11 NETWORK PROTOCOLS AND SERVICES Chapter 10. Chapter 10: Network Protocols and Services2 NETWORK PROTOCOLS AND SERVICES Identify how computers on TCP/IP

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NETWORK PROTOCOLS AND SERVICES

Chapter 10

Chapter 10: Network Protocols and Services 2

NETWORK PROTOCOLS AND SERVICES

Identify how computers on TCP/IP networks communicate

Explain how IP addresses and subnetting work

Explain how name resolution works, and identify the primary name resolution mechanisms that are used on Microsoft Windows networks


NETWORK PROTOCOLS AND SERVICES (CONTINUED)

Troubleshoot networking problems caused by cable connections, network adapters, modems, TCP/IP configuration, or name resolution settings.

Configure and troubleshoot Internet Connection Firewall

Configure Remote Assistance and Remote Desktop


TCP/IP CONFIGURABLE OPTIONS

IP address (mandatory)

Subnet mask (mandatory)

Default gateway (optional)

DNS configuration (optional)

WINS configuration (optional)


IP ADDRESS CLASSES

Class A addresses

Class B addresses

Class C addresses

Class D addresses

Class E addresses

Loopback addresses


IP ADDRESS VALIDITY

The first byte of the IP address must fall within the following ranges: 1 through 126

128 through 191

192 through 223

IP addresses that begin with 0, 127, or 224 through 255 are invalid

The host ID cannot be all binary 0s or 1s

No number in an IP address can be greater than 255


CHOOSING AN IP ADDRESSING SCHEME

10.0.0.0 through 10.255.255.255

172.16.0.0 through 172.31.255.255

192.168.0.0 through 192.168.255.255


SUBNET MASKS

Class A: 255.0.0.0

Class B: 255.255.0.0

Class C: 255.255.255.0


DEFAULT GATEWAY


DNS

Name resolution for TCP/IP clients

Service resolution

Resolve TCP/IP host names and FQDNs to IP addresses


TCP/IP HOSTS FILE


NetBIOS

NetBIOS Enhanced User Interface (NetBEUI) is a fast, efficient protocol, suitable for use on small networks.

Not used very much anymore

Will have to enable a WINS server or use the LMHOSTS file


WINS

In multiple-network environments, a WINS server can be used to maintain a database of NetBIOS name-to-IP address mappings, similar to a DNS server maintaining a database of host name-to-IP address mappings


LMHOSTS FILE

The Lmhosts file is a simple text file that contains IP addresses followed by the name of the host, similar to a TCP/IP hosts file. The Lmhosts file is stored in the System_root\System32\Drivers\Etc folder.


CONFIGURING LAN AND HIGH-SPEED INTERNET CONNECTIONS


ADDING A NETWORK COMPONENT


RENAMING, DISABLING, AND DELETING A LOCAL AREA CONNECTION


CONFIGURING TCP/IP


ALTERNATE TCP/IP CONFIGURATION BY USER-CONFIGURED SETTINGS


MANUAL CONFIGURATION OF TCP/IP PROPERTIES

Automatic configuration of TCP/IP properties is convenient, but there will be situations where you will want the control that is afforded by manual configuration


GENERAL NETWORK TROUBLESHOOTING

What isn’t working?

What is working?

Did whatever isn’t working ever work?

Does it work intermittently or not at all?

Has anything changed since the last time it worked?

Is there a relationship between things that are working and things that are not?


TROUBLESHOOTING TCP/IP

Are the computers involved physically connected to the network?

Does Event Viewer report any warnings or errors?

Are TCP/IP parameters configured correctly?

Is the computer receiving an address from the DHCP server?


TROUBLESHOOTING TCP/IP (CONTINUED)

Can the computer establish basic connectivity using the Ping command?

Is there a DNS or NetBIOS name-resolution problem?

Are the default gateway and additional routes configured in the local routing table?


TROUBLESHOOTING PHYSICAL CONNECTIVITY

Check the properties of the network adapter

Make sure that the network cable is connected to the network card


VERIFYING TCP/IP CONFIGURATION

TCP/IP settings to check include: Incorrect IP address

Duplicate IP address

Incorrect subnet mask

Incorrect or missing default gateway

Incorrect or missing DNS server

Incorrect or missing WINS server


PING


IPCONFIG


TROUBLESHOOTING DHCP CLIENTS

Use Ipconfig /renew to force the client to refresh the DHCP configuration

Ensure that the DHCP server is functioning and is not out of IP addresses

If the DHCP server is remote, verify that the DHCP Relay Agent is functioning


TROUBLESHOOTING BASIC CONNECTIVITY

If the client appears to have an appropriate TCP/IP configuration, you can perform basic connectivity testing using the Ping command


TRACERT COMMAND

The Tracert command-line utility can help you figure out exactly where along the route the breakdown happened


PATHPING COMMAND

The Pathping command is a combination of both Ping and Tracert, displaying information about packet loss at every router between the host computer and the remote one


TCP/IP HOST NAME RESOLUTION METHODS

Local host name

DNS cache

Hosts file

DNS server


NETBIOS NAME RESOLUTION METHODS

NetBIOS name cache

WINS server

Broadcast

Lmhosts file


UNDERSTANDING INTERNET CONNECTION FIREWALL

Limits the data that comes into a computer or a network

Does not limit what happens on a stand-alone computer or inside the network, or the data that passes between computers on a local network

Works independently of any networking hardware

Can keep a security log of discarded packets


ENABLING INTERNET CONNECTION FIREWALL


ICF LOGGING

Two available ICF logging options: Log Dropped Packets

Log Successful Connections


INTERNET CONTROL MESSAGE PROTOCOL (ICMP)


ALLOWING SERVICES IN ICF


ESTABLISHING A REMOTE ASSISTANCE SESSION

Start Menu – Help and Support


REMOTE ASSISTANCE CONSOLE


TAKING SHARED CONTROL OF THE USER’S COMPUTER

Can fully manipulate the computer

Can load and unload drivers

Can launch applications

Can View event logs

Cannot copy files from the user’s hard drive


REMOTE DESKTOP

Remote Desktop is designed to allow a user to have full control over her or his Windows XP Professional Edition desktop from another computer on the network


CONFIGURING REMOTE DESKTOP

Must have the check box selected.

Port 3389 must be opened on the firewall.


MANAGING REMOTE DESKTOP SESSIONS


CHAPTER SUMMARY

When configuring TCP/IP, you must configure an IP address and a subnet mask. Optionally, you can configure a default gateway and name server addresses.

A computer can obtain IP addressing information automatically or you can configure a static IP address.

Name resolution is the process of resolving a user-friendly name to an IP address. Name resolution mechanisms include DNS and WINS.


CHAPTER SUMMARY (CONTINUED)

When troubleshooting a networking problem, you should check for problems with cable connections, network adapters, modems, TCP/IP configuration, or name resolution settings.

Internet Connection Firewall provides a level of security against unwanted network traffic coming from outside your private network.


CHAPTER SUMMARY (CONTINUED)

Remote Assistance provides a way for a user to request help from an expert and even let that expert control the user’s desktop. Remote Desktop provides a way for a user to control his or her desktop while away from the main computer.

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11 NETWORK PROTOCOLS AND SERVICES Chapter 10. Chapter 10: Network Protocols and Services2 NETWORK PROTOCOLS AND SERVICES Identify how computers on TCP/IP