[c-nsp] Interface output

[Michael Malitsky]

Now, why doesn't TAC know about this?  I've just opened a ticket with
the exact same question.  It took them 2+ days to arrive at a similar
answer (with a lot less certainty and detail), and in between they've
produced random guesses ranging from "your IOS is too new and this is a
cosmetic problem" to "bad cable".
One outstanding question - how does one clear this counter?  "clear
counters" doesn't do the job (clears everything else fine).

Michael

> Message: 7
> Date: Thu, 4 Oct 2007 15:39:43 -0400
> From: Rodney Dunn <rodunn at cisco.com>
> Subject: Re: [c-nsp] Interface output
> To: Ahmad Cheikh-Moussa <acm at netuse.de>
> Cc: cisco-nsp at puck.nether.net
> Message-ID: <20071004193943.GB9431 at rtp-cse-489.cisco.com>
> Content-Type: text/plain; charset=us-ascii
> 
> Cisco IOS software keeps track of per-interface counters for 
> unknown protocol drops. However,
> these per-interface counters, that record packets with 
> unknown (or unconfigured) protocol 
> received, are not displayed in the <cmdBold>show 
> interfaces<nocmdBold> command.
> This is a request to display  those counters to aid in 
> troubleshooting.
> Alternatively, the number of unknown protocol drops can be 
> retrieved through SNMP under the
> MIB variable "ifInUnknownProtos", and the commands 
> <cmdBold>show interfaces 
> switching<nocmdBold> and <cmdBold>show interfaces 
> stats<nocmdBold> display per-protocol
> counters including an "Other" category, which might be used 
> as well. However, using this second
> method through the CLI gives more packets than actually 
> "dropped due to unknown protocol".
> It can serve as an indication, but the only workaround is to 
> use SNMP and poll for 
> "ifInUnknownProtos".
> 
> Interesting in your output you got 300 broadcast and 300 
> unknown protocol
> drops. Maybe get a sniffer and correlate.
> 
> On Thu, Oct 04, 2007 at 08:28:51PM +0200, Ahmad Cheikh-Moussa wrote:
> > Hi!
> > 
> > Can someone tell me, what it means, if I have "unknown 
> protocol drops" ?
> > I've got no packet loss. The speed is good too. 
> > The cisco output interpreter says everything is ok.
> > 
> > Here the output of show interface :
> > #sh int fastEthernet 0/1
> > FastEthernet0/1 is up, line protocol is up
> >   Hardware is Gt96k FE, address is 001b.d5ab.f0d5 (bia 
> 001b.d5ab.f0d5)
> >   Description: 
> >   Internet address is x.x.x.x/28
> >   MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
> >      reliability 255/255, txload 1/255, rxload 1/255
> >   Encapsulation ARPA, loopback not set
> >   Keepalive set (10 sec)
> >   Full-duplex, 10Mb/s, 100BaseTX/FX
> >   ARP type: ARPA, ARP Timeout 04:00:00
> >   Last input 00:00:51, output 00:00:02, output hang never
> >   Last clearing of "show interface" counters never
> >   Input queue: 0/75/0/0 (size/max/drops/flushes); Total 
> output drops: 0
> >   Queueing strategy: fifo
> >   Output queue: 0/40 (size/max)
> >   5 minute input rate 0 bits/sec, 0 packets/sec
> >   5 minute output rate 0 bits/sec, 0 packets/sec
> >      301 packets input, 109560 bytes
> >      Received 300 broadcasts, 0 runts, 0 giants, 0 throttles
> >      0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
> >      0 watchdog
> >      0 input packets with dribble condition detected
> >      1834 packets output, 110550 bytes, 0 underruns
> >      0 output errors, 0 collisions, 5 interface resets
> >      300 unknown protocol drops
> >      0 babbles, 0 late collision, 0 deferred
> >      0 lost carrier, 0 no carrier
> >      0 output buffer failures, 0 output buffers swapped out
> > 
> > 
> > 
> > Any ideas ?
> > 
> > Regards,
> >  Ahmad
> > 
> > 
> > -- 
> > Ahmad Cheikh-Moussa 
> > NetUSE AG
> > Dr.-Hell-Stra?e, 24107 Kiel, Germany
> > Telefon: +49 431 2390 400 --  Telefax: +49 431 2390 499
> > Service: Service at NetUSE.DE --  http://NetUSE.DE/