Hi every body.
I just want to know when we use the command " show int " on a cisco switch, it will show different counters such as input error ,output error, etc.
What are input error and output error?
what is considered as input and output?
thanks and have a nice weekend.
This command is not applicable to the 2900/3500XL, 4XXX and 6XXX. Try the command "sh controller ethernet " for a refine output.
There are a number things that can cause input and output errors. Example:
By default, all layer 2 ports are in dynamic desirablemode, so the layer 2 port tries to form a trunk link and sends out DTP packets to the remote device. When a layer 3 interface is connected to a layer 2 switchport, it is not able to interpret these frames, which results in Input errors, WrongEncap errors, and Input queue drops.
Have a look at this document for more info:
input packets = valid packets received on the interface
output packets = valid packets transmitted successfully on the interface
input errors are errors in receiving packets, specific error types apply to different interface type (serial, ATM, fastethernet)
output errors are errors in sending packets out the interface.
for ethernet interfaces you can look at:
see the description of all fields here:
among input errors there are:
giants : frames too big to be received
runts: frames too short (minimum size is 64 bytes in ethernet)
CRC : FCS checksum fails
possible output errors include collisions, late collisions, multiple collisions
Hope to help