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New Member

3560 switchport amber/green alternating

Just wanted to through this out there to see if anyone else had experienced this. I have a switchport on a 3560 connected to a 2651XM router via dot1q trunk protocal. The switchport is alternating back and forth between green and amber. I have turned off online power to the switch port and the port went to green for about 10 seconds and then resumed the green/amber alternating state. If anyone has run accross this and could shed any light that would be great. Thanks

Hall of Fame Super Bronze

Re: 3560 switchport amber/green alternating


The port is showing any errors ?

Can we see the config from both devices ?

New Member

Re: 3560 switchport amber/green alternating

Here is the router's switch port.

interface FastEthernet0/0

no ip address

speed 100



interface FastEthernet0/0.1

description Charles Barker Data VLAN

encapsulation dot1Q 1 native

ip address

ip pim sparse-dense-mode


interface FastEthernet0/0.2

description Charles Barker CCM VLAN

encapsulation dot1Q 2

ip address

ip pim sparse-dense-mode

no cdp enable


interface FastEthernet0/0.3

description Connection to IPT Phone VLAN

encapsulation dot1Q 3

ip address

ip helper-address

ip pim sparse-dense-mode



interface FastEthernet0/3

description Connection to r2.vabeach-toy.charlesbarker fa00 (VLAN 1 VLAN 2 and VLAN 3) (Cisco 2651)

switchport trunk encapsulation dot1q

switchport mode trunk

no ip address

duplex full

speed 100

priority-queue out

no mdix auto

power inline never


s3.vabeach-toy.charlesbarker#sho int fa0/3

FastEthernet0/3 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0011.2122.9985 (bia 0011.2122.9985)

Description: Connection to r2.vabeach-toy.charlesbarker fa00 (VLAN 1 VLAN 2 and VLAN 3) (Cisco 2651)

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

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

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 100Mb/s

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

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

Last input 00:00:39, output 00:00:01, 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 295000 bits/sec, 232 packets/sec

5 minute output rate 307000 bits/sec, 253 packets/sec

733200638 packets input, 1532289110 bytes, 0 no buffer

Received 437630462 broadcasts (0 multicast)

13 runts, 0 giants, 0 throttles

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

0 watchdog, 437629992 multicast, 0 pause input

0 input packets with dribble condition detected

698508387 packets output, 4108603362 bytes, 0 underruns

0 output errors, 0 collisions, 1 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

If you need anything else just let me know. I'd be more than happy to share info. Thanks in advance

New Member

Re: 3560 switchport amber/green alternating

I have had the same problem with a 2950T on one of the gig ports which was connected to a server.

sh int g0/1 showed me that the port has input/crc errors. I'm still running the switch but as far as I know I have to replace it.

Re: 3560 switchport amber/green alternating

looks like problem is with speed/duplex settings at both end. It's better to lock down speed/duplex setting at switch and router as well

New Member

Re: 3560 switchport amber/green alternating

They have been locked down from the start to 100/full. There is something else I'm missing

New Member

Re: 3560 switchport amber/green alternating

On this interface there has been only 13 input errors all being runts. The switch has been up for over 3 weeks and the errors are not increasing.

uptime is 3 weeks, 3 days, 2 hours, 52 minutes

Hall of Fame Super Bronze

Re: 3560 switchport amber/green alternating

If the errors aren't increasing and you don't have connectivity issues, I wouldn't be too concerned. I wonder if the light indicator has to do with the fact that you disabled mdix on the switch interface. I usually leave the mdix setting default, I wonder why you decided to turn it off.

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