runts on a Fibre-Connection (trunk)

[mig]

My problem is on a fibre-connection (trunk) with dot1q enc. between a C2970 and a C4506. The interface on the 2970 counts rcv-err and runts. The interface on the 4506 counts no errors. The Speed and Duplex is on both interface 1000-FULL.

The output of "sh int" on the 2970:

GigabitEthernet0/25 is up, line protocol is up (connected)

Hardware is Gigabit Ethernet, address is 000d.bd73.4499 (bia 000d.bd73.4499)

MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 1000Mb/s, link type is auto, media type is SX

output flow-control is off, input flow-control is off

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:00, output 00:00:01, output hang never

Last clearing of "show interface" counters 01:07:27

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

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 6770000 bits/sec, 1369 packets/sec

5 minute output rate 4176000 bits/sec, 1303 packets/sec

7101027 packets input, 4130056493 bytes, 0 no buffer

Received 206997 broadcasts (0 multicast)

1642 runts, 0 giants, 0 throttles

1642 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog, 117566 multicast, 0 pause input

0 input packets with dribble condition detected

6419054 packets output, 3700505598 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

The output of "sh int" on the 4506:

GigabitEthernet2/2 is up, line protocol is up (connected)

Hardware is Gigabit Ethernet Port, address is 000f.2494.d471 (bia 000f.2494.d471)

Description: to VIES251 (Serverraum)

MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 1000Mb/s, link type is auto, media type is SX

output flow-control is off, input flow-control is off

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:00, output never, output hang never

Last clearing of "show interface" counters 01:01:52

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 5515000 bits/sec, 1140 packets/sec

5 minute output rate 4031000 bits/sec, 1230 packets/sec

5997252 packets input, 3555061669 bytes, 0 no buffer

Received 11572 broadcasts (8501 multicast)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 input packets with dribble condition detected

6665829 packets output, 3830530780 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 output buffer failures, 0 output buffers swapped out

What can be the cause of this errors?

Maybe the fibre-cable? Or the GBICs?

thanks!

mig

[Kevin Dorrell]

This looks a bit like bug CSCec14238, although that is a different platform:

When using dot1q on trunk interface on the Cat3750, runts may be seen on show interface output because valid dot1q encapsulated packets which are 61-64 bytes including the q-tag are counted by the Cat3750 as undersized frames, even though these packets are forwarded correctly. In addition, these packets are not reported in the appropriate category (unicast,

multicast, broadcast) in receive statistics.

http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCec14238

Kevin Dorrell

Luxembourg

[mig]

Hi Kevin,

thanks for your help.

I also found this bug before I posted my problem. But it is a different platform, do you think this is possible?

What is your experience?

thanks

mig

[amikat]

Hi,

This is known issue.

The problem is resolved in the following releases of Cisco IOS software:

Cisco IOS release 12.1(19)EA1d

Cisco IOS release 12.1(20)EA1a

Cisco IOS release 12.1(22)EA1 or later

Cisco IOS release 12.2(20)SE1 or later

It is not necessary to upgrade to one of the fixed releases, as this problem is purely cosmetic and does not affect the functionality of the device. However, the false display of errors will not occur if an upgrade to one of these releases is performed.

Best regards,

Antonin

[mig]

Hi,

a known issue on the Cat2970 platform? I think only

on the Cat3750.

Which bug-id describes this problem on the C2970?

thanks

mig

[amikat]

Hi,

Products Affected:

C2970, C3560, C3750, C3750-ME.

Best regards,

Antonin

[amikat]

Hi,

This is the document:

http://www.cisco.com/en/US/products/hw/switches/ps5206/products_field_notice09186a00802cac62.shtml

Best regards,

Antonin