College of the management, economics and information technology Department of Information systems

Fall Semester, academic Year 2015/2016 Lab 05: DNS Server/ E-mail Server

IntroductionThe Domain Name System (DNS) is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities. Most prominently, it translates domain names, which can be easily memorized by humans, to the numerical IP addresses needed for the purpose of computer services and devices worldwide. The Domain Name System is an essential component of the functionality of most Internet services because it is the Internet's primary directory service.

The Domain Name System distributes the responsibility of assigning domain names and mapping those names to IP addresses by designating authoritative name servers for each domain. Authoritative name servers are assigned to be responsible for their supported domains, and may delegate authority over sub-domains to other name servers. This mechanism provides distributed and fault tolerant service and was designed to avoid the need for a single central database.

The Domain Name System also specifies the technical functionality of the database service which is at its core. It defines the DNS protocol, a detailed specification of the data structures and data communication exchanges used in DNS, as part of the Internet Protocol Suite. Historically, other directory services preceding DNS were not scalable to large or global directories as they were originally based on text files, prominently the HOSTS.TXT resolver. DNS has been in wide use since the 1980s.

The Internet maintains two principal namespaces, the domain name hierarchy[1] and the Internet Protocol (IP) address spaces.[2] The Domain Name System maintains the domain name hierarchy and provides translation services between it and the address spaces. Internet name servers and a communication protocol implement the Domain Name System.[3] A DNS name server is a server that stores the DNS records for a domain name; a DNS name server responds with answers to queries against its database.

The most common types of records stored in the DNS database are for DNS zone authority (SOA), IP addresses (A and AAAA), SMTP mail exchangers (MX), name servers (NS), pointers for reverse DNS lookups (PTR), and domain name aliases (CNAME). Although not intended to be a general purpose database, DNS can store records for other types of data for either automatic machine lookups, such as DNSSEC records, or for human queries such as responsible person (RP) records. As a general purpose database, DNS has also seen use in

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combating unsolicited email (spam) by using a real-time black hole list stored in the DNS. Whether for Internet naming or for general purpose uses, the DNS database is traditionally stored in a structured zone file.

Recommended Equipment

Packet Tracer

Section 01: DNS Server

Learning Objectives

Connect a PC to a server.

Configure a server to be a DNS server.

Configure a PC to be a client to a DNS server and then obtain an IP address from the

DHCP server

Introduction The Domain Name System (DNS) is provide the service to convert any URL (web address)

from its name to an IP address to allow getting websites by hosts easily.

Example:www.yahoo.com converted to 172.18.0.2 as an example.

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Task 1: Setup and test a network

Step 1. Set up the network topologyA. Add two pcs to the work area.

B. Add DHCP and DNS servers to the work area.

C. Connect as shown in the figure above

Step 2. Observe the default DNS settings.

A. Click the Server. The server configuration window opens,

B. Click the Config tab. The Global Settings appear. Change the display name to DNS

Server.

C. Click the Interface button on the left then click on FastEthernet. Set the following static

IP address to 172.18.0.2 and Subnet mask to: 255.255.255.0. for the DHCP server set

the following IP 172.18.0.1

D. Click the services button on the left then click on DNS and set the following settings:

DNS Service: on

Name : www.yahoo.com Address: 172.18.0.2

E. Click on Add then save

Step 3. Configure DNS on the client workstations.

Click the PC in the logical workspace. Click the Desktop tab and click the IP Configuration button and then choose DHCP.

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Step 4. Test the Network

Click the PC in the logical workspace. Click the Desktop tab and click the Web Prowser button and then make a test:

1. Write 172.18.0.2 as URL then click GO

2. Write www.school.com as URL then click GO

The following page will appear if the network successfully work.

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Section 02: E-mail server

Network Topology

Learning Objectives

Connect a PC to a server.

Configure a server to be a Email server.

Sends Emails between devices in a LAN network

Introduction:

The Email server is a server that used to provide email services between devices either

through a LAN network or through a WAN network.

Task 1: Setup and Test

Step 1. Set up the network topologyD. Add a 2 pcs to the work area.

E. Add a server to the work area.

F. Add a switch to the work area

G. Connect pcs directly to the switch by using straight cable.

H. Connect the switch directly to server using straight cable.

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Step 2. Observe the default DNS settings.

F. Click the Server. The server configuration window opens,

G. Click the Config tab. The Global Settings appear. Change the display name to Email

Server.

H. Click the Interface button on the left then click on FastEthernet. Set the following static

IP address to 192.168.100.5 and Subnet mask to: 255.255.255.0.

I. Click the services button on the left then click on DNS and set the following settings:

o DNS Service: on

o Name : school.como Address: 192.168.100.5

J. Click on Add then save

Step3. Observe the Email settings

A. Click the Server. The server configuration window opens,

B. Click the services button on the left then click on Email and set the following

settings:

o Domain Name: school.com

o User: student1o Password: 1234

C. Click on set then click on (+)D. Repeat these steps using the followings:

o Domain Name: school.com

o User: student2o Password: 1234

E. Click on (+).

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Step 3. Configure Email on the client workstations.

Click the PC1 in the logical workspace. Click the Desktop tab and click the Email button fill the

window as the followings:

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Click the PC2 in the logical workspace. Click the Desktop tab and click the Email button fill the

window as the followings:

Step 4. Test the Network

Click the PC1 in the logical workspace. Click the Desktop tab and click the Email button and

then make a test:

A. To send an email from the current PC to another one.

1. Click on Compose

2. Set TO: student2@school.com

3. Set Subject to: HI

4. Write your message

5. Click on Send9

6. Go to PC2

7. Click the Desktop tab and click the Email button

8. Click on Receive button

9. Check if the inbox appear as the followings:

B. To send an email from PC to itself.

1. Click on Compose another time

2. Set TO: student2@school.com

3. Set Subject to: HI

4. Write your message

5. Click on Send

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