Good Night All,
This is a very good question. I will begin by defining the intrinsic behavior of a communication ports, how and why they are assigned and utilized within the connection-less communication infrastructure in an automated dynamically routed network.TCP is utilized when you require established communications versus UDP communications which do not require established relationships between nodes on a TCP/IP internet work.
The protocol ports are primarily deployed to build synchronized routing protocol databases between neighbor and nodes communicating across and in the internet work. It is analogous to having a trick or treat bag full of candy and consciously separating the chocolate krispies versus hard ginger candy. You chuck the latter treats!
Primarily, a port number is assigned to a dynamic routing protocol that enables a space in the hardware ASIC/RISC/Central Processing Unit memory space. Recursive routing table look-ups require 32Mbps of hardware memory. You can view these specific requests by typing the command:
Router1# show processes cpu
You will notice that the output shows IRQ requests alongside protocol numbers.
Ports provide a multiplexing service for multiple services
or multiple communication sessions at one network address.
In a computer, an interrupt request (or IRQ) is a hardware signal sent to the processor that temporarily stops a running program and allows a special program, an interrupt handler, to run instead.
The Internet Protocol (IP) is the principal communications
protocol in the Internet protocol suite for relaying
data grams across network boundaries. Its routing function
enables internet-working, and essentially establishes the
Internet.
The transport layer establishes basic data channels that
applications use for task-specific data exchange. The layer
establishes host-to-host connectivity, meaning it provides
end-to-end message transfer services that are independent
of the structure of user data and the logistics of
exchanging information for any particular specific purpose
and independent of the underlying network.
*-EIGRP is used on a router to share routes with other
routers within the same autonomous system. Unlike other
well known routing protocols, such as RIP, EIGRP only sends
incremental updates, reducing the workload on the router
and the amount of data that needs to be transmitted.
*-Border Gateway Protocol (BGP) is a standardized exterior
gateway protocol designed to exchange routing and
reachability information among autonomous systems (AS) on
the Internet.[1] The protocol is classified as a path
vector protocol.[2] The Border Gateway Protocol makes
routing decisions based on paths, network policies, or
rule-sets configured by a network administrator and is
involved in making core routing decisions.
BGP neighbors, called peers, are established by manual
configuration among routers to create a TCP session on port
A BGP speaker sends 19-byte keep-alive messages every
60 seconds[5] to maintain the connection.[6] Among routing
protocols, BGP is unique in using TCP as its transport
protocol.
Open Shortest Path First (OSPF) is a routing protocol for
Internet Protocol (IP) networks. It uses a link state
routing (LSR) algorithm and falls into the group of
interior gateway protocols (IGPs),
