Transcript IP address. - Seneca - School of Information & Communications

Introduction to
Networking Concepts
Lesson 1
Skills Matrix
Technology Skill
Objective Domain
Objective #
Configuring IPv4 and IPv6
Addressing
Configure IPv4 and IPv6
addressing
1.1
TCP/IP Protocol Suite
• Network protocols provide the logical
“language” for communication over the
network.
• The most common networking protocol in
use today is Transmission Control
Protocol/Internet Protocol (TCP/IP).
IP Addressing
• By subdividing TCP/IP networks into smaller
groupings called subnets, the administration
of a TCP/IP network can be as centralized or
as decentralized as the needs of a particular
organization might dictate.
• The largest TCP/IP network in the world,
which is “owned” and administered by
hundreds and thousands of separate
entities, is the Internet.
IP Addressing
• For any computer or host to communicate on a
TCP/IP network, it must be configured with a valid
IP address.
• Each IP address consists of two components:
– network address — This portion of the IP address is
shared by all TCP/IP hosts on a particular network or
subnet.
– host address — This comprises the portion of the IP
address that is unique to a particular computer or
host.
• Both combined form a unique IP address across an
entire TCP/IP network.
IP Addressing
• In addition to the IP address, each TCP/IP host
must be configured with the following:
– subnet mask — Used to identify which network the
TCP/IP host resides on by defining where the
network address stops and the host address begins.
– default gateway — Allows a host to communicate
with devices that reside on a remote network or
location.
•You don’t need a default gateway if it is does not
need to communicate outside of the host’s own
subnet.
IPv4 Addressing
Alternate Configuration Tab
• Allows for a
second address
to be assigned to
a network
interface.
IPv4 Addressing
• The most commonly used version used today.
• Based on 32-bits (four bytes, or octets).
• 232 (4,294,967,296) possible addresses.
• Some of the possible addresses are reserved
• IPv4 addresses are commonly represented using
what is called dotted-decimal notation, in which
the decimal value of each byte is shown, using
periods to separate the bytes:
10.27.3.1
192.1.120.84
192.5.18.102
Classful Addressing
• The field for the network number was a
different length for different classes of
network, and the remaining bits were used
for the host number.
• Each network class had a different
maximum number of nodes.
• The first one to four bits identified the
network class, and the remaining bits
comprised the network and host address
fields.
Classful Addressing
Class A Networks
• Had the most significant bit as “0” and used
the remainder of the first octet for the
network number.
• There were 126 Class A networks, with a
maximum of 16,777,214 hosts in each.
• Note that the number of valid networks and
hosts available is always 2N – 2
(where N is the number of bits used and the
2 adjusts for the special function of the first
and last address in each network).
Class B Network
• Class B networks had the two most
significant bits as “10,” with the remainder
of the first two octets, or fourteen bits,
representing the network number.
• There were 16,384 Class B networks, with a
maximum of 65,534 hosts in each.
Class C Networks
• Class C networks had the three most
significant bits as “110,” with the remainder
of the first three octets as the network
number and the last octet as the host
number.
• There were 2,097,152 Class C networks,
each with a maximum of 254 host
addresses.
Classful Addressing Examples
• 15.234.48.34
– Default subnet mask is 255.0.0.0
– Network address is 15.0.0.0
– Host address is 0.234.48.34
• 203.23.47.234
– Default subnet mask is 255.255.255.0
– Network address is 203.23.47.0
– Host address is 0.0.0.234
Class D and Class E Networks
• Network addresses with the four most
significant bits “1110” (Class D, multicast).
– Multicast addressing is used to deliver to
multiple host simultaneously using the most
efficient strategy to deliver the messages
over each link of the network only once,
creating copies only when the links to the
multiple destinations split.
• “1111” (Class E, reserved) were also
defined.
Classless Inter-Domain Routing (CIDR)
• When classful network addresses started became
scarce, public Internet Service Providers (ISPs)
started to allocate many small networks to their
customers.
• Breaks the network address space into CIDR
blocks
• The number of masked bits is specified with the
CIDR notation.
• Example:
– 10.0.0.0/8 would describe 8 bits masked and 24
bits for host numbering.
Classless Addressing Examples
• 15.234.48.34/24
– Subnet mask is 255.255.0.0
– Network address is 15.234.48.0
– Host address is 0.0.0.34
• 203.23.47.234/16
– Subnet mask is 255.255.0.0
– Network address is 203.23.0.0
– Host address is 0.0.47.234
Subnetting
• Logical partitioning of an organization’s
network address range into smaller blocks.
Subnetting Example
• Network Address (Enteprise/corporation):
16.52.0.0/16
– Default Subnet mask is 255.255.0.0
• Site 1 has network address of:
16.52.1.0
– With subnetting, the subnet mask becomes
255.255.255.0
• Site 2 has network address of:
16.52.2.0
– With subnetting, the subnet mask becomes
255.255.255.0
Private Addresses
• For convenience, several network address
blocks were reserved for private networks.
• Defined as non-routable outside of the
private network.
Network Address Translation (NAT)
• Hosts using private network addresses can
communicate with public networks only by
using network address translation (NAT),
• Enables routing by mapping their private
network address to a different, routable
network address.
Loopback Address
• Specifies itself at address 127.0.0.1
IPv6 Addressing
• Near exhaustion of the 4-billion-plus IP
addresses available through IPv4.
• While the use of private IP networks and NAT
have alleviated the problem somewhat, a
long-term solution is still required.
• IPv6, the next generation of the TCP/IP
protocol, was developed to provide a
significantly larger address space for current
and future implementations of TCP/IP
networks.
IPv6 Addressing
• IPv6 uses 128 bits, or 16 bytes, for
addressing.
– Providing 2128 (about 340 billion) unique
addresses.
• Uses eight groups of four hexadecimal digits,
separated by colons.
• IPv6 includes a few other enhancements for
performance and security.
– IPSec.
IPv6 Addressing
• IPv6 addresses are 128 bits in length and
expressed in hexadecimal notation. For example,
– 2001:0db8:85a3:08d3:13
– 19:8a2e:0370:7334
• If an IPv6 address contains a series of sequential
zeroes, the address can be shortened to use a
single zero in each group, or else the entire
grouping can be represented using a double colon
(::).
– 2001:0000:0000:0000:0000:0000:0000:7334
– 2001:0:0:0:0:0:0:7334
– 2001::7334
IPv6 Addressing
• IPv6 networks can be expressed using CIDR
notation such as 2001:0db8:1234::/48 to
represent the 2001:0db8:1234 network
configured with a 48-bit subnet mask.
Domain Name System (DNS)
• Domain Name System (DNS) used for name
resolution.
• It translates from Host name to IP
addresses.
• HOSTS files also translate from Host name
to IP addresses.
• Prevents you from remembering addresses.
– Instead, remember meaningful logical
names.
Domain Name System (DNS)
Traditional Top-Level Domain Names
• .com – Commercial
• .edu – Education
• .gov – Agencies of U.S. federal government
• .net – Computers of network providers and
ISPs
• .org – nongovernmental and nonprofit
organizations
Fully Qualified Domain Name (FQDN)
• Describes the exact relationship between a
host and its DNS domain.
• Example:
computer1.sales.adatum.com
– Host name is computer1
– In the sales domain, which is in the adatum
second-level domain, which is in the .com toplevel domain, which is under the “.” root domain.
Static Addresses
• When administering TCP/IP hosts, you can
assign static IP addresses.
– Must be configured and maintained
manually.
– This can become a daunting, tedious task as
the number of systems grows to larger
numbers.
Dynamic Host Configuration Protocol (DHCP)
• Simplifies the problem by automating the
assigning, tracking, and reassigning of IP
addresses.
• Also to provide other important settings such
as the default gateway, subnet mask, DNS,
and so on.
Dynamic Host Configuration Protocol (DHCP)
DHCP Relay Agent
• DHCP relies heavily on broadcast messages.
• Broadcast messages are generally limited to the
subnet in which they originate and are not
forwarded to other subnets.
• A DHCP relay agent is either a host or an IP router
that listens for DHCP (and BOOTP) client messages
being broadcast on a subnet and then forwards
those DHCP messages to a DHCP server on a
remote subnet. The DHCP server sends DHCP
response messages back.
Routing
• The process of transferring data across a network
from one LAN to another, provides the basis for
TCP/IP communications on the Internet and nearly
all other corporate networks.
• By configuring two network interface cards (NICs)
within a Windows Server 2008 server, the server
can provide a means of transmitting data from one
network to another.
• For larger networks, the processing demands of
network routing are typically handled by dedicated
hardware-based routers.
Remote Access
• A Windows Server 2008 computer can act
as a remote access server, which can allow
remote network clients to access resources
on a network as though they were physically
connected to the LAN.
• The Windows Server 2008 remote access
server can provide remote access using
either dial-up connections via a modem or
else through a Virtual Private Network (VPN)
connection over the Internet or another
public network.
Network Access Protection (NAP)
• One of the principal challenges in corporate
networks is the ability to secure networks against
unwarranted access.
• Network administrators also need to protect the
network against “inside threats,” laptop computers
that are physically brought inside the corporate
network or that gain access to the company
network through remote access technologies such
as Virtual Private Networks (VPNs.)
• Windows Server 2008 provides the Network
Access Protection platform, which provides a policy
enforcement mechanism to control access to a
2008 network.
Summary
• Network protocols create a logical language
that allows computers to communicate.
• The most commonly used network protocol
on modern networks is the Transmission
Control Protocol/Internet Protocol (TCP/IP)
protocol suite.
• There are currently two implementations of
TCP/IP: TCP/IP version 4, or IPv4, and
TCP/IP version 6, or IPv6.
Summary
• Each host on a TCP/IP network needs to be
configured with a unique IP address.
• TCP/IP networks use the Domain Name
System (DNS) to map human-readable
machine names to IP addresses and vice
versa, such as mapping the
www.cpandl.com host name to the
10.10.1.104 IP address.
Summary
• Network administrators can use the Dynamic
Host Configuration Protocol (DHCP) to
automatically assign IP addresses to
multiple client computers.
• The Routing and Remote Access service
provides the ability to use a Windows Server
2008 computer as a router, which passes
network traffic from one TCP/IP network to
another, as well as remote access
capabilities using either dial-up or VPN
technology.
Summary
• To allow administrators to enforce network
security policies, such as mandatory antivirus or firewall configurations, Windows
Server 2008 has introduced the Network
Access Protection (NAP) enforcement
platform.
• Network addressing is fundamental to
successful communication between
systems.
Summary
• DNS provides name resolution to allow
meaningful names to be used to refer to
network addresses.
• DHCP is a simple, standard protocol that
makes TCP/IP network configuration much
easier for the administrator by dynamically
assigning IP addresses and providing
additional configuration information to DHCP
clients automatically.
Summary
• Clients may be configured to use APIPA or an
alternate static IP address configuration if
DHCP is unavailable.