Internet Protocol (IP)
August 16, 1999
Internet Protocol (IP) is a connectionless protocol that
gateways use to identify networks and paths to networks
and hosts. In other words, IP handles the routing of data
between networks and nodes on those networks.
You will be familiar with IP because in order to address web
pages, you must use domain names like www.barclayscapital.com,
or their numerical counterparts called IP addresses.
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NOTE: Domain names are far easier to remember
than IP addresses so we usually use domain names instead of
IP addresses and rely upon Domain Name Servers to tie
domain names to their IP address counterparts behind the
scenes.
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IP addresses are unique sets of four period delimited
octets that represent individual hosts on specific networks.
A TCP/IP octet is a number between 0 and 255. Thus, an IP
Address might look something like:
30.85.1.26
which you might read as something like
"computer named 26, on
network 1, on host 85, of network 30."
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NOTE: 255 is usually a reserved number which means broadcast
to all hosts and 0 represents "this", or the current host.
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Besides defining the address scheme, IP also handles the
transmission of data from an originating computer to the
computer specified by the IP address. It does so by breaking
up large, unwieldy chunks of data into easily
manageable IP packets that it can deliver across the network.
That is why we talk of IP being a connectionless protocol.
In an effort to better manage network traffic, IP specifies
the protocol for breaking single messages into a slew of
portions. Each portion is responsible for finding its way
across the network based on changing traffic
congestion and the IP protocol.
Each time a message arrives at an IP router, the router
decides where to send it next. There is no concept of a
session with a preselected path for all traffic. Routers can
send data along the path of least resistance regardless of
local network traffic congestion.
If one phone line on the network breaks down, for example,
traffic can still reach its destination through a
roundabout path.
The Basics of TCP/IP
Introduction to the Web Application Development Environment (Tools)
Transmission Control Protocol (TCP)
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