[c-nsp] Troubleshooting Input Queue Drops on 7600 running 12.2(33)SRC5

Devon True devon at noved.org
Thu Jul 1 09:49:04 EDT 2010


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 6/30/2010 2:00 PM, Rodney Dunn wrote:
> You could try the 'debug ip cef packet' on the RP, as it captures only
> sw switched traffic, and it has rate limiting ability built in it.

I ran 'debug ip cef packet g1/1/1 input rate 5 detail' and watched the
counter from 'sh int g1/1/1 switching | inc Drops' till it increased.
Once I saw the increase I looked at the logs but all I see is various
bogon IPs (10/8, 192.168/16, etc) trying to hit various hosts. I imagine
I see them due to an ACL applied to Gi1/1/1.

What should I be looking for? I did notice the 'giants' counter matched
the input drops so I looked for large packets based on the 'length=',
but they were all 56, 48, 40, etc.

Jul  1 13:42:05 ROUTER debug 3947: Jul  1 09:42:04.227 Eastern:
CEF-Debug: Packet from 172.18.240.146 (Gi1/1/1) to x.x.x.x
Jul  1 13:42:05 ROUTER debug 3948: Jul  1 09:42:04.227 Eastern:
ihl=20, length=56, tos=0, ttl=245, checksum=46543, offset=0
Jul  1 13:42:05 ROUTER debug 3949: Jul  1 09:42:04.227 Eastern:     ICMP
type=11, code=0, checksum=43185
Jul  1 13:42:05 ROUTER debug 3950: Jul  1 09:42:04.227 Eastern:
 TTL expired
Jul  1 13:42:05 ROUTER debug 3951: Jul  1 09:42:04.819 Eastern:
CEF-Debug: Packet from 172.18.240.10 (Gi1/1/1) to x.x.x.x
Jul  1 13:42:05 ROUTER debug 3952: Jul  1 09:42:04.823 Eastern:
ihl=20, length=56, tos=0, ttl=244, checksum=41657, offset=0
Jul  1 13:42:05 ROUTER debug 3953: Jul  1 09:42:04.823 Eastern:     ICMP
type=11, code=0, checksum=49523
Jul  1 13:42:05 ROUTER debug 3954: Jul  1 09:42:04.823 Eastern:
 TTL expired

- --
Devon

> On 6/30/10 11:30 AM, Devon True wrote:
> All:
> 
> I am seeing increasing input queue drops on a 7600 running 12.2(33)SRC5
> on a SPA-2X1GE in a 7600-SIP-400.
> 
> #sh int g1/1/1
> GigabitEthernet1/1/1 is up, line protocol is up
>    Hardware is GigEther SPA, address is 001d.7170.3500 (bia
> 001d.7170.3500)
>    Description:
>    Internet address is x.x.x.x/yy
>    MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
>       reliability 255/255, txload 72/255, rxload 46/255
>    Encapsulation ARPA, loopback not set
>    Keepalive not supported
>    Full Duplex, 1000Mbps, link type is force-up, media type is SX
>    output flow-control is unsupported, input flow-control is unsupported
>    ARP type: ARPA, ARP Timeout 04:00:00
>    Last input 00:00:00, output 00:00:00, output hang never
>    Last clearing of "show interface" counters 01:44:10
>    Input queue: 0/75/1707/0 (size/max/drops/flushes); Total output
> drops: 0
>    Queueing strategy: fifo
>    Output queue: 0/40 (size/max)
>    5 minute input rate 183245000 bits/sec, 41346 packets/sec
>    5 minute output rate 283924000 bits/sec, 55078 packets/sec
>       256319513 packets input, 149816057859 bytes, 0 no buffer
>       Received 5 broadcasts (0 IP multicasts)
>       0 runts, 1707 giants, 0 throttles
>       1707 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
>       0 watchdog, 0 multicast, 0 pause input
>       308870586 packets output, 193458081331 bytes, 0 underruns
>       0 output errors, 0 collisions, 0 interface resets
>       0 babbles, 0 late collision, 0 deferred
>       0 lost carrier, 0 no carrier, 0 pause output
>       0 output buffer failures, 0 output buffers swapped out
> 
> I also ran "sh int g1/1/1 switching" and it looks like the RP is
> dropping the packets.
> 
> #sh int g1/1/1 switching
> GigabitEthernet1/1/1
>            Throttle count          0
>          Drops         RP       1706         SP          0
>    SPD Flushes       Fast          0        SSE          0
>    SPD Aggress       Fast          0
>   SPD Priority     Inputs       7257      Drops          0
> 
>       Protocol       Path    Pkts In   Chars In   Pkts Out  Chars Out
>          Other    Process          0          0          0          0
>              Cache misses          0
>                      Fast          0          0          0          0
>                 Auton/SSE      15978     958680          0          0
>             IP    Process   80379934 7498092736   42273104 3084247027
>              Cache misses          0
>                      Fast   68341283 5017154676    1197481   86714780
>                 Auton/SSE 401843915443 245108148367129 516300637842
> 386876899705145
>        DEC MOP    Process          0          0      31700    2440900
>              Cache misses          0
>                      Fast          0          0          0          0
>                 Auton/SSE          0          0          0          0
>            ARP    Process      15978     958680      15866     951960
>              Cache misses          0
>                      Fast          0          0          0          0
>                 Auton/SSE          0          0          0          0
> 
> Any advice on troubleshooting? I looked at
> http://www.cisco.com/en/US/products/hw/routers/ps133/products_tech_note09186a0080094791.shtml
> 
> and "show buffers input-interface g1/1/1 header" does not display any
> data and performing "debug ip packet" on a production router may not be
> in my best interests. :)
> 
_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.12 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iEYEARECAAYFAkwsnNAACgkQWP2WrBTHBS/oGACg3H/BJyzwbeFeoieAodkPVBv5
1/AAoK97sTk30Qp9TgaWkISRQOfJVJ/G
=FSET
-----END PGP SIGNATURE-----


More information about the cisco-nsp mailing list