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mahesh18
Frequent Contributor

lost carrier error and interface went up and down

Hi all,

I have 2650 XM Router connected to Cable modem.

It has input errors.

i changed cable also still same thing.errors do not stop.

sh  int fa0/0
FastEthernet0/0 is up, line protocol is up
  Hardware is AmdFE, address is 000f.8f6d.7e60 (bia 000f.8f6d.7e60)
  Internet address is
  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, 100BaseTX/FX
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:00, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/2/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 14000 bits/sec, 30 packets/sec
  5 minute output rate 1000 bits/sec, 1 packets/sec
     111292 packets input, 6907618 bytes
     Received 109236 broadcasts, 0 runts, 0 giants, 0 throttles
     4077 input errors, 0 CRC, 0 frame, 0 overrun, 4077 ignored
     0 watchdog
     0 input packets with dribble condition detected
     2058 packets output, 184333 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out

any idea how can i get rid of these errors

thanks

mahesh

Message was edited by: mahesh18

14 REPLIES 14

Hi Mahesh,

4077 packets have been 'ignored' by the interface because the interface  hardware ran low on internal buffers.

Input Error includes runts, giants, no buffer, CRC, frame, overrun, and ignored counts. Other input-related errors can also cause the input errors count to be increased, and some datagrams can have more than one error. Therefore, this sum cannot balance with the sum of enumerated input error counts.

Just try shut and no shut the port and hard code the duplex/speed setting at both ends of router and modem.

HTH

Regards

Ganesh.H

Hi,

How can i hardcode on cable modem?

also when i hard code on router interface then crc errors  got started.

thanks

mahesh

Hi Mahesh,

Ok then try with auto what negotition it takes just check if it takes 10 Mbps and full duplex then in modem you need to configure full duplex with 100 Mbps setting.

HTH

Regards

Ganesh.H

Hi,

fa0/0  is already config  with auto auto

duplex auto
speed auto

thanks

mahesh

Hi Mahesh,

If your switch supports TDR, use the "test cable-diagnostics tdr" command.

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/50sg/command/reference/snmp_vtp.html#wp1208382

and check out the below link on ethernet collision troubleshooting hope this helps out your query!!

http://www.cisco.com/en/US/products/hw/modules/ps2033/products_tech_note09186a008009446d.shtml

Regards

Ganesh.H

Hi Ganesh,

problem is with wan interface of router that connects to cable modem

no switch involved

int fa0/0  goes to ISP  cable modem

thanks

mahesh

here it is what i did from router

#test int fastEthernet 0/0
U.U Failed - timeout problem
1 interfaces: 0 passed, 1 failed, 0 skipped, 0 untestable

Hi Mahesh,

Use the 'clear counters' command to reset the counters and monitor the interface parameters over time (less than 24 hours).
Monitor the ignored packets over time. If they are increasing, paste the output from the 'show buffers' command to see if   the buffers can be tuned. Also, compare with the 'no buffer' counter and input/output queue drops. Broadcast storms can cause the 'ignored' counter to increment.

HTH

Regards

Ganesh.H

hi ganesh

i will follow ur recommendations

thanks

mahesh

glen.grant
Advisor

   Most cable modems only know auto for speed/duplex , make sure the router speed/duplex is also set as auto for speed/duplex . Clear counters then see if that helps.

mahesh18
Frequent Contributor

hi glen

thanks for reply.

my router int is set to aut auto.


duplex auto
speed auto

i have cleared the counters and i am monitoring it now.

is there anything i can check ?

thanks

mahesh

mahesh18
Frequent Contributor

Hi all,

now the interface fa0/0 flapped few times  theni saw lost carrier  error on the interface.

then i replaced the lan cable.

since then no errors

  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, 100BaseTX/FX
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:00, output hang never
  Last clearing of "show interface" counters 1d13h
  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 11000 bits/sec, 22 packets/sec
  5 minute output rate 1000 bits/sec, 1 packets/sec
     3456425 packets input, 1634130700 bytes
     Received 2344447 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog
     0 input packets with dribble condition detected
     790814 packets output, 90767572 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out

i am monitoring it now

mahesh18
Frequent Contributor

Hi all,

i check the interface after i replace the cable now it shows   38 lost carrier  ***********************

Internet address is 96.51.139.43/22
  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, 100BaseTX/FX
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:00, output hang never
  Last clearing of "show interface" counters 1d21h
  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 13000 bits/sec, 22 packets/sec
  5 minute output rate 1000 bits/sec, 1 packets/sec
     4012393 packets input, 1669567741 bytes
     Received 2899454 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog
     0 input packets with dribble condition detected
     795364 packets output, 91329142 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     38 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out

Any ideas what i can do next?

thanks

mahesh18
Frequent Contributor

Also i check my router 2650xm logs and found that

Jan  7 14:15:15.789 MST: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to down
Jan  7 14:15:20.261 MST: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up

2650XM#                          sh int desc
Interface                      Status         Protocol Description
Fa0/0                          up             up       WAN Connection to ISP modem