Checking internet connection without a winbox

Les Mikesell lesmikesell at gmail.com
Sun Jul 2 18:12:45 UTC 2006


On Sun, 2006-07-02 at 12:17, Dotan Cohen wrote:
> On 02/07/06, Les Mikesell <lesmikesell at gmail.com> wrote:
> > Run traceroute to various places and note where the delays or
> > dropped packets start.  Normally you will see a response from
> > every router in the path and the round trip time for three
> > packets.  Some may block the ports used or the icmp response
> > so a '*' response isn't necessarily a problem, especially
> > if it picks up on subsequent hops.  Keep in mind that the
> > time is for the round trip and problems can happen in either
> > direction.  If you see consistent delays or drops happening
> > somewhere, paste the traceroute into an email to your ISP.
> >
> 
> Thanks, Les. I started doing mtr, and discovered that the router is
> dropping ~2% of the packets, the infrastructure is dropping ~14% of
> the packets, and the ISP is dropping ~8% of the packets. all the other
> hops are losing between 2% to 10% as well. What values are considered
> normal? Thanks.

I'd consider 'none' to be normal.  But keep in mind that you are
always testing the whole round trip even though it is only
reported as the path to something.  If something nearby is
dropping packets it is probably also responsible for the
ones reported on the path to more distant things.  Clean up
the problem with your router before looking anywhere else.
If you are dropping packets on your ethernet connection to
your own router, you almost certainly have a duplex mismatch
on the switch connection to the router or pc.  If it is on
the T1 side, it is probably overloaded. Look for compromised
machines spreading viruses/spam or file sharing.  Do you
have access to the router to see the interface statistics
for traffic and errors?

-- 
  Les Mikesell
   lesmikesell at gmail.com
  




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