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fastethernet port comes up and then goes down lost carrier

bob bob
Level 1
Level 1

I have a Cisco 881 which is to be connected to a vendors switch (also Cisco) every time I enable the interface the port comes up up then transitions to down down and the indication light on the 881 stays amber. My thought is that they have port security enabled on their end but I haven't gotten a clear answer from them.

here is the interface configuration

!

interface FastEthernet3

 switchport access vlan 99
 no ip address
 no cdp enable
end

 

 

sh logging..

007323: Jun 30 13:23:29.479: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to up
007324: Jun 30 13:23:30.479: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet3, changed state to up
007325: Jun 30 13:23:32.199: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet3, changed state to down
007326: Jun 30 13:23:33.203: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to down

I have had our guy on site try a different patch cable between the 2 devices and different ports but it does the same thing. 

sh int

FastEthernet3 is down, line protocol is down 
  Hardware is Fast Ethernet, address is 64e9.5019.4311 (bia 64e9.5019.4311)
  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)
  Auto-duplex, Auto-speed
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:18, output never, output hang never
  Last clearing of "show interface" counters 00:45:06
  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
     194 packets input, 21122 bytes, 0 no buffer
     Received 46 broadcasts (136 multicasts)
     0 runts, 0 giants, 0 throttles 
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     67 packets output, 12263 bytes, 0 underruns
     0 output errors, 0 collisions, 3 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     42 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

Any help would be appreciated. I'm not sure if there is a debug that would help here. 

6 Replies 6

Reza Sharifi
Hall of Fame
Hall of Fame

Is this a copper port?

Some providers set their side at full duplex.  So, you may want to try to set the port to 100Mb full duplex on your side and test again.

HTH

 

Thanks for your reply,

Yes copper. I tired setting the interface to 100 full, still having the problem.

Hello

What mode does this port need to be in? -  routed or switched?


res

Paul


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

Hi Paul,

It would be a switchport. 

 

here is what the vendor sent me as far as their end

interface GigabitEthernet0/1
 description CUST ROUTER
 switchport access vlan 9
 switchport mode access
end

The vlans are different, but that shouldn't be a problem, I think it would just trigger a VLAN mismatch.

Hello

Are these two devices physical connected to each other ?

So your 881 router is connecting a cisco vendors switch via what port?

Do you have  SVI interface of the this router enabled - something like this?

int vlan 1
no shut

interface FastEthernet3
no switchport access vlan 99

res

Paul

 


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

bob bob
Level 1
Level 1

Another thing I noticed is the interface comes up and goes back up about once a minute

007395: Jun 30 13:58:44.488: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to up
007396: Jun 30 13:58:46.536: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to down
007397: Jun 30 13:59:50.258: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to up
007398: Jun 30 13:59:52.302: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to down
007399: Jun 30 14:00:56.364: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to up
007400: Jun 30 14:00:58.408: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to down
007401: Jun 30 14:02:01.798: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to up
007402: Jun 30 14:02:03.850: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to down
007403: Jun 30 14:03:07.592: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to up
007404: Jun 30 14:03:09.636: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to down
007405: Jun 30 14:04:13.674: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to up
007406: Jun 30 14:04:15.718: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to down
007407: Jun 30 14:05:19.776: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to up
007408: Jun 30 14:05:21.824: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to down
007409: Jun 30 14:05:33.928: %SYS-5-CONFIG_I: Configured from console by access on vty0 (10.1.20.77)
007410: Jun 30 14:06:25.209: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to up
007411: Jun 30 14:06:27.258: %LINK-3-UPDOWN: Interface FastEthernet3, changed state to down

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