Networking: DHCP and NNTP Protocols

This document provides an analysis of address usage in networking, focusing on subnetting and IP address allocation. It also discusses the DHCP (Dynamic host Configuration Protocol) and NNTP (Network News Transfer protocol) protocols, including their description, purpose, transport layer protocols, transport layer ports, and how they work.

NETWORKING

Table of Contents
Part 1...........................................................................................................................................................2
Table 1.........................................................................................................................................................2
Table 2.........................................................................................................................................................2
Analysis of the address Usage.....................................................................................................................3
Part 3...........................................................................................................................................................3
DHCP (Dynamic host Configuration Protocol)..........................................................................................3
Description of the protocol.................................................................................................................3
Purpose of the protocol......................................................................................................................3
Transport layer protocols...................................................................................................................4
Transport layer ports..........................................................................................................................4
How it works.......................................................................................................................................4
NNTP application protocol (Network News Transfer protocol)...................................................................5
Description and Purpose.....................................................................................................................5
Transport layer ports..........................................................................................................................5
How it works.......................................................................................................................................6
References...................................................................................................................................................7
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Part 1
Table 1
Subnet Network address Mask donated Number of hosts
including pc
Number of
unused IP
address
A 192.168.128.0 255.255.192.0 256 32,766
B 192.160.0.0 255.240.0.0 254 1,048,574
C 192.168.128.0 255.255.224.0 254 8,190
D 192.168.136.0 255.255.248.0 254 2,046
E 192.168.140.0 255.255.254.0 254 510
Table 2
Device Interface IP address Mask dotted in
decimal
Default gateway
R1
Fa0/0 192.168.143.1 255.255.255.0 N/A
Fa0/1 192.168.140.1 255.255.255.0 N/A
S0/0 192.168.148.2 255.255.255.0 N/A
R2 Fa0/0 192.168.142.1 255.255.255.0 N/A
Fa0/1 192.168.140.2 255.255.255.0 N/A
S0/0 192.168.148.1 255.255.255.0 N/A
1st PC subnet A NIC 192.168.128.1 255.255.192.0. 192.168..0.1
Last pc subnet A NIC 192.168.255.254 255.255.192.0 192.168.0.1
1st PC subnet B NIC 192.160.0.1 255.240.0.0 192.160.0.1
Last pc subnet B NIC 192.175.255.254 255.240.0.0 192.160.0.1
1st PC subnet C NIC 192.168.128.1 255.255.224.0 192.168.128.1
Last pc subnet C NIC 192.168.128.254 255.255.224.0 192.168.128.1
1st PC subnet D NIC 192.168.136.1 255.255.248.0 192.168.136.1
1st PC subnet D NIC 192.168.136.254 255.255.248.0 192.168.138.1
DNS SERVER NIC 192.168.142.5 255.255.255.255 192.168.142.1
EAGLE SERVER NIC 192.168.142.8 255.255.255.255 168.168.142.1
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Analysis of the address Usage
The address were divided in different subnets using class A. Each was given its subnet IP
address of the lowest level according to the above tables. The IP address have been allocated in
the required manner to leave space for future growth.
Each subnet has been given a wide range of the IP address in order to allow more space for more
IP addresses. This means that many devices will be able to be connected to the network.
In order, leave more space for the IP address in the network different classes for allocating IP
address in the network should be used. This will make the network to have a wide range of IP
addresses in the network.
APPLICATION LAYER PROTOCOLS
Part 3
DHCP (Dynamic host Configuration Protocol)
Description of the protocol
Dynamic host Configuration Protocol is network supervision protocol that is utilize in assigning
IP addresses automatically to the end devices e.g computers, phones in a network to enable
communication among the devices in the network. The protocol automates and manages this
process of allocating the IP addresses to the devices a manually by the network administrators. It
can be used in both small networks and large enterprise networks that are found in large
companies. The protocol assigns different IP addresses when devices are moved from one place
to another without requiring any manually configuration [1]. This makes work easier for the
administrators where they do not require configuring IP addresses manually in the network.
DHCP protocol layer is available in two versions this includes version 4, which is used in
allocating the IP address to IP4, and version 6, which is used in allocating the IP addresses to
IP6.
Purpose of the protocol
Dynamic host Configuration protocol server sits around and wait for the client computers to
make request for IP addresses in the network. The server, which is normally defined with one or
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two parameters this can be the IP address range, subnet mask and DNS sever. The protocol has a
set of requests and responses, which creates the finite machine states in the network. When the
request comes in from the client, the router redirects them. The request, which has the MAC
address of the computer. The protocol then responses to the client requests with the IP address
and the subnet mask address and other parameters if available in the network. The client is only
allocated with the IP addresses are within the defined scope in the DHCP server. This dialog
communication between the client and the server manages IP allocation; hence, the devices
connect to the network.
Transport layer protocols
UDP protocols are used for communication.
Transport layer ports
The protocol works with the connectionless service model that utilizes User Datagram Protocol
(UDP). The layer is implemented with two UDP port numbers for its operations, which are
normally alike just has the bootstrap protocol. The UDP port number is normal 67, which is the
terminal port of the server and the UDP port number 68, which is used by the client. This two
ports makes the process pf data exchange between the server and client to be efficient and on
time so that, client devices can connect to the network automatically thus communicating
between each other for IP allocation.
How it works
DHCP runs at the application layer of the TCP, which dynamically allocates IP addresses to
clients and other protocol stacks. This protocol stacks include subnet mask default getaway and
DNS addresses. When a device is connected to a network, the DHCP-enabled client sends a dhcp
discover message to the DHCP server to connect to the network and identify the server. The
clients request for the network configurations for the local network in which they are connected.
The query is immediately broadcasted and DHCP request message send to the server
immediately the client device boots up. The DHCP server then responds back to the request
message by proving the IP configuration parameters that were configured in the DHCP server.
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This are the IP addresses and the time of allocation, that can be called lease. When the device is
refreshed, again the same information is demanded from the server.
The DHCP server keeps record of all the IP addresses that it allocates to devices in the network.
If a device is moved from one location to another then server identifies it and allocates it with IP
address using its MAC address. This prevents multiple devices from being allocated with the
same IP address within any given network.
Contingent upon the associations between these focuses and the quantity of clients in every area,
different DHCP servers can be set up to deal with the appropriation of addresses. In the event
that organize directors need a DHCP server to give tending to numerous subnets on a given
system, they should design DHCP transfer administrations situated on interconnecting switches
that DHCP demands need to cross. These operators hand-off messages between DHCP
customers and servers situated on various subnets.
NNTP application protocol (Network News Transfer
protocol)
Description and Purpose
The Network News Transfer protocol is a protocol that is found in the application layer, is used
in transporting Usenet news Articles from the news server and posts it to the client’s applications
side for reading. It was designed basing on UCCP network, where most of article transfers takes
place through point- point network telephone links between the news server and the client
applications. Readers can log to this computers and red news directly from the local disk. It
resembles the SMTP but it is mainly used in exchanging news articles in the network. NNTP
protocol is used by a software named newsreader to read news directly from on Usenet from the
new server. Furthermore, we say that NNTP enables server/client communication. This means
that they can communicate with each other and duplicate the news group among each other this
creates the Usenet .When dealing with client-server model, NNTP protocols enables clients to
connect to the server and read the news through providing commands in the browsers.
Transport layer ports
The TCP port 119 is normal put aside for NNTP communication .On the other side TCP port 433
(NNSP) is used in the bulk transferring of the news article from one server to another. This is
called NNTPS. In addition, port 119 can be changed to use TLS through STATTLS command.
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These ports enable communication between news server and the client applications on the other
side.
How it works
Newsgroup begin with only one news server then duplicated into a thousand of other
servers .This means that each news server has a special software that maintains files for each
group within any given network the following describes how the news server work.
Using NNTP newsreader application associates to the news server that is selected in the
configurations. Naturally, the internet service provider provides connection to the news server,
data. Once the connection is successful, the software downloads all the news, which have been
subscribed to. Then a message is send to the server form the newsreader software. If the software
is offline, it reconnects to the server, using NNTP. Then the news server saves the messages in
the file for the newsgroup [2]. Newsgroup files are usually large in size hence messages are
appended at the end of the files. Then the news server connects to one or more news servers
using NNTP and updates data. Each server in the network compares the information between
them and adds any difference that is found between them. Since each server has information that
previously had, it would lose any messages presented on it amid the refresh. By looking at the
documents, it can separate the new messages and add them to the record it has, without losing
any new postings. The news server at that point sends the consolidated record to alternate news
servers.
The newsgroup changes are duplicate to each available server until all the information are
updated. This process of updating information is virtually continuous. Due to this, all subscribers
read the information that is posted and can reply on them. The new replies can viewed, this
process goes on repetitively.
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References
[1] Schulzrinne, H.. Dynamic host configuration protocol (DHCP-for-IPv4) option for session
initiation protocol (SIP) servers, 2012, (No. RFC 3361).
[2] Visoottiviseth, V., Mogami, T., Demizu, N., Kadobayashi, Y. and Yamaguchi, S. M/tcp: The
multicast-extension to transmission control protocol. In Proceedings of ICACT, February, 2011.
.
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