Late Collision on WAN Link Interface

[Mohammed Yaseen Ansari]

Hi All,

I have been facing on one of my Router WAN MPLS Link Connected Interface, FE. In logs, I am getting below logs continuously and have done below troubleshooting.

1. Router Model - Cisco 1841, IOS (C1841-ADVIPSERVICESK9-M), Version 12.4(19b).
2. Interface Fa0/1 - connected to MPLS Link, Its going ISP. On this interface I am getting logs and its Interface is configured Speed/Duplex Auto but its auto-negotiating to Half/100Mbps. At the other end (ISP), its confirmed that they have configured Full/100Mbps.
3. We tried changing the settings but each time we lost the connectivity to the router after that change and had to revert to auto settings.
4. Checked cable type. It was Straight-Through and changed the same to Cross-Over.
5. Cable is of good quality and its Cat 6A. Length 3m only.
6. Device CPU utilization is being fine.

Please let me know:

1. What could be the possible reason for this and how can I resolve it?
2. What would be the impact on router and the traffic flow? So far I haven't received any issues and ping response for this link seems normal (as what is expected).

Apr  3 14:42:38 CEST: %GT96K_FE-5-LATECOLL: Late Collision on int  FastEthernet0/1
Apr  3 14:42:40 CEST: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
Apr  3 14:42:46 CEST: %GT96K_FE-5-LATECOLL: Late Collision on int  FastEthernet0/1
Apr  3 14:42:46 CEST: %GT96K_FE-5-LATECOLL: Late Collision on int  FastEthernet0/1
Apr  3 14:42:48 CEST: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
Apr  3 14:43:11 CEST: %GT96K_FE-5-LATECOLL: Late Collision on int  FastEthernet0/1
Apr  3 14:43:13 CEST: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
Apr  3 14:43:42 CEST: %GT96K_FE-5-LATECOLL: Late Collision on int  FastEthernet0/1
Apr  3 14:43:44 CEST: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up

RTR01#sh int f0/1
FastEthernet0/1 is up, line protocol is up
  Hardware is Gt96k FE, address is 001c.5846.e8a5 (bia 001c.5846.e8a5)
  Description: **MPLS link connected to AUROHYD_RTR 192.168.83.2**
  Internet address is 192.168.83.42/30
  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)
  Half-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: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 8000 bits/sec, 5 packets/sec
  5 minute output rate 9000 bits/sec, 4 packets/sec
     12648229 packets input, 2616311911 bytes
     Received 2 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
     10879116 packets output, 1842349659 bytes, 0 underruns
     5308 output errors, 19560 collisions, 5296 interface resets
     0 unknown protocol drops
     0 babbles, 5333 late collision, 0 deferred
     0 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out

RTR01#sh run int f0/1
Building configuration...

Current configuration : 165 bytes
!
interface FastEthernet0/1
 description **MPLS link connected to ISP**
 ip address 192.168.83.42 255.255.255.252
 duplex auto
 speed auto
end

Can anybody help me out and share your details thoughts on this, please. Thanks!

Regards,

Yaseen