[c-nsp] NPE-G1 Interface errors / packetloss

[Michael K. Smith - Adhost]

> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-
> bounces at puck.nether.net] On Behalf Of Alexander Fossa
> Sent: Thursday, September 29, 2011 8:10 AM
> To: cisco-nsp ‎[cisco-nsp at puck.nether.net]‎
> Subject: [c-nsp] NPE-G1 Interface errors / packetloss
> 
> Hi,
> 
> We've been trying to diagnose a packetloss issue though one of our LNS's.
> 
> The NPE-G1 is connected directly to a SUP32 with traffic in the region of
> 50mbit.
> 
> At first we thought it was a dirty fibre / failed SFP, both have been replaced
> but the problem continues.
> 
> We then moved the main infrastructure VLAN off Gi0/3 to Gi0/1, hence
> ruling out the SUP32 port and the physical port on the NPE-G1. The errors
> followed....
> 
> I've been doing quite a bit of reading and think this might be something to do
> with microbursts.... but we've not had an increase in traffic, if anything a
> decrease.
> 
> Show interface stats from NPE-G1
> 
> GigabitEthernet0/1 is up, line protocol is up
>   Hardware is BCM1250 Internal MAC, address is 0008.203e.441b (bia
> 0008.203e.441
> b)
>   Description: Link to BEDGE1.THE GI1/7
>   MTU 9216 bytes, BW 1000000 Kbit, DLY 10 usec,
>      reliability 255/255, txload 5/255, rxload 4/255
>   Encapsulation 802.1Q Virtual LAN, Vlan ID  1., loopback not set
>   Keepalive set (10 sec)
>   Full-duplex, 1000Mb/s, media type is RJ45
>   output flow-control is XON, input flow-control is XON
>   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 16:39:10
>   Input queue: 0/1500/97/4 (size/max/drops/flushes); Total output drops: 0
>   Queueing strategy: fifo
>   Output queue: 0/40 (size/max)
>   5 minute input rate 18801000 bits/sec, 4990 packets/sec
>   5 minute output rate 21289000 bits/sec, 5288 packets/sec
>      152579806 packets input, 2828997929 bytes, 0 no buffer
>      Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
>      0 input errors, 0 CRC, 0 frame, 142 overrun, 0 ignored
>      0 watchdog, 265811 multicast, 0 pause input
>      0 input packets with dribble condition detected
>      161805464 packets output, 4109563833 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
> DSL1.THE#
> 
> Show interface stats from SUP32
> 
> edge1.the#sh int gi1/7
> GigabitEthernet1/7 is up, line protocol is up (connected)
>   Hardware is C6k 1000Mb 802.3, address is 0016.465e.3732 (bia
> 0016.465e.3732)
>   Description: DSL1.THE_GI0/1
>   MTU 9216 bytes, BW 1000000 Kbit, DLY 10 usec,
>      reliability 255/255, txload 4/255, rxload 5/255
>   Encapsulation ARPA, loopback not set
>   Keepalive set (10 sec)
>   Full-duplex, 1000Mb/s, media type is T
>   input flow-control is off, output flow-control is off
>   Clock mode is auto
>   ARP type: ARPA, ARP Timeout 04:00:00
>   Last input 00:00:21, output never, output hang never
>   Last clearing of "show interface" counters 16:25:18
>   Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
>   Queueing strategy: fifo
>   Output queue: 0/40 (size/max)
>   5 minute input rate 21224000 bits/sec, 5233 packets/sec
>   5 minute output rate 19475000 bits/sec, 4943 packets/sec
>      160219198 packets input, 76742158873 bytes, 0 no buffer
>      Received 133662 broadcasts (133662 multicasts)
>      47 runts, 0 giants, 0 throttles
>      25065 input errors, 24986 CRC, 24939 frame, 0 overrun, 0 ignored
>      0 watchdog, 0 multicast, 0 pause input
>      0 input packets with dribble condition detected
>      151327463 packets output, 65370785219 bytes, 0 underruns
>      0 output errors, 0 collisions, 1 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
> edge1.the#
> 
> As you can see lots of CRC & Frame errors the SUP32 side, and a few
> overruns on the NPE-G1 side.
> 
> Any ideas / thoughts?
> 
> Thanks in advance,
> 
> Alex
> 

Hi Alex:

Couple of things.

1) Flow Control - it looks like your NPE-G1 is set to XON/XON and your SUP32 has flow control off.  I would disable flow control on the NPE-G1 to, if nothing else, make the sides match for testing.
2) Copper/Fiber? - you said you replaced fiber/SFP but the interface on both sides say this is a copper connection.  With that, I would check for distance issues, bad cable, etc.
3) If anything, it looks like the issue is coming from the NPE-G1 side, given the huge amount of errors on the SUP32.

Regards,

Mike