IOS STATUS CODES

Line Status

  • Administratively down – means shutdown command was issued on an interface
  • down – means either: no cable;bad cable;wrong cable pinouts;speed mismatch;neighbor device is off;error disabled by port security

Protocol Status

  • up – Interface is working
  • down – either: shutdown command issued;cable issue;speed mismatch;neigbor is off;
  • down(err-disabled) – port security disabled status

Interface Status

  • disabled – shutdown command was issued
  • notconnect – bad cable;speed mismatch;;no neigbor device;
  • connected – interface is working
  • err-disabled – disabled by port security

Duplex

a-half – duplex was auto negotiated

INTERFACE CODES/COUNTERS

-Seen in “show interfaces fa0/0” command

-most of these counters are seen incremented during half duplex networking although late collisions point to a duplex mismatch

  • Input Errors – A total of many counters, including runts, giants, no buffer, CRC, frame, overrun, and ignored counts.
  • Runts – frames that didn’t meet the Frame size requirements of 64 bytes + 18 byte dest MAC,source MAC,and FCS. Can be caused by collisions
  • Giants – Frames that exceed the max frame size of 1518 bytes including the 18 byte dest/src MACs and FCS fields
  • CRC – frames that don’t pass the FCS algorithm, likely cause of collisions or interference
  • frame – frames received that have illegal formats. ie; partial bytes. Likely cause of collisions
  • Packets Output – Total number of Frames that are forwarded out an interface
  • Output Errors – total number of frames that the port tried transmitting but for some reason had an issue
  • collisions – counter of all the collisions that have occurred when the interface is transmitting a frame
  • late collisions – collisions that happen after the 64th byte has been transmitted. Very likely pointing to duplex mismatch and would increment on the switch using half duplex

VLAN CODES:

-from “show vlan brief” command

act/lshut —-means the vlan is shutdown