Sunday, April 2, 2006

Networking Basics - Ping

Ping is an ICMP (Internet Control Message Protocol) ECHO request over TCP/IP used to test connectivity.
It's use isnt always reliable as firewalls tend to be configured to block them on external networks.

PING [hostname/ip] By default sends 4 (64k) packets of data.

PING /? To see options

Most useful >

PING {hostname/ip] -t Repeatedly pings until stopped (useful for monitoring reboots)

PING {hostname/ip] -r n Displays information on route taken. (n = 1-9)

Ping showing route taken to local server >

C:\>ping -r 5 webserver01

Pinging webserver01.domain.co.uk [172.29.0.86] with 32 bytes of data:

Reply from 172.29.0.86: bytes=32 time=9ms TTL=124
Route: 10.0.1.50 ->
10.192.0.6 ->
172.16.253.251 ->
172.16.254.252 ->
172.29.0.86
Reply from 172.29.0.86: bytes=32 time=7ms TTL=124
Route: 10.0.1.54 ->
10.192.0.2 ->
172.16.253.251 ->
172.16.254.252 ->
172.29.0.86
Reply from 172.29.0.86: bytes=32 time=10ms TTL=124
Route: 10.0.1.50 ->
10.192.0.6 ->
172.16.253.251 ->
172.16.254.252 ->
172.29.0.86
Reply from 172.29.0.86: bytes=32 time=9ms TTL=124
Route: 10.0.1.54 ->
10.192.0.2 ->
172.16.253.251 ->
172.16.254.252 ->
172.29.0.86

Ping statistics for 172.29.0.86:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 7ms, Maximum = 10ms, Average = 8ms


Ping -r doesnt show route to an external site, just returns standard ping results >

C:\>ping -r 5 google.co.uk

Pinging google.co.uk [72.14.221.104] with 32 bytes of data:

Reply from 72.14.221.104: bytes=32 time=54ms TTL=243
Reply from 72.14.221.104: bytes=32 time=26ms TTL=243
Reply from 72.14.221.104: bytes=32 time=26ms TTL=243
Reply from 72.14.221.104: bytes=32 time=79ms TTL=243

Ping statistics for 72.14.221.104:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 26ms, Maximum = 79ms, Average = 46ms


Equivalent and improved functionality is provided by TRACERT and PATHPING

No comments: