How Do I generate a large number of input errors or crc errors on a cisco router ethernet interface ios 12.4
Posted on 2009-12-17
I'm evaluating software that calculates interface error %
I'd like to prove that it's working correctly by generating a large number of input errors on the ethernet interface.
I have tried using nmap scans with the --bad crc flag but the cisco router doesn't consider these packets to be input errors.
i have also tried building packets by hand with bad checksums and I have send giant packets but it appear that giant is not considered an input error
the router interface is directly connected to a windows pc by crossover cable.
I have changed the link speed and duplex settings between the pc and router interface, this causes occasional input errors but not enough. I'm trying to drive input errors up near 100%
I run the command
show interface fastethernet 0/0 and get
199239 packets input, 54063855 bytes
Received 2744 broadcasts, 0 runts, 83 giants, 0 throttles
4555 input errors, 0 CRC, 0 frame, 0 overrun, 4555 ignored
I'd like to push the number of input errors close to the number of total packets