Initial Route Server Stats for MAE-East
Jeff Young
young at mci.net
Mon Oct 23 01:04:19 UTC 1995
by all means, ping all you like. please do realize that
routers have other things to do besides answer pings when
they're busy. just because a router doesn't respond to
15% of its pings doesn't mean that it's dropping 15% of
its packets or that there is a 15% loss on a line. router
load is not router load, process switched packets are not
the same as card-level switched or cache switched.
there aren't any easy answers. perhaps we should all just
implement "ping" servers in pops ( a 386 running
linux or bsd might suffice).
Jeff Young
young at mci.net
>
> >
> > On Sat, 21 Oct 1995, Mike O'Dell wrote:
> >
> > > remember that using pings to sample connectivity to a very busy
> > > cisco router is not a very reliable probe for several reasons.
> > > Returning pings is a low-priority task in the first place, and
> > > they are rate-limited, so if the processor is busy processing
> > > lots of BGP updates and several folks are fribbling with it
> > > using ping or SNMP, it is less than clear what they will see.
> > >
> > > -mo
> >
>
> Michael A. Nasto quips:
>
> > OK! Agreed. So then, what would you use?
> >
>
> Have you ever been in a classroom and had a student raise his hand,
> answer every question, ask intelligent questions, etc. just to prove
> to the class how smart he or she is. This is the premise of
> the 'Two Mike's Interchange' above. One says, HEY! I know ping packets
> are a lower priority than everything else in a *CISCO* router
> LOOK AT ME (wave wave). Then another kid in the class quips...
> if PING is not what you would use, give us a better utility.
>
> In fact... EVERYONE ( okay 99.73 percent :-) uses PING. After all
> router LOAD is router LOAD.... and if a few ICMP packets can't get
> back in a subjectly reasonable time.. then DUH.... "da network
> is busy......" BGP updates take bandwidth just like any other packet.
>
> Of course the 0.27 percent, zen routing gods of the universe just
> feel the load and the harmonic BGP update patterns and PING between
> the BGP updates.... for a better answer.
>
> Sorry, I could not resist.... and apologize for the satire. PING!!
> PING!! PING!!
>
> Tim
>
> --
> +--------------------------------------------------------------------------+
> | Tim Bass | #include<campfire.h> |
> | Principal Network Systems Engineer | for(beer=100;beer>1;beer++){ |
> | The Silk Road Group, Ltd. | take_one_down(); |
> | | pass_it_around(); |
> | http://www.silkroad.com/ | } |
> | | back_to_work(); /*never reached */ |
> +--------------------------------------------------------------------------+
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