Module 003 basic services

Engineered by Hackers. Presented by Professionals.
Basic Services
Module 00
H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa

Objectives:

DNS

DHCP

Web

Mail

FTP
Basic Services
H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa


Overview of Domain Name System
DNS is a hierarchical, distributed database that contains
mappings of DNS domain names to various types of data, such
as IP addresses
DNS is a hierarchical, distributed database that contains
mappings of DNS domain names to various types of data, such
as IP addresses
DNS is the foundation of the Internet naming scheme and the
foundation of an organization’s naming scheme

DNS supports accessing resources by using alphanumeric names
InterNIC is responsible for delegating administrative responsibility
for portions of the domain namespace and for registering domain
names
H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa


What Is a Domain Namespace?
H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa

Standards for DNS Naming

The following characters are valid for DNS names:
A-Z
a-z
0-9
Hyphen (-)
The underscore (_) is a reserved character
H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa

What Are the Components of a DNS Solution?

H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa

How Root Hint Works

Root hints are DNS resource records stored on a DNS
server that list the IP addresses for the DNS root servers
Root hints are DNS resource records stored on a DNS
server that list the IP addresses for the DNS root servers
H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa

What Are Resource Records and Record Types?

H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa

Why Use DHCP?

H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa

How DHCP Allocates IP Addresses

H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa

What Are DHCP Scopes?

H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa


Web server can refer to either the hardware (the computer) or
the software (the computer application) that helps to deliver Web

content that can be accessed through the Internet.

The most common use of web servers is to host websites, but there
are other uses such as gaming, data storage or running enterprise
applications

A user agent, commonly a web browser , initiates communication
by making a request for a specific resource using HTTP and the
server responds with the content of that resource or an error
message if unable to do so
Web Server
H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa


Email is one of the most popular applications on the Internet today

It is client-server model

In electronic mail terms, Terms for mail server are known as the
mail transport agent and the mail user agent for mail client -
or MTA and MUA for short
Mail Server
H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa


Typical MTA's are:

While typical MUA's are:

Microsoft's Outlook
Outlook Express
Evolution
Netscape Mail.
Mail Server
Microsoft Exchange,
MDAEMON
Sendmail
EXIM
Qmail
H c vi n Công Ngh Thông Tin Bách ọ ệ ệ
Khoa


File Transfer Protocol (FTP) is a widely accepted standard on
almost all platforms that have implemented TCP/IP

The objectives of FTP

Promote sharing of files

Transfer data reliably and efficiently.

Ports used for FTP

21: authentication

20: data transfer
FTP Server
H c vi n Công Ngh Thông Tin Bách ọ ệ ệ

Khoa


Non-essential protocols should be disabled or turned off

Following is a list of services that shouldn’t be offered on your
primary servers:

NETBIOS

Network File System (NFS)

X Windows services

R services, such as rlogin and rexec

Telnet

FTP

TFTP

NetMeeting

Remote control systems

Simple Network Management Protocol (SNMP)
Non-Essential Services and Protocols