Monday, October 10, 2011

Running a ping test on linux machines

A couple of things are required:
  1. Only kernels newer than 1.X something work. So if you have 2.x or greater you are fine.
  2. You need to enable this flag is disabled:  
    echo "0" > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts
     Ping 224.0.0.1 ==> All machines supporting multicast are supposed to respond to that request.

TCPDump shows lot of SSH packets

The effect of positive feedback:

New packet --> screen refresh --> more ssh display packets back and forth ---> this causes more screen refresh --> infinite loop until you stop it.