08-19-2009 12:27 PM - edited 03-06-2019 07:20 AM
Folks, I have two switches:
4507 (port f3/2)---- 3750 (port f0/23)
All of sudden I see intefaces on 4507 f3/2 up/down. I go to 4507 and I see that the switchport f3/2 has some input errors and CRC errors. Then I see on 3750 switchport fa0/23 got way more errors. Also, output from show tech on 4507 switch showed message " Aug 19 10:37:22.549: %DTP-5-NONTRUNKPORTON: STANDBY:Port Fa3/2 has become non-trunk
Aug 19 10:41:57.180: %DTP-5-TRUNKPORTON: Port Fa3/2 has become dot1q trunk...". I imagine that such status that the port was a non-trunk was due to a bad communication (bad cable or bad switchport), correct?
Also, do you agree that based on the fact that I have way more input errors and CRC errors on switchport fa0/23 on the 3750 I can conclude that if it is a faulty switchport that would be likely be on the 3750? I will try to replace the cables and see if the problem goes away. Let me know if you have other approach in mind based on the data provided.
3750#show int
(...)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
18682 packets input, 9509495 bytes, 0 no buffer
Received 18582 broadcasts (17576 multicast)
0 runts, 0 giants, 0 throttles
115699 input errors, 102042 CRC, 13657 frame, 0 overrun, 0 ignored
0 watchdog, 17576 multicast, 0 pause input
0 input packets with dribble condition detected
3750#show int f0/23 switchport
Name: Fa0/23
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: down
Administrative Trunking Encapsulation: dot1q
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 1 (default)
Voice VLAN: none
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: 2
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Protected: false
Appliance trust: none
4507#show int f3/2
FastEthernet3/2 is up, line protocol is down (notconnect)
(...)
Received 346732480 broadcasts (345361439 multicasts)
32 runts, 0 giants, 0 throttles
71 input errors, 39 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
20225802 packets output, 1643442465 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
4507#show int f3/2 switchport
Name: Fa3/2
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: down
Administrative Trunking Encapsulation: dot1q
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 1 (default)
Administrative Native VLAN tagging: enabled
Voice VLAN: none
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk associations: none
Administrative private-vlan trunk mappings: none
Operational private-vlan: none
Trunking VLANs Enabled: 2
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Solved! Go to Solution.
08-19-2009 12:33 PM
Your approach sounds overall correct.
Here is a useful doc for the CRC errors:
http://www.ciscotaccc.com/kaidara-advisor/lanswitching/showcase?case=K19375172
08-19-2009 12:33 PM
Your approach sounds overall correct.
Here is a useful doc for the CRC errors:
http://www.ciscotaccc.com/kaidara-advisor/lanswitching/showcase?case=K19375172
08-19-2009 04:12 PM
Verify port settings on each match , if one end is set as auto for speed and duplex then the other end "must" be set as auto also. Sounds like a speed/duplex mismtach.
08-19-2009 04:36 PM
It turned out it was a cable miswired. Once I asked to rebuild and repatch cable, things worked.
08-19-2009 06:58 PM
Great.
That is usually most of the times the issue. If no one touches the duplex settings, it wont happen.
Glad you resolved it.
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