[j-nsp] icmp problems tracing through m20's

[Harry Reynolds]

Yes, they should show up as ICMP drops. I have:

  .5			.6
r3------------------r4

     10.0.2.4/30

At r3:

root at r3% ping -l 100 10.0.2.6
PING 10.0.2.6 (10.0.2.6): 56 data bytes
.....................................................................
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.........ax/stddev = 0.642/1.757/41.217/3.911 ms

At r4:
[edit]
lab at r4# run show system statistics | find icmp
icmp:
        173 drops due to rate limit <<<
        0 calls to icmp_error
        0 errors not generated because old message was icmp
        Output histogram:
                echo reply: 25703
        0 messages with bad code fields
        0 messages less than the minimum length
        0 messages with bad checksum


[edit]
lab at r4# run show system statistics | find icmp
icmp:
        181 drops due to rate limit <<<
        0 calls to icmp_error
        0 errors not generated because old message was icmp
        Output histogram:
                echo reply: 28611
        0 messages with bad code fields
        0 messages less than the minimum length
        0 messages with bad checksum
        0 messages with bad source address
        0 messages with bad length
        0 echo drops with broadcast or multicast destinaton address

Are there any policed discard occuring on the interface being pinged?

[edit]
lab at r4# run show interfaces so-0/1/0 extensive | match polic
    Errors: 0, Drops: 0, Framing errors: 0, Runts: 0, Giants: 0,
Bucket drops: 0, Policed discards: 0,
    Policing bucket: Disabled




> -----Original Message-----
> From: David Brazewell [mailto:davidb at ednet.co.uk]
> Sent: Thursday, May 22, 2003 11:21 AM
> To: Harry Reynolds
> Cc: juniper-nsp at puck.nether.net
> Subject: RE: [j-nsp] icmp problems tracing through m20's
>
>
>
>
> would this rate limiting show up in "show system statistics icmp"?
>
> cos Ive got the following on this router:
>
>         0 drops due to rate limit
>
> Cheers
>
> david
>
>
> On Thu, 22 May 2003, Harry Reynolds wrote:
>
> > Hello,
> >
> > I have not messed with mtr, but can confirm that ICMP
> rate limiting
> > on the fxp1 interface will result in some packet loss
> when performing
> > rapid (flood) pings that are destined to a PFE interface (this
> > traffic must transit fxp1). A recent email indicated
> these parameters
> > are now in effect; I have not confirmed:
> >
> > The default rate limiting is 50 per second per logical interface
> > and I think 500 per box per second.
> >
> >
> >
> > > -----Original Message-----
> > > From: juniper-nsp-bounces at puck.nether.net
> > > [mailto:juniper-nsp-bounces at puck.nether.net]On Behalf Of
> > > David Brazewell
> > > Sent: Thursday, May 22, 2003 11:00 AM
> > > To: juniper-nsp at puck.nether.net
> > > Subject: [j-nsp] icmp problems tracing through m20's
> > >
> > >
> > >
> > > Hi
> > >
> > > has anyone ever experienced problems where icmp traces
> > > (using mtr) to
> > > destinations through an m20 show no packet loss at the
> > > last hop but
> > > varying amounts of packet loss on one of the juniper
> interfaces?
> > >
> > > tracing to the juniper itself shows no packet loss.
> > >
> > > It has been suggested that this may be down to default
> > > icmp throttling on
> > > the junipers. does anyone know anything about this?
> > >
> > > Thanks
> > >
> > > David
> > >
> > >
> > > _______________________________________________
> > > juniper-nsp mailing list juniper-nsp at puck.nether.net
> > > http://puck.nether.net/mailman/listinfo/juniper-nsp
> >
> > --
> > Virus scanned by edNET.
> >
>