Errors on Cisco WS-C2950T-24 switch FastEthernet port

[vladimir-simic]

SW1#show interfaces fastEthernet 0/14 counters errors

Port        Align-Err    FCS-Err   Xmit-Err    Rcv-Err UnderSize

Fa0/14           6682     140364          0     306468         0

Port      Single-Col Multi-Col  Late-Col Excess-Col Carri-Sen     Runts    Giants

Fa0/14             0         0         0          0    180103         0      2798

SW1#show interfaces fastethernet 0/14

FastEthernet0/14 is down, line protocol is down (err-disabled)

  Hardware is Fast Ethernet, address is 0015.6204.1fce (bia 0015.6204.1fce)

  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

     reliability 172/255, txload 1/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Auto-duplex, Auto-speed, media type is 100BaseTX

  input flow-control is unsupported output flow-control is unsupported

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

  Last input never, output 3d00h, output hang never

  Last clearing of "show interface" counters never

  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 0 bits/sec, 0 packets/sec

  5 minute output rate 0 bits/sec, 0 packets/sec

     131027136 packets input, 2935317548 bytes, 0 no buffer

     Received 7643 broadcasts (0 multicast)

     0 runts, 2798 giants, 0 throttles

     149844 input errors, 140364 CRC, 6682 frame, 0 overrun, 0 ignored

     0 watchdog, 5267 multicast, 0 pause input

     0 input packets with dribble condition detected

     75240868 packets output, 1154829616 bytes, 0 underruns

     0 output errors, 0 collisions, 4 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

What is problem with this port?

[Jan Rolny]

Hi Vladimir,

on first look your interface seems to be err-diabled (first line)

FastEthernet0/14 is down, line protocol is down (err-disabled)

Please look to syslog for reason why interface is err-disabled. There can be number of reasons. Please post running config of interface. Do you have security applied to interface?

Regards,

Jan

[vladimir-simic]

My configuration interface Fa0/14:

interface FastEthernet0/14

switchport access vlan 100

switchport mode access

mls qos trust device cisco-phone

mls qos trust cos

auto qos voip cisco-phone

spanning-tree portfast

[Jan Rolny]

Hi Vladimir,

are you able to check syslog messages? You should see reason in syslog. Please read this document to check all the resons mentioned:

http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a00806cd87b.shtml

Jan

[barweiss45]

With the information provided and the way you have the interfaced configured I'm assuming this is an access port with some host connected to it (phone, PC, both perhaps). Since portfast disables BPDU's on the the interface I don't think you have a spanning tree issue causing the interface to go err-disable, especially if it is truly an access port connected to a non-switch device. My guess is a possible duplex mis-match. If the other side is hard coded to full duplex then int fa0/14 will fall back to half duplex as duplex is not negotiated. If the duplex is auto then on the host, the its possible you have a physical layer issue. At that point you'll have to trouble each physical compent to determine the issue (the NIC on the host, the cable, the port on the switch, etc).

[Leo Laohoo]

 reliability 172/255, txload 1/255, rxload 1/255

Your line error is possibly caused by an execessive amount of "line flaps".  This is evident with the output.  Under "reliabiltiy" the values should be 255/255 and nothing LESS.