Ping is a network utility that checks the reachability of an IP address and measures round trip time for messages. It operates by sending ICMP echo requests and can indicate errors, packet loss, and latency issues. The 'ping of death' is a historical denial of service attack involving oversized ICMP packets that could cause system crashes, prompting vendors to issue patches.
WHAT IS PING?
•PING (Packet Internet Groper) is a software utility used to determine
whether a given IP address is accessible or not.
• It measures the round trip time for messages sent from the
originating host to a destination computer/device that are echoed back
to the source.
• The program was written by Mr. Mike Muss in December,1983.
• The name originated from active SONAR terminology that sends a
pulse sound and listens for the echo to detect objects underwater.
3.
HOW DOES PINGCOMMAND WORK?
• A PING command usually sends a signal to another device one is trying to reach and
see if you get a response.
• PING operates by sending an ICMP(Internet Control Message Protocol) echo
request to a network address at periodic intervals waiting for an echo ICMP
response.
• It also measures the time it takes for an echo response to arrive.
• The request sent using ICMP is nothing but a packet of data .
• Latency : It refers to the time elapsed between transmission of request and receiving
the accurate reply from the target host.
• It also indicates errors and packet losses .
UNSUCCESSFUL PING TEST
•In cases of no response from the target host ,most implementations of ping print
notifications about timing out periodically.
• In case of a specific problem , ping notification includes error notification indicating
that problem.
6.
ERROR INDICATIONS
• H,!N or !P = Host or network or protocol is unreachable.
• S = Source route failed.
• F = Fragmentation needed.
• U or !W = Destination network or Host unknown.
• I = Source host isolated.
• A = Communication with destination network administratively
prohibited.
• Q = For this ToS the destination network is unreachable.
• V = Host precedence violation.
7.
PACKET LOSS
• Packetloss occurs when one or more packets of data travelling across the
computer network fail to reach their destination.
• Packet loss can be caused by the following factors:-
• Signal degradation over the network medium due to multipath failing.
• Packet drop because of channel congestion.
• Corrupted packets rejected in transit .
• Faulty networking hardware.
8.
PACKET LATENCY
• Itcontributes to the network speed.
• Refers to any several kind of delays typically occurring in processing
of data.
• It is measured in milliseconds (ms).
• On DSL or cable internet connections, latencies of less than100 ms are
typical and less than 25 ms are desired.
• Satellite internet connections have avg . 500 ms or more latency.
9.
WHAT AFFECTS PING?
•Distance of target host and internet traffic at that time.
• Congested or overloaded routers on the way to the target machine.
• Excessive network utilization(downloading) can result in increased
latency due to the fact that the packets experience queuing delay.
• To ensure low latency , all other unnecessary networks should be
halted.
10.
PING OF DEATH!!!!
•It is a type of DoS (Denial of Service) attack.
• Such an attack in 1996 involved sending ICMP packets of size greater than
65,535 bytes to target computer.
• The ICMP packets of this size are illegal, but applications can be built that
are capable of creating them.
• Operating systems not programmed to handle such a situation Froze,
Crashed or Reeboted.
• By the end of 1997 operating system vendors had made patches available to
avoid ping of death.