CompTIA Network+ Certification Study Guide part 67 pdf

Standard for voice and data over twisted-pair media 802.9a Supplement to Integrated Services LAN: IEEE 802.9 Isochronous Service with CSMA/CD MAC Service 802.9b Supplement for Function

Table A.1 Listing of 802 IEEE Standards continued

Standard Subject\description

802.6j Standard for Connection Oriented Services on a Distributed Queue Dual Bus

Subnetwork of a Metropolitan Area Network 802.6k Distributed Queue Dual Subnetwork of a MAN Supplement for MAC bridging 802.6l Point-to-Point Interface for Subnetwork of MAN Specification for network

between two locations in a MAN 802.6m Subnetwork of MAN

802.7 Recommended Practices for Broadband LAN Provides recommendations for

the physical, electrical, and mechanical practices of broadband coaxial media 802.8 Fiber Optic Technical Advisory Group LAN Standard for fiber optic technology 802.9 Integrated Services (IS) LAN Interface at the MAC and Physical Layer Standard

for voice and data over twisted-pair media 802.9a Supplement to Integrated Services LAN: IEEE 802.9 Isochronous Service

with CSMA/CD MAC Service 802.9b Supplement for Functional Specification for AU to AU Interworking IEEE 802.9 802.9c Supplement to 802.9, Management Object Conformance Statement 802.9d Supplement to 802.9, PICS

802.10 Standard for Interoperable LAN Security (SILS) Standard for allowing secure

LAN products to interoperate using encryption 802.10a SILS Part A: The Model

802.10b SILS Part B: Secure Data Exchange Standard on protocol for secure data

exchange at Data Link Layer 802.10c SILS Part C: Key Management Standard on the management and distribution

of cryptography keys 802.10d SILS Part D: Security Management 802.10e LAN: Recommended Practice of Secure Data Exchange on Ethernet 2.0

Specifies secure data exchange on LANs using Ethernet 802.10f Secure Data Exchange: Sublayer

802.10g Standard for Security Labeling Within Secure Data Exchange 802.10h Supplement to Interoperable LM Security: PICS Proforma/Security Data 802.11 Standard for WLAN Standard for MAC and physical layer for wireless

networking 802.12 Demand Priority Access Method, Physical and Repeater Specifications,

100 Mb/s Standard dealing with 100 Mbs LANs 802.14 Standard Protocol for Cable-TV Based Broadband Communication Network

Standard for cable modems 802.15 WPAN

802.16 Broadband Wireless Access

Appendix A 647

Table A.1 Listing of 802 IEEE Standards continued

Standard Subject\description

802.17 Resilient Packet Ring

802.18 Radio Regulatory

802.19 Coexistence

802.20 MBWA

802.21 Media Independent Handoff

802.22 Wireless Regional Area Networks

1802.3-1991 IEEE Supplement to IEEE Std 802-1990: Methodology and Implementation for Attachment Unit Interface (AUI) Cable Conformance Testing

1802.3a Supplement to CSMA/CD Access Method and Physical Layer Specifications:

Methodology and Implementation for MAC Conformance Testing

1802.3b Supplement to CSMA/CD Access Method and Physical Layer Specifications:

Methodology and Implementation for PLS, Type 10, Conformance Testing

1802.3c Supplement to CSMA/CD Access Method and Physical Layer Specifications:

Methodology and Implementation for MAU, Type 10BASE-5, Conformance

Testing

1802.3d Conformance Test Methodology for IEEE Standards for LAN and MAN

Networks: CSMA/CD Access Method and Physical Layer Specifications Type

10BASE-T

While there are numerous IEEE standards that have been developed for

networking, the Network+ exam only expects you to know the basic

funda-mentals of a select few The standards that will be referenced in the exam

and that we’ll discuss in this appendix, are:

802.2 LLC

■

■

802.3 CSMA\CD

■

■

802.5 Token Ring

■

■

802.11 Wireless

■

■

802�2 LLC

Earlier in this chapter, we explained how 802 standards break the Data Link

Layer of the OSI model into two sublayers: the MAC and the LLC The LLC

is used to establish connections between computers, and is used by other

protocols defined by the 802 committee

When the LLC receives data in the form of a “frame” from the layer

above it (the Network Layer), it breaks it apart into smaller pieces that can

be sent over network media It also adds header information that identifies upper layer protocols sending the frame, and can also specify destination processes for the data The computer receiving the data will view this header information, and use it to reassemble the data into its proper format

802�3 CsMA/CD

On the basis of the original Ethernet network from Digital- Intel-Xerox (DIX), 802.3 is the standard for Ethernet networks today The only difference between 802.3 Ethernet and DIX Ethernet V.2 is the frame type The two Ethernet networks can use the same physical network, but devices on one standard cannot communicate with devices on the other standard

The MAC sublayer uses CSMA/CD for access to the physical medium CSMA/CD keeps devices on the network from interfering with one another when trying to transmit; if they do, a collision occurs To reduce collisions, CSMA/CD devices listen to the network before transmitting If the network

is “quiet” (no other devices are transmitting), the device can send data Since two devices can think that the network is clear and start transmitting at the same time, resulting in a collision, all devices listen as they transmit If a device detects another device is transmitting at the same time, a collision occurs The device stops transmitting and sends a signal to alert other nodes about the collision Then, all the nodes stop transmitting and wait a random amount of time before they begin the process again

CSMA/CD doesn’t stop collisions from happening, but it helps manage the situation when they do occur In fact, collisions are a normal part of Ethernet operation It’s only when collisions begin to occur frequently that you needed to become concerned

Ethernet has evolved over the years to include a number of popular spec-ifications These specifications are due in part to the media variety they employ, such as coaxial, twisted-pair, and fiber-optic cabling

The 10Base5 specification, commonly referred to as

■

original Ethernet specification and has a maximum distance of 500 m (approximately 1640 feet) with a speed of 2.94 to 10 Mbps

The 10Base2 specification, commonly referred to as

■

a thinner coaxial cable than 10Base5 does and has a maximum distance of 185 m (approximately 607 feet) with a maximum speed

of 10 Mbps

The 10BaseT specification uses twisted-pair cabling with a

maxi-■

■

mum distance of 100 m (approximately 328 feet) with a speed of 10

to 100 Mbps

Appendix A 649

802�5 token ring

Although Token Ring was first designed in the 1960s, IBM’s token passing

implementation did not become a standard until 1985 The 802.5 standard

was modeled after the IBM Token Ring network, which had been in use for

many years before the standard was developed

The 802.5 network introduced a unique access method: token passing

The Token Ring IEEE 802.5 standard passes a special frame known as a

token around the network This token is generated by the first computer

that comes online on the Token Ring network When a workstation wants

to transmit data, it grabs the token and then begins transmitting This

computer will send a data frame on the network with the address of the

destination computer The destination computer receives the data frame,

modifies it, and sends it onto the network back to the original computer,

indicating successful transmission of data When the workstation is finished

transmitting, the token is released back onto the network This ensures

that workstations will not simultaneously communicate on the network, as

in the CSMA/CD method

802�11 Wireless

The IEEE 802.11 standard addresses wireless networking This standard

includes the Wireless Access Point (WAP) devices and the wireless network

interface cards (NICs) that are used to send and receive broadcasts from the

cell or WAP device

The WAPs and wireless NICs can be set to use different frequencies to

allow for cell overlap This technology does not include the same technology

used by cell phones to manage the movement of PCs or mobile devices The

wireless NIC is set to a specific frequency and must be changed manually to

be able to communicate with another cell This means that a PC cannot be

moved from one cell area to another without changing frequency, unless for

some reason the cells operate on the same frequency and have no overlap

of coverage area.

Exam warning

IEEE standards are an important part of networking, and chances are that you’ll see

questions on them during the exam You’ll be tested on the main features of LLC, CSMA\

CD (Ethernet), Token Ring, and Wireless technologies Because Token Ring and Wireless

technologies are also part of the topologies we covered earlier in this chapter, you should

review these topologies to have a firm understanding of the standards Make sure you

are aware of the basics of 802.2, 802.3, 802.5, and 802.11.

Appendix B

uNdErSTANdING rEquEST For CoMMENTS

request for Comments

Request for Comments (RFCs) are documents describing a particular idea,

method, technology innovation or other concept that relates to

Internet-connected systems These documents are posted and presented to technical

communities as RFCs, and move through different classifications such as

informational or experimental Some end up on the standards track and

begin the journey as proposed standards While some RFCs go on to become

standards, others do not RFCs began in 1969 when the Internet was still

in its incarnation as the Advanced Research Projects Agency Network

(ARPANet) While not all of the RFC specifically deal with the Internet,

all of the Internet standards are written as RFC They focus on networking

protocols, communication issues, procedures, concepts, and other topics

RFC are created and maintained by the Internet Engineering Task Force

(IETF) The IETF is an organization that consists of vendors, network

admin-istrators, designers, researchers, and other professionals who are interested

in the operation and future of the Internet These people can provide

pro-posals to the IETF, which in turn provides a consensus on new standards

that should be added The proposals that are submitted are called “Internet

Drafts,” which are reviewed by working groups that specialize in specific

areas If a standard is developed as a result of the Internet Draft, it is written

as an RFC and categorized as a standard

using rFC

RFC are categorized using a number that is preceded by the prefix “RFC”

For example, the RFC dealing with the Domain Name System is RFC 1034

In reading a Request for Comment, you will find that there is a section that

shows the category or status of the document These categories include:

Standards-track Documents – have the status of being a Standard,

■

■

Draft Standard, and Proposed Standard This shows its current

state in becoming a standard

Best Current Practice – provides procedures and recommendations

■

■

Informational – provides information on various subjects This

■

■

category also includes the IETF’s joke RFC, such as RFC1217 (Memo from the Consortium for Slow Commotion Research [CSCR]), and RFC1438 (Statements of Boredom [SOBs]) Experimental – designates a particular practice or topic as

■

■

experimental in nature Historic – standards that are no longer used

■

■

Because the IETF doesn’t remove RFC, all of them are still available for viewing Ones that aren’t used are listed as being historic documents, but are still available for reference purposes This provides those using the RFC with the ability to review practices, principles, and protocols that are no longer in use, but that can be valuable if previous standards need to be reviewed

As is the case with the Institute of Electrical and Electronics Engineers (IEEE) standards, the number of standards published by the IETF is massive Rather than providing all of them here, Table B.1 provides a list of the Inter-net standards, many of which also relate to intraInter-nets and Inter-networks using Transmission Control Protocol/Internet Protocol (TCP/IP)

Table B.1 IETF Internet Related Standards

rFC Subject\description

RFC768 User Datagram Protocol RFC791 Internet Protocol RFC792 Internet Control Message Protocol RFC793 Transmission Control Protocol RFC821 Simple Mail Transfer Protocol RFC822 Standard for the format of ARPA Internet text messages

Test day Tip

The IETF’s RFC can easily be distinguished from IEEE standards by their title IEEE standards dealing with LANs begin with 802, while RFC begin with RFC.

RFC aren’t extensively covered in the exam, but they can still prove interesting and useful to review, and provide an additional source of information A full listing of RFC can be found at www.ietf.org/iesg/1rfc_index.txt, or by using the RFC online database at www.rfc-editor.org/rfc.html.

Appendix B 653

Table B.1 IETF Internet Related Standards continued

rFC Subject\description

RFC826 Ethernet Address Resolution Protocol: Or converting network protocol

addresses to 48-bit Ethernet address for transmission on Ethernet hardware

RFC854 Telnet Protocol Specification

RFC855 Telnet Option Specifications

RFC856 Telnet Binary Transmission

RFC857 Telnet Echo Option

RFC858 Telnet Suppress Go Ahead Option

RFC859 Telnet Status Option

RFC860 Telnet Timing Mark Option

RFC861 Telnet Extended Options: List Option

RFC862 Echo Protocol

RFC863 Discard Protocol

RFC864 Character Generator Protocol

RFC865 Quote of the Day Protocol

RFC866 Active Users

RFC867 Daytime Protocol

RFC868 Time Protocol

RFC891 Distributed Computer Network local-network protocols

RFC894 Standard for the transmission of IP datagrams over Ethernet networks

RFC895 Standard for the transmission of IP datagrams over experimental Ethernet

networks

RFC903 Reverse Address Resolution Protocol

RFC907 Host Access Protocol specification

RFC919 Broadcasting Internet datagrams

RFC922 Broadcasting Internet datagrams in the presence of subnets

RFC950 Internet Standard Subnetting Procedure

RFC959 File Transfer Protocol

RFC1001 Protocol standard for a Network Basic Input/Output System (NetBIOS)

service on a Transmission Control Protocol/User Datagram Protocol (TCP/

UDP) transport: Concepts and methods

RFC1002 Protocol standard for a NetBIOS service on a TCP/UDP transport: Detailed

specifications

RFC1006 ISO transport services on top of the TCP: Version 3

RFC1034 Domain names – concepts and facilities

Continued

Table B.1 IETF Internet Related Standards continued

rFC Subject\description

RFC1035 Domain names – implementation and specification RFC1042 Standard for the transmission of IP datagrams over IEEE 802 networks RFC1044 Internet Protocol on Network System’s HYPERchannel: Protocol specification RFC1055 Nonstandard for transmission of IP datagrams over serial lines: SLIP RFC1088 Standard for the transmission of IP datagrams over NetBIOS networks RFC1112 Host extensions for IP multicasting

RFC1122 Requirements for Internet Hosts – Communication Layers RFC1123 Requirements for Internet Hosts – Application and Support RFC1132 Standard for the transmission of 802.2 packets over Internetwork Packet

Exchange networks RFC1155 Structure and identification of management information for TCP/IP-based

internets RFC1201 Transmitting IP traffic over Attached Resource Computer networks RFC1209 Transmission of IP datagrams over the Switched Multi-megabit Data Service RFC1212 Concise Management Information Base (MIB) definitions

RFC1213 MIB for Network Management of TCP/IP-based internets: MIB-II RFC1350 The Trivial File Transfer Protocol (Revision 2)

RFC1390 Transmission of IP and ARP over Fiber Distributed Data Interface Networks RFC1661 The Point-to-Point Protocol (PPP)

RFC1662 PPP in High Level Data Link Control–like Framing RFC1722 Routing Information Protocol (RIP) Version 2 Protocol Applicability Statement RFC1870 Simple Mail Transfer Protocol (SMTP) Service Extension for Message Size

Declaration RFC1939 Post Office Protocol – Version 3 RFC2289 A One-Time Password System RFC2328 Open Shortest Path First Version 2 RFC2427 Multiprotocol Interconnect over Frame Relay RFC2453 RIP Version 2

RFC2578 Structure of Management Information Version 2 (SMIv2) RFC2579 Textual Conventions for SMIv2

RFC2580 Conformance Statements for SMIv2 RFC2819 Remote Network Monitoring MIB RFC2920 SMTP Service Extension for Command Pipelining

Appendix B 655

Table B.1 IETF Internet Related Standards continued

rFC Subject\description

RFC3411 An Architecture for Describing Simple Network Management Protocol

(SNMP) Management Frameworks

RFC3412 Message Processing and Dispatching for the SNMP

RFC3413 SNMP Applications

RFC3414 User-based Security Model for version 3 of the SNMP (SNMPv3)

RFC3415 View-based Access Control Model for the SNMP

RFC3416 Version 2 of the Protocol Operations for the SNMP

RFC3417 Transport Mappings for the SNMP

RFC3418 MIB for the SNMP

RFC3550 Real-time Transport Protocol (RTP): A Transport Protocol for Real-Time

Applications

RFC3551 RTP Profile for Audio and Video Conferences with Minimal Control

RFC3629 Unicode Transformation Format-8, a transformation format of ISO 10646

RFC3700 Internet Official Protocol Standards

RFC3986 Uniform Resource Identifier: Generic Syntax