TCP/IP

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TCP/IP Chapter 7

Chapter 7: TCP/IP 2

TCP/IP History

Developed in the 1970s

Created for use on the ARPANET

Used by UNIX

Predates the PC, the Open Systems Interconnection (OSI) model, and Ethernet

Platform and operating system independent

Chapter 7: TCP/IP 3

TCP/IP Standards

Developed using a collaborative process

Published as Requests for Comments (RFCs) by the Internet Engineering Task Force (IETF)

In the public domain

Chapter 7: TCP/IP 4

Advantages of a Multilayered Design

Platform independence – Separate protocols make it easier to support a variety of communicating Platforms

Quality of service – Provide level of service required

Simultaneous development – Can develop various protocols simultaneously

Chapter 7: TCP/IP 5

TCP/IP AND THE OSI MODEL

Chapter 7: TCP/IP 6

THE LINK LAYER

Transmission Control Protocol/Internet Protocol (TCP/IP) link layer protocols include Serial Line Internet Protocol (SLIP)

Point-to-Point Protocol (PPP)

Chapter 7: TCP/IP 7

THE INTERNET LAYER

The TCP/IP internet layer is equivalent to the Open Systems Interconnection (OSI) network layer.

Examples of Internet layer protocols include IP

Address Resolution Protocol (ARP)

Internet Control Message Protocol (ICMP)

Routing protocols: Routing Information Protocol (RIP) version 1 and 2

Open Shortest Path First (OSPF)

Chapter 7: TCP/IP 8

THE TRANSPORT LAYER

The TCP/IP transport layer is equivalent to the OSI transport layer.

Examples of transport layer protocols include TCP

UDP

Chapter 7: TCP/IP 9

THE APPLICATION LAYER

The TCP/IP application layer is equivalent to the session, presentation, and application layers in the OSI model.

Examples of application layer protocols include Domain Name System (DNS)

Dynamic Host Configuration Protocol (DHCP)

File Transfer Protocol/Trivial File Transfer Protocol (FTP/TFTP)

Hypertext Transfer Protocol (HTTP)

Simple Mail Transfer Protocol (SMTP)

Telnet

Simple Network Management Protocol (SNMP)

Chapter 7: TCP/IP 10

ARP

The Address Resolution Protocol (ARP) resolves logical network layer addresses to Media Access Control (MAC) addresses.

ARP is defined in Request for Comments (RFC) 826.

ARP requests and replies are broadcasts that can be generated by end systems and routers.

ARP broadcast messages are not forwarded by routers.


THE INTERNET CONTROL MESSAGE PROTOCOL (ICMP)

The ICMP protocol (described in RFC 792) is a connectionless network layer messaging protocol.

Two types of messages can be sent by end systems and routers: Error and diagnostic. Used to report error

conditions and perform diagnostic tests on a network

Query. Used to request information from another system


IP ROUTING BASICS

Routers are network layer devices that Connect similar or dissimilar data-link layer

architectures to form an internetwork. Use route tables to forward datagrams across an

internetwork. Datagrams are forwarded based on the logical

destination network layer address. The best path selection is determined by the least

cost metric. Routes to remote destinations are learned in two

ways: Statically Dynamically


DIRECTLY CONNECTED NETWORKS


STATIC ROUTES

Static routes are manually configured by an administrator.

There must be one static route for each destination network.

There must be a default static route.

When a specific route becomes unavailable, a new static route must be added and the old one must be removed.

Static routes do not generate broadcast traffic.

Suitable only for small networks


DYNAMIC ROUTES

Dynamic routes are automatically learned and advertised by routing protocols.

Routers use dynamic routing protocols to build their route tables and advertise route information.

Routing protocols, such as RIP and OSPF, can adapt very quickly to changes in the network.

Routes are either broadcast or multicast.

The best path selection is based on metrics.


DYNAMIC ROUTES (CONT.)

Suitable for large networks

Automatically compensates for network infrastructure changes

Reduces administrative workload


ROUTING TABLE INFORMATION

Each route entry includes the following information: The destination network and subnet mask

The IP address of the next gateway (or router) used to reach the destination

The specific outgoing interface used to reach the destination

The metric value associated with the route


MICROSOFT WINDOWS XP ROUTING TABLE


STATIC ROUTE EXAMPLE


STATIC ROUTE COMMANDS

The configuration of a static route varies, depending on the operating system of the computer or router you are using.

For Microsoft Windows Server 2003 you can use either Route.exe command line interface

Routing And Remote Access Console


STATIC ROUTE COMMANDS (CONT.)

For UNIX and Linux systems, use the Route command line interface.

For NetWare servers, you can use either Routecon.nlm or Inetcfg.nlm.


ROUTE.EXE SYNTAX

To add a static route, use the following command line syntax: ROUTE ADD [destination network] MASK

[subnet mask] [local interface address] IF [local interface number] METRIC [metric value for route]

For example: ROUTE ADD 192.168.3.0 MASK

255.255.255.0 192.168.2.2 IF 1 METRIC 1


DYNAMIC ROUTING PROTOCOLS

Routers use dynamic routing protocols to advertise and learn about networks.

There are two types of routing protocols: Distance vector

Link state


RIP (Routing Information protocol)

RIP is a distance vector routing protocol.

There are two versions of RIP: RIP version 1, or RIP v1 (defined in RFC

1058)

RIP version 2, or RIP v2 (defined in RFC 2453)

RIP uses the least number of hops to determine the best path to a destination.

The maximum hop count is 15 (16 = destination unreachable).


OSPF (Open Shortest Path First)

OSPF is a link state routing protocol defined in RFC 2328.

OSPF uses link costs with the lowest values to determine the best path to a destination.

Routers maintain a database of routes for the entire network.

Routers exchange route information through multicast advertisements.

OSPF supports load balancing and authentication.


APPLICATION LAYER PROTOCOLS

Provide the communication between a client program and a server program across a network

Run on TCP or UDP


DNS (Domain Name System)

Resolves Internet Protocol (IP) host names to logical network layer addresses (converts IP addresses to Hostnames)

Runs on top of UDP or TCP

Uses well-known port 53


DNS (Domain Name System) (CONT.)

A hierarchical namespace for computer networks – Identifies computers using names composed of 3 or more words, separated by periods.

Common Top Level Domains .edu .gov .mil .com .net .org


DNS (Domain Name System) (CONT.)

Top Level Domain

Second Level Domain


DNS Name Resolution

The DNS Name Resolution Process


DHCP (Dynamic Host Configuration Protocol)

Facilitates the automatic assignment of IP addresses


Uses well-known server port 67 and client port 68

DHCP


FTP (File Transfer Protocol)

Is a connection-oriented file transfer protocol

Runs on top of TCP

Uses well-known server ports 21 (for control) and 20 (for data)


TFTP (Trivial File Transfer Protocol)

Is a connectionless file transfer protocol

Runs on top of UDP

Uses well-known server port 69


HTTP (Hypertext Transfer Protocol)

Used to access Web services




SMTP (Simple Mail Transfer Protocol)

Is an e-mail protocol

Runs on top of TCP



SNMP (Simple Network Management Protocol)

Allows SNMP management devices to query clients for information and set network traps. Use to gather information about the network




THE TELNET (Terminal Emulation) PROTOCOL

Is a terminal emulation program that allows remote access and management of network devices

Runs on top of TCP



TCP/IP CONFIGURATION PARAMETERS Each TCP/IP Windows host must be

configured with the following parameters: IP Address Subnet Mask Default Gateway DNS Server Address Windows Internet Name Service (WINS)

Server Address Network Basic Input/Output System

(NetBIOS)/Host Name


TCP/IP AND WINDOWS

All current versions of Windows use the TCP/IP protocol stack by default.

When the operating system detects a network interface adapter, it automatically installs the network interface device driver and the following TCP/IP modules: Client for Microsoft Networks

File and Print Sharing for Microsoft Networks

Internet Protocol (TCP/IP)


INSTALLING TCP/IP COMPONENTS


THE INTERNET PROTOCOL (TCP/IP) PROPERTIES DIALOG BOX


THE IP SETTINGS TAB


THE DNS TAB


THE WINS TAB


THE OPTIONS TAB


SUMMARY

The TCP/IP protocol stack consists of four layers: link, internet, transport, and application.

ARP resolves logical network layer addresses to MAC addresses.

ICMP is a messaging protocol used to report IP errors and query hosts for information.

Routers connect networks. They use static or dynamic routing protocols to learn and advertise routes.

Application layer protocols provide services to IP clients, such as file transfer and e-mail capability.

IP hosts must be configured with an IP Address, Subnet Mask, Default Gateway, DNS Server Address, WINS Server Address, and other parameters to communicate on a network.

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TCP/IP