[c-nsp] Input (overrun) errors on PA-GE / 7204VXR

[Graham Wooden]

Hi Folks,

It seems that I am overloading the traffic ingress into a PA-GE interface on
one of my internet edge routers,  a 7204VXR
(NPE-400/512MB/advipservicesk9-mz.122-33.SRE4) without too much effort.

30 second counters shows the traffic not to be too bursty (as well as the 5
minute graphs), especially when the traffic leaving the other side are the
two FE interfaces (upstreams) on the I/O controller. Combined on those two
are maybe do about 20Mb each at different times.

Anything else I can look at, besides writing this off to be an issue of "too
much traffic inbound"? A NPE-400 with the PA-GE can't handle this low volume
of traffic?  Or do need to look at the physical layer first (which seems to
be OK).

The other end of the 1000LX is a C6509 (SUP720-3b), with the interface
sitting on a WS-X6516-GBIC.  That interface shows zero issues, and has input
flow-controll off (output is on).

I am trying not to spend the money on a NPE-G1, which seems way overkill
because the level of traffic beside so little.  Here is some output from the
7204VXR.

EBR1-ATL1#show running-config interface gi2/0
Building configuration...

Current configuration : 208 bytes
!
interface GigabitEthernet2/0
 description CR1-ATL1
 ip address nn.nn.nn.10 255.255.255.248
 ip flow ingress
 negotiation auto
 service-policy output SetDSCPVOIP
 hold-queue 768 in
 hold-queue 512 out
end

EBR1-ATL1#show interfaces gi2/0
GigabitEthernet2/0 is up, line protocol is up
  Hardware is WISEMAN, address is 0007.4f08.f438 (bia 0007.4f08.f438)
  Description: CR1-ATL1
  Internet address is nn.nn.nn.10/29
  MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full Duplex, 1000Mbps, link type is auto, media type is LX
  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 4w2d
  Input queue: 1/768/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/512 (size/max)
  5 minute input rate 490000 bits/sec, 363 packets/sec
  5 minute output rate 3180000 bits/sec, 447 packets/sec
     1664722579 packets input, 2698235750 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     47686 input errors, 0 CRC, 0 frame, 47686 overrun, 0 ignored
     0 watchdog, 2086826 multicast, 0 pause input
     2081482879 packets output, 3723382484 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     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
EBR1-ATL1#