#### LAB 1: Footprinting a target network using the ping utility ## Lab Objectives * Use ping * Find maximum frame size for the network * Identify ICMP type and code for echo request and echo reply packets ## Lab Environment Your Group machine: hostX.ws.nsrc.org (login via ssh) ## Lab Duration 10 Minutes ## Test Commands > ping -c 4 google.com #Analyze the stats # Find maximum frame size > ping hostX.ws.nsrc.org -M do -s 1500 sureronald@zion:~> ping hostX.ws.nsrc.org -M do -s 1499 PING hostX.ws.nsrc.org (10.10.0.8) 1499(1527) bytes of data. ping: local error: Message too long, mtu=1500 ping: local error: Message too long, mtu=1500 ping: local error: Message too long, mtu=1500 # You can see that the maximum packet size is less than 1500 bytes and more than 1300 bytes. Keep trying different values until you find the actual MTU frame size for this network #Now, find out what happens when TTL (Time to Live) expires. Every frame on the network has TTL defined. If TTL reaches 0, the router discards the packet. This mechanism prevents the loss of packets