[c-nsp] IOS-XR and interface discards (input)

[Hank Nussbacher]

At 11:30 15/05/2015 -0700, Andrew Miehs wrote:

Thanks for all the feedback and links.  The person who came up with the 
solution was Tom:

>" ipv4 unreachables disable”
>
>I believe that XR counts packets that it needs to respond to with an 
>unreachable as a input drop, since these are disabled.
>Once I disabled this command I stopped seeing input drop counters on our 
>interface increment.

We disabled this command and the discards disappeared immediately.

Regards,
Hank


>Discards is probably acl/ control plane acl, full buffers on egress port/ 
>fabric.
>
>Not familiar with the platform so cant provide more info.
>
>Sent from a mobile device
>
> > On 15 May 2015, at 01:02, Alexandr Gurbo <gurbo at golas.ru> wrote:
> >
> > Hello,
> >
> > Check you fiber connection.
> >
> >
> > On Thu, 14 May 2015 22:04:35 +0300
> > Hank Nussbacher <hank at efes.iucc.ac.il> wrote:
> >
> >> We have an ASR 9010 running IOS-XR v 5.1.3.  We see a high level of input
> >> discards:
> >>
> >> TenGigE0/1/1/7 is up, line protocol is up
> >>   Interface state transitions: 25
> >>   Layer 1 Transport Mode is WAN
> >>   MTU 9028 bytes, BW 10000000 Kbit (Max: 10000000 Kbit)
> >>      reliability 255/255, txload 13/255, rxload 99/255
> >>   Encapsulation ARPA,
> >>   Full-duplex, 10000Mb/s, link type is force-up
> >>   output flow control is on, input flow control is on
> >>   Carrier delay (up) is 100 msec, Carrier delay (down) is 4000 msec
> >>   loopback not set,
> >>   ARP type ARPA, ARP timeout 04:00:00
> >>   Last input 00:00:00, output 00:00:00
> >>   Last clearing of "show interface" counters 1d13h
> >>   30 second input rate 3886868000 bits/sec, 392410 packets/sec
> >>   30 second output rate 527057000 bits/sec, 154557 packets/sec
> >>      55223825999 packets input, 63505398737673 bytes, 116320028 total
> >> input drops
> >>      0 drops for unrecognized upper-level protocol
> >>      Received 111 broadcast packets, 1499584 multicast packets
> >>               0 runts, 0 giants, 0 throttles, 0 parity
> >>      10 input errors, 5 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
> >>
> >> The config on the interface looks like this:
> >>
> >> interface TenGigE0/1/1/7
> >>  mtu 9028
> >>  ipv4 unreachables disable
> >>  ipv6 nd dad attempts 5
> >>  ipv6 address 2001:798:28:20aa::6/126
> >>  monitor-session No1 ethernet
> >>  flow-control bidirectional
> >>  carrier-delay up 100 down 4000
> >>  load-interval 30
> >>  flow ipv4 monitor fmp-nfsen sampler fsm-nfsen ingress
> >>  transport-mode wan
> >>  ipv4 access-group catch13-ing ingress
> >> !
> >>
> >> Any clue would be helpful for us to begin to debug this issue.
> >>
> >> Thanks,
> >> Hank
> >>
> >> _______________________________________________
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> >
> >
> > --
> > Alexandr Gurbo
> > _______________________________________________
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