Traceroute:
Traceroute is a
network diagnostic tool that is used to trace the path that an Internet
Protocol (IP) packet takes from a source device to a destination device.
It is commonly
used to identify network connectivity issues, and to determine the specific
network devices that are causing problems.
To Run Traceroute, Follow the Steps Below:
Windows (XP,
2000, 98, or ME)
Click Start and
then click Run.
Type cmd and then click OK.
Type tracert, the IP address or website name and then click Enter.
Mac OS 10.x
Go to the Finder
and choose Applications.
Select the
Network Utility from the Utilities folder.
Choose
the traceroute tab.
Enter an IP
address or website name and start the trace
Here’s a breakdown of
the key components of the output:
Hop number: This is the
number of the hop in the path from the source host to the destination host.
Each hop represents a router or network device that the packets pass through.
IP address: This is the
IP address of the router or network device for the current hop. The IP address
is used to identify the specific device that the packets are passing through.
Host name: If
available, this is the DNS hostname of the router or network device for the
current hop. Some routers may not have a hostname associated with their IP
address, in which case the field will display an asterisk (*).
Round-trip time (RTT):
This is the time it takes for a packet to travel from the source host to the
current router or network device, and back to the source host. The RTT is
measured in milliseconds (ms) and can be used to identify any delays or other
issues along the path.
When we send a
ping from source to destination and this ping doesn’t work, what does it mean?
We’ll know something is not working but we don’t know which hop/router in
between source and destination causing issue.
The traceroute
command will help us with that. Here’s a quick example:
As you can see we
are getting all the router with hostname and ip addresses in between source and
destination. that we don’t get using ping.
By
default, tracert sends three packets to each hop, so the output lists
three roundtrip times per hop.
Called RTT (Round
Trip Time).
If an asterisk
(*) appears for RTT, then a packet was not returned within the expected
timeframe.
One or two
asterisks for a hop do not necessarily indicate packet loss at the final
destination.
Many Internet
routers intentionally discard ping or traceroute packets, but this has no
bearing on applications that use these routers.
This practice is
called ICMP Rate Limiting and is used to prevent routers from being impacted by
denial-of-service attacks.
Three asterisks
followed by the “Request timed out” message may appear for several
reasons. See the “Request timed out” Message sections that follow.
Note:
RTT
values of less than 150 ms from your home to the final destination shouldn’t
impact internet applications. Many applications work just fine with
latencies even higher than that, but for sites that are US-based they should
fall below 150 ms and usually are < 100 ms.
If
the source and destination are thousands of miles apart, average latency values
of 100-120 ms are acceptable as
communication is limited by the speed of light over the entire physical fiber
distance.