Server Administration: Secure Network Design and Implementation

This report details the design and implementation of a secure server network for GAMMA Enterprise, a medium-sized UK company. The assignment involves subnetting a Class C private network address using VLSM into four subnets, configuring two virtual servers (Windows 2008/2012 and Ubuntu) with DNS, DHCP, web, email, and FTP services. The report includes detailed configurations, screenshots, and network diagrams. It covers testing the servers and implementing five security attacks using Kali Linux, along with suggested countermeasures. A cost analysis of the implemented solution is also provided. Additionally, the report explores network simulation using Riverbed Modeler and Packet Tracer to analyze network performance. The report concludes with detailed references.

Server Administration Design and Implementation
of a Secure Server Network
.
This ICA involves designing and implementing an Internet-connected secure server
network for a medium sized company named GAMMA Enterprise, UK. They want to
implement a secure network that uses Class C network address with four subnets –
server subnet and three LAN subnets and has approached you. They have asked you for
a price quote as well. But they want to see a virtual machine implementation and
simulation results before they commit to purchase anything.
You can use Virtual Machines as in the figure below for the implementation and the
security attacks. The server network should consist of two servers, i.e. Windows
2008/2012 and Linux (Ubuntu or others). They should each be connected to one
workstation each, i.e. Windows Server to Windows client and Linux Server to Linux
client and each of the workstation denotes a different LAN.
Write a report with the appropriate details (4500 words max, but flexible) documenting
all that you have done including how the servers are setup, how they are tested and
how the attacks are done to them along with countermeasures. Use the five tasks below
as a guideline to write.
Figure: Oracle VM Virtual Box Manager
Please do the following tasks:
1. Subnet a class C private network address with subnet mask /24 (you can choose
any) using VLSM (variable length subnet mask) into four subnets as follows: The

server network with a provision of 15 computers should be considered even
though we are using only two servers. Each of the LAN subnets should have 20,
40 and 60 computers respectively. Show the network address, first usable IP, last
usable IP and broadcast address for each subnet. (5 marks)
2. Using the Virtual Machines, configure the two physical servers namely Windows
2008/2012 and Ubuntu (or others), with the following: (1) DNS server (2) DHCP
server (3) Web server (4) Email server (5) FTP server. Using the client
computers each of these five servers should be tested to see that it works
properly. Capture the appropriate screen shots or illustrate that through
commands and output screens. Draw a simple network or workflow diagram of
your network, with the five different server implementations on each of the two
physical servers along with the two LANs, connected to the Internet. (20 marks)
HINTS:
• DNS Server: Show that the gammaenterprise.com (or similar) domain name is
configured and that the clients could join it. Configure it as a primary server,
possibly adding reverse look up zone and resource records. Create some users
and login into the domain. Test what was implemented.
• DHCP Server: Show the dynamic IP address assignment with an address pool
along with the evidence of clients receiving dynamic IP. NOTE: If the network
does not allow two DHCP servers at one time (which should be the case),
please disable one when you test.
• Web server: Configure IIS and Apache with
web address
www.gammaenterprise.com (or similar) can be accessed from the web clients.
Test the webserver with a sample webpage being accessed from clients.
• Email Server: Make sure you have an email client that could send and receive
emails through the SMTP server that is configured with email address like
user@ gammaenterprise.com (or similar).
• FTP Server: You can show how files could be uploaded and downloaded to and
from the FTP server using the FTP client tools or through command prompt.
3. Implement at least five security attacks on these servers through Kali Linux or
other independent tools and suggest countermeasures to stop them. Illustrate
the attacks through commands or using GUI tools. Capture the attacks through
screen shots. (10 marks)
4. You can try to implement the same network using the Riverbed Modeler
academic edition simulation tool and work on to get some output graphs on
traffic received, traffic sent, delay, packets dropped, etc. as the server and clients
communicate. See notes at the end (10 marks)

Figure: Riverbed Modeler Academic Edition
5. Show the detailed cost of implementing your solution, in a table format. You can
try to show two different costs for the company to choose from. HINTS: Research
on the costs of servers (hardware and software), switches, workstations, cables,
etc. (3 marks)
6. Show all references used in the report, using appropriate referencing. HINTS:
Harvard referencing can be used and make sure the format is fully followed. (2
marks)
NOTES ON RIVERBED MODELER AND PACKET TRACER:
(a) If you are using Riverbed Modeler Academic Edition (free software) there will be a
limitation of 80 total nodes in your network with less than 20 core nodes. If you have
more than that, the simulation will not produce results. So in that case I suggest the
following:
Create TWO scenarios.
• In the first scenario, design a LAN topology with all the necessary number of
nodes as in the ICA2, but don’t run the simulation, as it won’t run with so
many nodes. You can use the screen shots of your design from this scenario.

• In the second scenario (by duplicating first), design the LAN to have less
number of actual computer nodes and run the simulation of a
“representative LAN”. Or better use can use LAN model from Object Palette
and set the number the nodes to what you need (say 60 or 100 etc.; right
click and find the option through “Edit Attributes”). See the figure below.
You can get output graphs through this scenario and use it in the report.

NOTE: From the Riverbed official website: “Limited maximum number of total
nodes (80), Mobile nodes (20), Core nodes (20), and events (50 Million) in a
simulation run. (Note: Core nodes are wired devices connected to at least
two other devices in the network)”. Source: https://goo.gl/CcMFXB
(b) If you are using Packet Tracer and there will be no such limitations, but the graph
generation may not be as good as Riverbed Modeler – but there are other ways to
show that your design works through successful ping, showing delay values etc.
Packet Tracer is fine
END OF ASSIGNMENT