Operation of Ping

Presented by:Jubayer Al Mahmud

Table of Contents What is ping? Origin of the name How ping works? Successful ping test Unsuccessful ping test Error indications Packet Loss Packet Latency Traceroute vs Ping Ping in Online Video Games What affects ping? Benefits Drawbacks Ping of Death

What is Ping?

A computer network utility to determine whether a specific IP address is accessible

Measures the round-trip time for messages sent from the originating host to a destination computer and back

Origin of the name

PING: Packet Internet Groper

Originated from active sonar terminology that sends a pulse of sound and listens for the echo to detect objects underwater

Written by Mike Muuss in December, 1983

How ping works?

Operates by sending ICMP echo request (ping) packets to the target host and waiting for an ICMP echo reply (pong)

It measures the round-trip time from transmission to reception, reporting errors and packet loss

Successful Ping test

Shows a statistical summary of the response packets received

Also includes minimum, maximum and mean RTT

Successful Ping test

Successful Ping test

No guarantee!!!

The real request might not pass through

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 specific problem, ping notification includes error notification indicating that problem

Unsuccessful Ping test

Unsuccessful Ping test

No guarantee!!!

The real request might pass through

Error indications

H, !N or !P – host, network or protocol unreachable S – source route failed F – fragmentation needed U or !W – destination network/host unknown I – source host is isolated A – communication with destination network

administratively prohibited

Error indications

Z – communication with destination host administratively prohibited

Q – for this ToS the destination network is unreachable

T – for this ToS the destination host is unreachable X – communication administratively prohibited V – host precedence violation C – precedence cutoff in effect

Packet Loss Packet loss occurs when one or more packets of data

travelling across a computer network fail to reach their destination

Packet loss can be caused by a number of factors:• Signal degradation over the network medium due to multi-

path fading• Packet drop because of channel congestion• corrupted packets rejected in-transit• faulty networking hardware

Packet Latency Contributes to network speed Refers to any of several kinds of delays typically

incurred in processing of network data It is the Round Trip Time showed in Ping operation Measured in milliseconds (ms) On DSL or cable Internet connections, latencies of less

than 100 ms are typical and less than 25 ms desired. Satellite Internet connections have average 500 ms or

higher latency.

Traceroute vs Ping

Traceroute is a utility that traces a packet from a computer to an Internet host

It shows how many hops the packet requires to reach the host and how long each hop takes

Traceroute vs Ping

Ping will determine the reachability of a host on an IP network

Ping will also test the speed of a connection to the server

Traceroute determines how long a packet (32 bytes in size) takes to go from a computer to the host and back to the computer again

Ping in Online Video Games

Network latency between a player’s computer (client) and either the game server or another client

Instead of using traditional ICMP packets, programmers often build their own latency detection into existing game packets

Low ping provides smoother gameplay by allowing faster updates of game data.

What affects ping ? Depends on distance and internet traffic at that time

Connection may have to be routed through 15 or 20 hops (different locations) to reach the destination server

Try to chose a closer server for lower latency

What affects ping ? Congested/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 network usage should be halted

Benefits

Determines the status of the network

Troubleshoots networks

Determines response time of a destined IP address

Determines network latency

Drawbacks

Adds load to the system, causing problem with routers across the internet

Ping Flood (DoS attack), victim is overwhelmed with ICMP echo requests.

Ping of death

Ping of Death A type of Denial of Service (DoS) attack

Such an attack in 1996 involved sending IP packets of a size greater than 65,535 bytes to the target computer

IP 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 rebooted

Ping of Death By the end of 1997, operating system vendors had

made patches available to avoid the ping of death

Thank You