Chapter 4

Protocol Stacks

All Material Taken from Faster Smarter Network+ Certification by Melissa Craft

TCP/IP

Transmission Control Protocol/Internet Protocol

Constantly transforming to meet changing needs

Was developed before OSI model Contains many protocols with the entire suite Has four layers

TCP/IP

Host-to-host Transport Layer

Provides reliable data transport between 2 devices, regardless of type of physical media

Uses ports for identifying which application data is received from so that when it is reassembled is delivered to the correct one

TCP

Connection-based protocol which is designed to guarantee data delivery

Requires added control information (added overhead)

Relies upon ACK packets. If they aren’t received when expected, TCP retransmits the data.

Utilizes “sliding window” mechanism which enables multiple packets to be sent simultaneously

Full-duplex data exchange

User Datagram Protocol (UDP)

Does not use ACK packets, not reliable Much less packet overhead than TCP Does not guarantee data delivery Much faster than TCP

The Internetwork Layer and IP

Deals primarily with addressing and routing data

5 protocols work at this level Internet Protocol (IP) Internet Control Message Protocol (ICMP) Address Resolution Protocol (ARP) Reverse Address Resolution Protocol (RARP) Internet Group Membership Protocol (IGMP)

IP Addressing

Identifies network addresses without relying on physical addresses

Contains both network segment address and device (node) address

32 bits in lengths (8 bytes) Numbers range from 0 to 255 for each octet

130.218.134.61

5 Classes of IP Addresses

Class A-First Octet is between 0 and 126 0-126.0.0.0

Class B-First Octet is between 128 and 191 128-192.0.0.0

Class C-First Octet is between 192 and 223 192-223.0.0.0

Class D-First Octet is between 224 and 239 224-239.0.0.0 (Reserved)

Class E-First Octet is between 240 and 255 240-255.0.0.0 (reserved)

Address Masks

An address mask determines which portion of an IP address identifies the network and which portion identifies the host. Like the IP address, the mask is represented by four octets.

Address Class Address Mask

A 255.0.0.0

B 255.255.0.0

C 255.255.255.0

DNS (Domain Naming System) Names

A Fully Qualified Domain Name (FQDN) requires host name and DNS domain name microsoft.com edtech.kennesaw.edu

More “human friendly” naming system

IPX/SPX

Internetwork Packet Exchange/ Sequenced Packet Exchange

Novell protocol suite IPX is similar to IP (connectionless) SPX is similar to TCP (connection-oriented) Provides file, print, and application services Also provides directory service (tree)

IPX Addressing

Uses “watchdog packets” which are sent to inactive stations. If the packet is not returned within a set period of time, the server will terminate the connection

Uses the MAC address as the IPX node address portion

Small overhead, good speed

IPX Addresses

Utilize network number (4 bytes), MAC address (6 bytes), and socket address (2 bytes) 2AFF:3829:8FC6:7788:AAAA:0004

IPX Routing Routing Information Protocol (RIP)

Distance Vector protocol Dynamic routing table management Sends messages to neighboring routers only Similar to falling dominos, can cause broadcast storms

Netware Link Services Protocol (NLSP) Link state routing protocol Uses algorithm to enable routers to receive firsthand

information about status of other routers on the network

SPX

Provides guaranteed deliveryVery high overhead, speed is lessenedSends acknowledgment packets in both

directionsProvides error checking, end-to-end

flow control, sequencing, and error correction

Netware Shell

Provides intermediary service between network & non network aware applications

Makes decisions regarding accessing the network or not Example: Printing from Microsoft Word to a

network printer

Service Advertising Protocol (SAP)

Ensures that all network devices are aware of networking services

Broadcasts are sent every 60 seconds from server to its neighbors

Netware Core Protocol (NCP)

Used to access file, print, and security services

NCP allows workstations (clients) to perceive remote services in the same way they perceive local services

NetBIOS Extended User Interface (NetBEUI)

Designed to work on small LANs Is not routable! Uses NetBIOS names for identifying network

devices (16 bytes in length) Devices can have more than one name

(aliasing) One name is considered permanent-usually

taken from MAC address

NetBEUI Interoperability

Can be used in routed environment, but it must be tunneled through routable protocol (usually TCP/IP)

NetBIOS names must be resolved to IP addresses Formerly handled through LMHOSTS file (text file

located on each computer) Nowadays the Windows Internet Naming Service

(WINS) is used by Windows servers to map IP addresses to NetBIOS names (more centralized than LMHOSTS files, easier to administrate)

AppleTalk

Used to connect Apple & Macintosh computers in peer-to-peer configurations

Simple, inexpensive, flexible Very chatty due to constant broadcasting to

ensure connectivity Not suitable for large environments TCP/IP is much more common

AppleTalk Addresses

Dynamically assigned Node addresses between 1 and 254 Network administrators can assign other

network addresses (cable ranges). This requires a router (sometimes called seed routers).

AppleTalk Suite Protocols

AppleTalk Address Resolution Protocol (AARP) AppleTalk Echo Protocol (AEP) AppleTalk Filing Protocol (AFP) AppleTalk Transaction Protocol (ATP) Datagram Delivery Protocol (DDP) Name Binding Protocol (NBP) Printer Access Protocol (PAP) Routing Table Maintenance Protocol (RTMP) Zone Information Protocol (ZIP)

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