Ignored and overrun packets on cisco 7204VXR

[radjen.chotoe]

I am seeing packets being ignored on GigabitEthernet0/0, but can't find any reason what the reason can be for that. So far calculated that about 3% of the traffic is being ignored. If it was caused by shortage of input buffers, I would expect to see increasing counters somewhere at no_buffer, but that is not the case. The average txload and rxload on the router is low all times.

#sh int g0/0
GigabitEthernet0/0 is up, line protocol is up
  Hardware is i82543 (Livengood), address is 0012.7f8a.8008 (bia 0012.7f8a.8008)
  Description: ;Link to NORISMP998 G5/2
  Internet address is 151.175.19.102/30
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 2/255, rxload 2/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, link type is autonegotiation, media type is SX
  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 8w2d
  Input queue: 0/75/522186/1117 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 11667000 bits/sec, 2319 packets/sec
  5 minute output rate 9377000 bits/sec, 2350 packets/sec
     578287458 packets input, 1706457701 bytes, 0 no buffer
     Received 3180106 broadcasts, 0 runts, 0 giants, 29 throttles
     14996651 input errors, 0 CRC, 0 frame, 519693 overrun, 14476958 ignored
     0 watchdog, 3180104 multicast, 0 pause input
     0 input packets with dribble condition detected
     353879313 packets output, 4190517063 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

#sh ver
Cisco Internetwork Operating System Software
IOS (tm) 7200 Software (C7200-IS-M), Version 12.3(18), RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2006 by cisco Systems, Inc.
Compiled Wed 15-Mar-06 19:16 by dchih
Image text-base: 0x60008AF4, data-base: 0x61CD4000

ROM: System Bootstrap, Version 12.2(4r)B2, RELEASE SOFTWARE (fc2)
BOOTLDR: 7200 Software (C7200-KBOOT-M), Version 12.3(15), RELEASE SOFTWARE (fc3)

NORISMP005 uptime is 36 weeks, 6 days, 6 hours, 40 minutes
System returned to ROM by power-on
System restarted at 08:21:24 UTC Thu Jun 9 2011
System image file is "disk0:c7200-is-mz.123-18.bin"

cisco 7204VXR (NPE400) processor (revision B) with 229376K/32768K bytes of memory.
Processor board ID 32576526
R7000 CPU at 350MHz, Implementation 39, Rev 3.3, 256KB L2 Cache
4 slot VXR midplane, Version 2.8

Last reset from power-on
G.703/E1 software, Version 1.0.
G.703/JT2 software, Version 1.0.
Bridging software.
X.25 software, Version 3.0.0.

PCI bus mb0_mb1 (Slots 0, 1, 3 and 5) has a capacity of 600 bandwidth points.
Current configuration on bus mb0_mb1 has a total of 490 bandwidth points.
This configuration is within the PCI bus capacity and is supported.

PCI bus mb2 (Slots 2, 4, 6) has a capacity of 600 bandwidth points.
Current configuration on bus mb2 has a total of 200 bandwidth points
This configuration is within the PCI bus capacity and is supported.

Please refer to the following document "Cisco 7200 Series Port Adaptor
Hardware Configuration Guidelines" on Cisco.com <http://www.cisco.com>
for c7200 bandwidth points oversubscription and usage guidelines.

1 Ethernet/IEEE 802.3 interface(s)
1 Gigabit Ethernet/IEEE 802.3 interface(s)
7 Serial network interface(s)
125K bytes of non-volatile configuration memory.

62976K bytes of ATA PCMCIA card at slot 0 (Sector size 512 bytes).
8192K bytes of Flash internal SIMM (Sector size 256K).
Configuration register is 0x2102

[Mandlenkosi Nkiwane]

Please take a look at this:

https://supportforums.cisco.com/docs/DOC-2613

It might give you an idea of what you are experiencing.

[radjen.chotoe]

Thx for the link. That is what I already understood, but wouldn't it make sense that the no-buffer counter would increase?

[Mandlenkosi Nkiwane · Accepted solution]

Yours is showing 0

578287458 packets input, 1706457701 bytes, 0 no buffer

In this case it means that you have to throttle the other end of the link since it is sending more packets that you interface can handle.

[radjen.chotoe]

Then I will have to find out how to tune the other side to slow down sending packets. Thx so far

[Joseph W. Doherty]

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Posting

radjen.chotoe@nl.ibm.com wrote:

Thx for the link. That is what I already understood, but wouldn't it make sense that the no-buffer counter would increase?

You're looking at the wrong "buffer" counter.

Input queue: 0/75/522186/1117 (size/max/drops/flushes); Total output drops: 0

Increasing the input queue depth might avoid some drops, but your underlying problem likely is the NPE400, which doesn't offer sufficient performance to handle a busy gig link.

If other interfaces are just serial interfaces and a single Ethernet, and their aggregate is less than 100 Mbps, running the gig interface at 100 Mbps might be one solution (although not possible, I believe, with the SX optics - can you switch to copper?).