But  the  only  item of interest for "how the WAN link is performing" is
the hop from your router to your ISPs.  Ping/traceroute can only measure
one protocol at a time.  Its also subject to any rate limiting and other
QoS limitations in effect at your or your ISPs router.

All true, but if a link is congested and/or dropping packets and sessions in application or whatver protocols, then mtr's icmp stuff will also be screwed up. I'm not proposing mtr as a protocol sniffer/analyzer, but only as quick and easy go/no-go evaulator.


> Sure, but not everybody who runs Imail has admin access to the local router
> or Cisco command skills.

True  but  everybody should be able to look at an MRTG graph and see the
pretty coloured lines go up and down.

suits and big picture artists like them pictures as "management appreciation". :)


mtr has  -report mode, eg, run for 1 minute, and print  the summary >> file.

repeat that every 10 minutes, and you have a long-term data record.

But  it  doesn't  give  many  hints as to why the WAN link is performing
badly.

see above.

The first question is GO/NO-GO?? is the link fast, stable, not dropping packets OR NOT.

If yes, go look elsewhere.

If no, then you can start playing with more detailed tools (if you have them).

I  was  just  objecting to your "exactly how the WAN link is performing"
phrase.

1000 ms avg ping times to the adjacent hops, and 5% packet less tells me the WAN link is a nightamre.


3 ms ping times and 0% packet lost in 24 hours tells men the WAN link is cool.

Having  MRTG in place also gives history so when someone says "I came in
on  Saturday  and response time was terrible" you can see if there was a
utilization spike at some point.

long term data is of course useful for long term decisions. Most sys admins work in short-term.


Glancing  at  the  graphs  can  also  give  an  indication of increasing
bandwidth needs so you've got time to start budgeting for an upgrade.

increasing data volumes means increasing slowest-line congestion, and the above capture file is all you need to see that.


"simpler is always better", and mtr is vastly simpler to install and run than MTRG. I have yet to install MRTG anywhere in 100s of IMGate installs as a sys admin tool, and I've identified, and often fixed, problems with boxes I'm NOT hired to fix (routers, wan links, next hop screw ups, etc, etc), using simple stuff like mtr and postfix logging.

Len

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