Nortel Networks 1005r User Manual

Page of 206
June 2007
Using Windows online diagnostic tools
1005r Server Maintenance and Diagnostics
51
To run the ping command from Windows
1
Click Start > Programs > Accessories > Command Prompt
Result: The Command Prompt dialog box appears.
2
Type ping <destination IP address> (for example, ping 
200.286.32.0) or ping <computer name>.
3
Press Enter.
Result: The system displays the ping results.
4
Type Exit to exit the Command Prompt dialog box and return to 
Windows.
The tracert command
This utility determines the route taken to a destination.
How tracert works
The tracert utility follows several steps to complete its task:
„
Tracert sends Internet Control Message Protocol (ICMP) echo 
packets with varying Time-To-Live (TTL) values to the destination.
„
Each router along the path must decrement the TTL on a packet by 
at least 1 before forwarding it, so the TTL is effectively a hop count. 
„
When the TTL on a packet reaches 0, the router sends back an 
ICMP Time Exceeded message to the source system.
„
Tracert determines the route by sending the first echo packet with a 
TTL of 1, and incrementing the TTL by 1 each subsequent 
transmission until the target responds or the maximum TTL is 
reached. 
„
Tracert then examines the ICMP Time Exceeded messages sent 
back by intermediate routers.