I have a strange problem that started at 3am last night. I have a device that is connected to a 3560G, and it suddenly stopped communicating with the switch. If I try and move it to any other port it will not work. If I reset this device to factory default, and re configure it, with a different ip address, etc, it will still not communicate with the switch.
If I move this device to another switch, router or laptop, it has no problems communicating with them. With that I have determined that the 3560G is at fault.
I am not able to reload the switch at this time, so I am wondering if there is something I need to try and clear from the switch. At this point I can see the mac address table for the device on the correct port, but I cannot ping it.
Is there anything I can do to troubleshoot this other than clearing the arp and the mac address table for that port?
I have a strange problem that started at 3am last night. I have a device that is connected to a 3560G, and it suddenly stopped communicating with the switch. If I try and move it to any other port it will not work. If I reset this device to factory default, and re configure it, with a different ip address, etc, it will still not communicate with the switch. If I move this device to another switch, router or laptop, it has no problems communicating with them. With that I have determined that the 3560G is at fault.
Question: Is this device running on 1 Gbps line speed on the 3560CG and when you moved it to another switch, router or laptop did it negotiate to just 100 Mbps?
If you connect a notebook to this switch port is it communicating with different speeds? ( speed, duplex, auto)?
Remote possibility, do you feel there is duplicate IP conflicting with this device. Is the interface clean - error, CRC reliability etc
I faced similar problem in the past resolved after the physical cabling was replaced by new CAT 6E..
Not sure if you have cable check or similar command on the switch.
Hope this helps..
Yes, if I connect a notebook the port works fine. No chance of a duplicate IP, as I had this device and nothing else connected.
There are no errors on the port either:
GigabitEthernet0/46 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 0023.051f.e12e (bia 0023.051f.e12e)
MTU 1500 bytes, BW 100000 Kbit/sec, 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, 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 00:00:16, 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: 32807
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
1092041447 packets input, 2115068914 bytes, 0 no buffer
Received 14832670 broadcasts (7179158 multicasts)
5 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 7179158 multicast, 0 pause input
0 input packets with dribble condition detected
1303344359 packets output, 3606277833 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 unknown protocol drops
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
Cable tests good too:
TDR test last run on: May 14 09:27:06
Interface Speed Local pair Pair length Remote pair Pair status
--------- ----- ---------- ------------------ ----------- --------------------
Pair A 94 +/- 4 meters Pair B Normal
Pair B 87 +/- 4 meters Pair A Normal
Pair C 1 +/- 4 meters Pair C Open
Pair D 1 +/- 4 meters Pair D Open
Cable tests good too
No it's not. This is why I asked the initial question.
Pair D 1 +/- 4 meters Pair D Open
The behaviour with your device is NORMAL. Why? Look at the result of Pair "D". Pair "D" controls GigabitEthernet and the test results shows OPEN circuit and an open circuit means BAD. This is why if you plug this to a Cisco GigabitEthernet switch port the link goes down. But if you plug this to FastEthernet switch port the link goes up.
The cable distance shows the cable directly connected to the switch port is faulty and needs to be replaced. Another thing, the distance is close to maximum limit of FastEthernet/GigabitEthernet of 100 metres.
If you are unable to replace the cable and you need to connect this to the 3560CG then the only way force this link to go up is to set the speed of the port down to 100 Mbps using the interface command "speed auto 10 100".
Read more about TDR HERE.
Hope this helps.
I guess I failed to specify that this is connected to a 100Mbit device. Not a Gigabit device. So yes the cable tests good.
And I get a link at 100Mbps, getting the link is not the problem. It won't communicate with the device over the link. Things like CDP and mac address table work, but there is no tcp communication.
I had tried the speed 100, duplex full commands, didn't make a difference. But again, I had a link all along.
Ok, take this device off the network and replace it with something. See if you can see the same behaviour. I am suspicious about your device. Looking at the "sh interface" output, I can see regular input/output. If there was something wrong with the link, you won't see any traffic or you'll only see one-way traffic (from the switch down to the device).
Also, can you confirm this link is almost 100 metres long?
Looks like points are coming inline now.
As you said notebook connected to this port works fine, this back's up the point that switch port may be good.
Cable is almost reaching 100 meters max allowed distance in theory.
Pair of cables C,D is showing open. Not sure why one pair length is 94 meter and other pair is 87.
One thing you can try is, if you have access to switch closet, try directly connecting this device to switch with a good quality new patch chord. This will eliminate all other variables on the table.
Yes the cable is around 100 meters. The notebook works fine when connecting to the port and when connecting to the device with the same patch cord. A new patch cord didn't make any difference either.
I am going to start replacing stuff today. See how that goes.....eventually it will work once everything is replaced....
Is it possible to use Wireshark on this device and see what it is seeing from the switch? Or alternatively can you monitor session and see what is being sent and received on that port?