sh int counters errors

[tedauction]

Hello, if I run the command 'sh int counters errors' I see that port Gi0/13 is experiencing a lot of undersize packets. Will these packets be getting dropped ? and are they in the inbound or outbound direction ?

Secondly, when I run the command sh int Gi0/13, I do not see any reference to those undersize errors ?

Should I also be able to see something from the command 'sh int gi0/13' relating to these undersize errors (e.g. runts?) or do I need to run both of these commands in the future to get the full picture of interface problems ?

mySwitch#sh int counters errors

Port Align-Err FCS-Err Xmit-Err Rcv-Err UnderSize
Gi0/1 0 0 0 0 0
Gi0/2 0 0 0 0 0
Gi0/3 0 0 0 0 0
Gi0/4 0 0 0 0 0
Gi0/5 0 0 0 0 0
Gi0/6 0 0 0 0 0
Gi0/7 0 0 0 0 0
Gi0/8 0 0 0 0 0
Gi0/9 0 0 0 0 0
Gi0/10 0 0 0 0 0
Gi0/11 0 0 0 0 0
Gi0/12 0 0 0 0 0
Gi0/13 0 0 0 0 4685466
Gi0/14 0 0 0 0 0
Gi0/15 0 0 0 0 0
Gi0/16 0 0 0 0 0
Gi0/17 0 0 0 0 0
Gi0/18 0 0 0 0 0
Gi0/19 0 0 0 0 0
Gi0/20 0 0 0 0 0
Gi0/21 0 0 0 0 0
Gi0/22 0 0 0 0 0
Gi0/23 0 0 0 0 0

MySwitch#sh int gi0/13
GigabitEthernet0/13 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 9caf.cabb.b08d (bia 9caf.cabb.b08d)
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 2/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 00:00:00, output hang never
Last clearing of "show interface" counters 17:21:36
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 10977000 bits/sec, 1036 packets/sec
5 minute output rate 1114000 bits/sec, 671 packets/sec
11879307 packets input, 14391710688 bytes, 0 no buffer
Received 0 broadcasts (0 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
12933350 packets output, 3947230212 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

[Leo Laohoo]

Kindly post the complete output to the command "sh controll e g0/13".

[tedauction]

Hello, thanks for your assistance:

mySwitch#sh controll e g0/13

Transmit GigabitEthernet0/13 Receive
2765088203 Bytes 1824868766 Bytes
3018925967 Unicast frames 1621510440 Unicast frames
116579341 Multicast frames 8 Multicast frames
43130698 Broadcast frames 194 Broadcast frames
0 Too old frames 1552815506 Unicast bytes
0 Deferred frames 752 Multicast bytes
0 MTU exceeded frames 12416 Broadcast bytes
0 1 collision frames 0 Alignment errors
0 2 collision frames 0 FCS errors
0 3 collision frames 0 Oversize frames
0 4 collision frames 1647482807 Undersize frames
0 5 collision frames 0 Collision fragments
0 6 collision frames
0 7 collision frames 675856 Minimum size frames
0 8 collision frames 838859914 65 to 127 byte frames
0 9 collision frames 288774487 128 to 255 byte frames
0 10 collision frames 335583470 256 to 511 byte frames
0 11 collision frames 235690978 512 to 1023 byte frames
0 12 collision frames 4216893233 1024 to 1518 byte frames
0 13 collision frames 0 Overrun frames
0 14 collision frames 0 Pause frames
0 15 collision frames
0 Excessive collisions 0 Symbol error frames
0 Late collisions 0 Invalid frames, too large
0 VLAN discard frames 0 Valid frames, too large
0 Excess defer frames 0 Invalid frames, too small
4098224768 64 byte frames 1647482807 Valid frames, too small
1655239891 127 byte frames
333702197 255 byte frames 0 Too old frames
301070267 511 byte frames 0 Valid oversize frames
212766056 1023 byte frames 0 System FCS error frames
872600123 1518 byte frames 0 RxPortFifoFull drop frame
0 Too large frames
0 Good (1 coll) frames
0 Good (>1 coll) frames

[Leo Laohoo · Accepted solution]

There is nothing wrong here.

[Brian Beijl · Accepted solution]

Hi,

There are a number of reasons for runt packets. They shouldn't occur on a normal and healthy network. Since this is only happening at one port, I suggest replacing the cable if possible, and also run the TDR test to check if it looks normal:

test cable tdr interface Gi0/13
show cable tdr interface Gi0/13

Since this is an Gigabit port, all cable pairs should have the state Normal. Anything other than that is an indication that something is wrong:

Under “Pair status” you can get the following results:

Result	Explaination
Normal	Ideal result you want. If testing FastEthernet, you want Pair A and B as “Normal”. If testing GigabitEthernet, you want ALL as “Normal”.
Open	Open circuit. This means that one (or more) pair has “no pin contact”.
Short	Short circuit.
Impedance Mismatched	Bad cable.

Even if this tests out as Normal, there still might be something wrong with the cable, so even then I would suggest to replace the cable, or plug the machine in another switchport.