL=150 Reply from 67.119.46.82: bytes=32 time<10ms TTL=150Ping statistics for 67.119.46.82: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 0ms, Maximum = 0ms, Average = 0ms