Hello All -
I have a couple 3550XL's, one running 12.2(25)SEB4, the other 12.2(44)SE6. The ports are trunked and each has a Motorola Canopy AP connected with 900Mhz Subscriber Modules providing wifi using Cisco Meraki devices. I have hard coded each ports duplex and speed to full/100 and swapped cables on a couple of the ports, yet they are continually flapping with the %LINEPROTO-5-UPDOWN and %LINK-3-UPDOWN errors in the logs.
This happens all throughout the day, every day. What could cause the flapping if I've hard coded each end and verified the cables are good? Attached is the running config for the ports in question. Let me know if there's any other info needed. Thanks!
FastEthernet0/44 is up, line protocol is up (connected) 23446 input errors, 23446 CRC, 0 frame, 0 overrun, 0 ignored
Can you post the output to the command "sh controll e F0/44"?
Thanks so much for your help. See below.
Transmit FastEthernet0/44 Receive
1440836103 Bytes 2926725407 Bytes
18585176 Unicast frames 12086477 Unicast frames
4229831 Multicast frames 30300 Multicast frames
5376566 Broadcast frames 132542 Broadcast frames
137 Discarded frames 1276 No dest, unicast
0 Too old frames 5 No dest, multicast
0 Deferred frames 337 No dest, broadcast
0 1 collision frames
0 2 collision frames 24067 FCS errors
0 3 collision frames 0 Oversize frames
0 4 collision frames 0 Undersize frames
0 5 collision frames 197845 Collision fragments
0 6 collision frames
0 7 collision frames 1126737 Minimum size frames
0 8 collision frames 7486954 65 to 127 byte frames
0 9 collision frames 1839745 128 to 255 byte frames
0 10 collision frames 180254 256 to 511 byte frames
0 11 collision frames 220001 512 to 1023 byte frames
0 12 collision frames 1268893 1024 to 1518 byte frames
0 13 collision frames
0 14 collision frames 0 Flooded frames
0 15 collision frames 0 Overrun frames
0 Excessive collisions 9 VLAN filtered frames
0 Late collisions 0 Source routed frames
0 Good (1 coll) frames 0 Valid oversize frames
0 Good(>1 coll) frames 0 Pause frames
0 Pause frames 31 Symbol error frames
0 VLAN discard frames 0 Invalid frames, too large
0 Excess defer frames 0 Valid frames, too large
0 Too large frames 197941 Invalid frames, too small
6010850 64 byte frames 152355 Valid frames, too small
4564201 127 byte frames
1977112 255 byte frames
943661 511 byte frames
300834 1023 byte frames
14394915 1518 byte frames
Please check the entire cable length to whatever is connected to port 44. You've got a cable problem. The output has high amount of FCS and collision fragments which are normally attributed to a faulty cable.
if you have only one Switch in network then try to t-shoot Leo has explained, if you have more than one switch in network then pls check STP on VLAN.
Hi Nafis -
I did replace the cable and alleviated the input/CRC errors, yet we're still seeing the flapping occur. I've attached the sh span. Is it possible that clients roaming from one AP to another on property could cause a false-positive loop? If the switch doesn't see that a device left one AP and connected to another, would it see that as a loop?
As i found in show span output this switch is not root switch so go to the root switch and run the below mention command, after that send the show span output
spanning-tree vlan 1-20 root primary