1 Reply Latest reply on Apr 4, 2012 7:50 AM by noor

    Interface errors on 1238

    smross New Member

      I have a port on a 1238 that is throwing alignment errors and CRC's.  In my experience this is usually a cable issue but i just wanted to make sure, that it could not be a possible duplex mismatch issue, everything is set to auto-negotiate. The device shows up in the MAC table, shows up on the 1335 ARP table but its not getting any connectivity and ping drops all packets but lets a few in every once in a while.  Is there a document for the 1238 or for AOS that describes interface errors? 


      Below is the output of some interface commands


      swx 0/13 is UP, line protocol is UP

        Hardware address is 00:A0:C8:60:DD:72

        100Mb/s, negotiated full-duplex, configured full-duplex

        output flow control is disabled, 0 pause frames sent

        input flow control is disabled, 0 pause frames received

        ARP type: ARPA; ARP timeout is 20 minutes

        Last clearing of counters 15:14:09

        5 minute input rate 32 bits/sec, 0 packets/sec

        5 minute output rate 872 bits/sec, 0 packets/sec

          917 packets input, 89781 bytes

          433 unicasts, 480 broadcasts, 4 multicasts input

          0 unknown protocol

          162 input errors, 0 runts, 0 giants

          5 alignment errors, 157 crc errors

          15182 packets output, 3186508 bytes

          2866 unicasts, 10395 broadcasts, 1921 multicasts output

          0 output errors, 0 deferred, 0 discards

          0 single, 0 multiple, 0 late collisions

          0 excessive collisions



      interface switchport 0/13

        spanning-tree bpdufilter enable

        spanning-tree bpduguard enable

        spanning-tree edgeport

        no shutdown

        switchport access vlan 50

        switchport voice vlan 51

        switchport port-security

        switchport port-security aging time 5

        switchport port-security maximum 2

        switchport port-security mac-address sticky

        switchport port-security mac-address sticky 00:1b:78:0c:41:c9 vlan 50





        • Re: Interface errors on 1238



          Thank you for your question. I would say I would agree with you regarding the errors you are seeing. Most of the time, it is either a bad cable or a duplex mismatch. However, since you have confirmed that the device connected to switchport 0/13 is also set to auto-negotiate, it would seem to rule a duplex mismatch out. One thing you may want to check is if the NetVanta 1238 and the device connected to switchport 0/13 are negotiating to the same speed and duplex. In this case, you would need to confirm if the device is negotiating to full-duplex with a speed of 100 Mbps.


          Another troubleshooting step, you could try is to move the device to another port on the NetVanta 1238 and see whether the issue follows. However, I do not see anything in your switchport configuration that could be causing the errors you are seeing.


          Below is a brief description of the ethernet interface errors you are seeing:


          Input Errors -  The number of data frames that were discarded on reception due to an error being detected in the data frame. This can include runts, giants, crc, and alignment errors.

          CRC Errors - The cyclic redundancy check (CRC) value did not match up with the data that was received and can indicate that one or more bits were received incorrectly. This can be caused by a noisy cable or a faulty connection.

          Alignment Errors - Caused by misaligned read and writes. For example, the AOS device could attempt a two byte read, but the memory address is not even a multiple of two. This could stem from the CRC errors where it appears that bits are being received incorrectly.


          Please do not hesitate to reply to this post if you have any further questions.