Upstream Provider Woes? Point the Ping of Blame - page 3
Network Admin's Best Tool
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$ mtr mail.bratgrrl.com
This shows that the
entire path from my PC to my mail server is a congested mess. Of
particular interest are the first and last hops: router.ortelco.net shows 21% packet loss, and my mail server, venus.euao.com,
shows a 36% packet loss. Should I send a LART to my service providers?
Not quite yet. The next step is to run the same test at different times
of day over the next couple of days. To generate nicely-formatted,
copy-able output, add the
-r flag, and limit the number of packets sent with the
-c flag. Then store the output in a file:
$ mtr -r -c100 yahoo.com >> test.txt
Slap it into a cron
job, running it every hour or so, and in a day or two you have a good
snapshot of what is happening on a particular link. Suppose that this
shows venus.euao.com is consistently dropping bales of packets; what comes next? Create a trouble ticket using the output of
mtr to show the service provider that the problem is specific to their server, and not somewhere else downstream.
What if your external
testing demonstrates no particular problems? Then you know you need to
investigate your LAN for the source of your network troubles.
mtr works on the inside just as well as the outside.