Luis' Brain Dumps
(If you scroll down, you will see much longer version. It had to be edited for the sake of space.)
This Networking Essentials Brain Dump is given courtesy of Luis Manuel García Suárez:
- 2 "connecting-cities-with-T1-links-questions"
1st) 2 T1 links between Berlin - Paris, Paris - Madrid ( why to take only US cities?)
-> fulfills the required, none of the optional
2nd) 3 T1 links Berlin-Paris, Paris-Madrid, Madrid-Berlin
-> fulfills everything
-2 NDIS/ODI questions
Beware of the wording, the principle is always the same. NDIS/ODI is a interface for multiple protocols to use the same network adapter.
One question talks about "what problem does NDIS/ODI overcomes", the other "what is the advantage of NDIS/ODI". In the last case the wording was something like "Let compliant transport protocols use compliant network adapters". It’s not just an NDIS/ODI characteristic, but the only right by exclusion of the rest of the possible answers.
- Two performance questions of the type "network traffic increase from 30% to 70%" in a 10BaseT network
Required: Reducing network traffic 50%.
Optional: Reducing cost, not affecting administration, not affection funtions
Proposed: Change all Ethernet componet with Ethernet switches.
I said that this fulfills required and both optional
- 3 "protocol analyzer" questions.
a) How to measure network traffic on a packet basis.
Here I was not sure, because another option was cable tester.
b) How to meaure traffic over the time
Other possibilities were TDR, Oscill. and an apparatus I never heard from
c) How to identify a failing network adapter
- 3 or 4 Router/Bridge/Repeater/Gateway questions
a) connect two TCP/IP LANs -> I said router, because TCP/IP is routable (I know that you could take everything but the solutions were exclusive)
b) connect two LANs with TCP/IP and NetBEUI without loosing funtionality -> I said brouter
c) connecting device for different protocols -> gateway
- Troubleshooting
2 scenarios where you measure different resistences.
In the first a RG58 A/U had 0 resistence in end-to-end -> change cable
In the second two groundings -> network must have only one.
You notice that a computer sometimes can access resources, other times not. Same thing happened to the others. The network had RG58 U and RG58 A/U cables -> change all RG58 U to RG58 A/U
- A question about routable protocols
I marked all execpt NetBEUI, DLT and LAT
- A server which performs processing power for client computers is
a) a file server
b) a application server
You could mark both, I did only "application server", although that was one of my greatest doubts.
- A scenario telling about different adapters used. The question was, why is there a conflict with IRQ3.
Answer -> the computer used COM2 and COM2 uses IRQ3
- A small 10 computer network. Which protocol to use.
There was not NetBEUI among the answers, so I took IPX/SPX
-Another one where I had a great doubt, because the question was. "Which has less administrative tasks".
Scenario: Implement security in a network with W95 useres and NT server. User-access-security or password-protected resources.
I think both is possible. Which has less administrative task -> I don’s know. I mark User-access-security
- 2 questions to the following scenario:
You have a network with the data on the servers, in a separate room, NTFS and a lot of more good things. 2 hours downtime acceptable (I asked me "downtime" of what)
Required: You have to assure data protection, fault-tolerance,
Optional: Protection against virus, data access tracking
First solution - Doing backups, granting user-acces, virus-scans and RAID 5 and a lot of beautiful things but not auditing -> Fulfills required and all but tracking options.
Second solution - Doing backups, granting user-access, virus-scans and RAID 1 and a lot of beautiful thing more AND auditing -> Fulfills everything.
That´s all, folks!
And now, the LONG brain dump:
NE EXAM
1) I got 2 questions of the type : Required results - Optional results - Proposed solutions Which results does the proposed solution provide :ABCD in a scenario where three offices were to be connected by T1 links, much like in the "Networking Essentials" study book page 620. I think one of the required results were to keep information flow between the three offices even though one link failed. A map displayed the configuration : A pyramid situation in one of the questions, and a chain link situation in the other.
2)I also had an astonishing 3 questions where one used a ohmmeter to measure the resistance on a coax cable. A situation where you were to fix the problem after measuring for example 50 ohm on the end resistor( one question I think had 75 ohm, indicating wrong termination), infinity between the inner conductor and the outer shield (OK, one question said 0 that would indicate a short!) etc and decide if you should A)Change termination B) Change coax cables etc..
3) Had 2 questions that were totaly NT - related, showing a result%Processor Time and Page Faults /sec table from Performace Monitor and had you decide wheather a processor change or memory adding was the solution to increase performance.
4)What to use for measuring network performance over long period of time. Among the options were a Time domain reflectometer, Protocol Analyser (both wrong, logging with Performance Mon is correct) etc..
5)Which of the following would you use if you wanted a safe dialup connection: Among the options were SLIP (not safe), PPP (Correct) and some option that made no sense at all.
6) One classic concerning the fact that NETBEUI was not routable.
7) Which of the following can provide a WAN link with digital voice,data, and video etc.. and ATM, T1 etc were among the options.
one question - UNC naming scheme
one question - whether to choose a server based or peer to peer network.
General hints - brush up on differences between PPP & SLIP. Even though these arent mentioned in the "Networking Essentials" book, they actually are mentioned in Microsofts info on the test at their home site. Same goes for the DLC protocol. Hardly mentioned in the book (I think its in a OSI layer graph, but thats it). Just need to know that this protocol is needed when using network HP printers.
Well, thats about all I can remember. I took this in January so...(Ill remember to make a brain dump straight after the NT tests that are coming up later).
The MCP forum I mentioned earlier is closed this week, but Ive included 4 word documents, where Ive copy-paste the good hints from other people that have taken the tests. Might be helpful, but Ive only done this for NT4 Workstation,
NT4 server + Enterprise and an unsorted TCP/IP.
Networking Essentials - extra materials
Topics covered on Networking Essentials Test that aren't in the Study Guide
--File Server
--Network device that provides files on demand
--Fits the request/reply format
--part of the client server
--Application Server
--provides services directly
--Ex: SEQL Server and Exchange Server
--Not a server that serves up applications but an application that responds directly
--Connection Oriented vs. Connectionless Communication
--Connection oriented begins with an attempt to communicate and a go ahead response whereas connectionless does not require a go-ahead before it begins sending information
--Example: Phone conversations require a connection to be made before any information can be communicated so they are similar to Connection oriented communication; US Mail is like connectionless because there is no need to establish connection to send information - there is also no guarantee communication will be received
--Transceiver types
--transmitter and a receiver
--couples NIC to medium
--usually built-in, but also externally available
--physical connection between the medium and the computer
--Troubleshooting common answers:
--Netware -> frametype
--Token Ring-> Ring speed or protocol mismatch
--Ethernet -> transceiver type
--IRQ availability
--there must be an interrupt available for card to use
--available interrupt must be compatible with card
--***MEMORIZE THE IRQ TABLE***
--Select and appropriate networking medium
--based on cost, distance limitations, number of nodes
--wireless is chosen by number of remote users and difficulty of laying cable
--Fiber:
--greatest distance
--greatest bandwidth
--least amount of external interference
--greatest cost
--2 nodes to any pice of fiber is PTP (except FDDI)
--difficult to install
--easy to damage
--requires special trainings
--Coax:
--best for nodes with little change -> 10Base2
--thinwire is more flexible, no need for hub
--thickwire is best for backbones and medium to long hauls
--more immune to interference
--choice between thicket and thinnet comes down to cost and distance
--5-4-3 rule
--5: maximum number of segments
--4: maximum number of repeaters
--3: maximum number of active segments
--Cable lengths:
--100 meters (TP) 2 max devices
--185 meters (10Base2) 30 max devices
--500 meters (10Base5) 100 max devices
--Devices = pointers, repeaters, terminals
--TP is PTP from hub
--Token vs. Ethernet
--Token Ring is a guaranteed chance to transmit information while Ethernet is probabalistic (not guaranteed)
--Token: regulates the medium
--IEEE specs on BNC, T-connectors, cable types:
--802.3
--RG 58AU - Ethernet 10Base2 Impedence = 50 Ohms
--RG 62 - Arcnet Impedence = 75 Ohms
--RG 8 - thicknet Impedence =50 Ohms
--Where Repeaters, Bridges, Routers, and Brouters sit on the OSI model
--Repeaters -> Physical; only change media types
--Bridges -> Data -> MAC; only change media types
--Routers/Brouters -> Network; change physical media and architectures
--as they get smarter they move up the model
--Gateways: specialized devices that work at whatever levels they have to allow protocols to talk to each other
--Switch
--smart, fast, hub
--makes electrical isolation paths
--every path effectively has the full benefit of all bandwidth
--easier and cheaper to install
--Protocol choices
--IPX -> Netware access; easier to manage than TCP/IP
--IPX/SPX is the same as NWLink
--good general purpose solution
--not necessarily restricted to NetWare
--is routable, second best choice for LANs
--TCP/IP -> internet access, intranet use
--requires heavy management of IP addresses
--NetBEUI -> Basic, small Microsoft/LANmanager
--AppleTalk -> Macs
--DLC -> Directly attached printers and mainframe access ***Not routable***
--SLIP vs. PPP
--SLIP is same as TCP/IP
--connection protocols
--SLIP is older and used in UNIX
--not fully standardized
--doest have authentication or encryption
--only about IP
--higher overhead
--does not allow assignment of IP addresses
--PPP
--built as a standardized SLIP
--can negotiate passwords and encryption
--allows for dynamic IP addressing
--supports multiple protocols: NetBUIE, TCP/IP, IPX
--NetBIOS naming system
--15 character name limitation
--no minimum
--NDIS and ODI
--ODI eliminates need for custom driver for every protocol/NIC combination
--vendors create cards to ODI standard
--NDIS 3.0 -> multiple protocols and NICs
--NDIS 3.1 -> adds plug-n-play to 3.0
--NetBIOS universal naming convention:
\\servername\sharename\resource
--avoids need to assign a drive letter
--Establishing an administrative plan
--network management
--account management
--security
--any other specifics
--fault tolerance
--**memorize RAID levels**
--NTFS
--deploys all advanced security
--allows for setting of permissions and share access
--enforces local and network security
--Differences between user level and share level
--share is password/group oriented
--user level is based on permissions
--Results of performance monitoring
--CPU%
--page faults
--& of disktime
--CPU que length
--Disk que length
--If CPU is at 100% options include:
--get a faster CPU
--add another CPU
--split apps across multiple servers
--If disktime is to big options include:
--get a faster disk
--split disks
--High disktimes and pagefaults are often due to memory problems
--CPU que length
--number of processes waiting for CPU time to run
--shouldn't be higher than 1.5
--to large might indicate a need for multiple processors
--Disk que length
--number of processes waiting to be written to disk
--Domains
--group of computers that share a common accounts database
--workgroups are federations of computers without an accounts database
--create a domain with a PDC
--only one per NT domain
--multiple BDCs
--accounts database holds:
--individual computer accounts
--individual use accounts
--groups
--primary purposes of BDC:
--faster access
--fault tolerance
--if the PDC fails the BDC still operates but the account database is frozen until the PDC is restored or a BDC is promoted to PDC
--Four domain models
--Single
--only one domain and PDC
--all users and machines belong to the one domain
--BCD is not required, but recommended
--Master
--multiple domains connected to each other
--trust: one domain accepts the other domain's reliability
--allows first domain users to log on to second domain
--does not have to be two way
--allows for easy local administration
--easily scalable
--can have local BDC of trusted PDC without actual connection
--Multi-master
--takes over when Master is no longer scalable
--account domain is split into multiple PDCs with two way trusts
--resources choose a master to trust
--scaling beyond 100,00 limit
--difficult to keep masters in sync
--Complete
--every domain trusts every other model
--number of trust relations grows quickly
--only good reason for a complete trust is the merging of two
previously separate domains
--really only a temporary solution
Listing of Questions
What is a network and what benefits does it provide?
What are three capabilities that a network can provide?
Distinguish between the following types of networks: LAN, WAN, and internet.
What hardware and software components are required to create a network?
What is the OSI model?
What are the seven layers of the OSI model?
What is the function of the physical layer of the OSI model?
What is the function of the Data Link Layer of the OSI model?
What is a data frame?
What is a packet?
What is the function of the Network Layer of the OSI model?
What is the function of the Transport Layer of the OSI model?
What is the function of the Session Layer of the OSI model?
What is the function of the Presentation Layer of the OSI model?
What is the function of the Application Layer of the OSI model?
At which layers of the OSI model does a network protocol function?
At which layer of the OSI model do the following devices typically operate: repeater, bridge, router, and gateway?
Describe how is information sent through the OSI model.
What is the IEEE 802 model and how is it different from the OSI model?
What are the three main standards for network topologies defined by the IEEE?
What layers are present in the IEEE model that are not present in the OSI model?
What is the purpose of the OSI and IEEE network models?
Describe the three most common types of cabling media used in LANs.
What is Plenum cable?
Describe the key characteristics of Thinnet coaxial cable.
Describe the key characteristics of UTP.
Define the 5 categories of UTP. What is the minimum acceptable category for 10baseT.
What is fiber-optic cable and how does it work?
Describe the key characteristics of fiber-optic cable.
What is FDDI?
What is the recommended maximum length of cable for Thinnet, Thicknet, unshielded twisted pair (UTP) and fiber-optic?
List the pros and cons of coaxial, UTP and fiber optic cabling.
What is a backbone?
Describe the following potential problems with cable transmissions: attenuation, impedance, capacitance, and crosstalk.
What is a time domain reflectometer and how does it work?
What factors should be considered when choosing cable?
How are data transmission rates measured?
How long should it take to transfer the entire contents of a 1.44MB disk over a network rated at 10Mbps?
Distinguish between digital and analog transmissions.
What is bandwidth?
Distinguish between baseband and broadband transmission techniques.
Describe the characteristics of baseband transmission?
Describe the characteristics of broadband transmission?
What is multiplexing?
What is a topology? What are the three most common LAN topologies?
What is a bus topology?
What is the difference between a regular and a local bus?
What are the advantages and disadvantages of a bus topology?
Describe the features of a star topology?
What are the advantages and disadvantages of a star topology?
Describe the features of a ring topology?
What are the advantages and disadvantages of a ring topology?
What is a counterrotating ring?
What is a transceiver?
What is an interface connector? Describe the three common types of connectors and the cables they support.
What is a NIC?
What is the MAC address?
Describe three ways in which information is transferred between a NIC and the CPU.
What is a bus? What is the difference between a local and an expansion bus?
Distinguish among the following expansion bus architectures: ISA, MCA, EISA, VLB, PCI.
What settings are used to configure a NIC?
What is an IRQ and how is it used in configuring a NIC?
What is an IRQ conflict?
What are the common assignments for IRQs 0 to 15?
Which IRQs are commonly used for a NIC? How can I tell which IRQs are available?
What is the DMA Channel?
What is the base I/O port address and how is it used in configuring a NIC?
What is a base address?
How are memory addresses referenced?
What is the base memory address and how is it used in configuring a NIC?
Can two computers communicate without using a NIC?
What is the difference between parallel and serial ports?
What is a network architecture?
What is Media Access Control (MAC)? What is a MAC driver?
What is a collision?
What is CSMA/CD?
Describe how CSMA/CD operates.
What is a token passing?
Describe how token passing works.
Describe two types of error conditions on a token-ring LAN.
Compare token passing with CSMA/CD.
What are the 3 most common types of LAN architecture?
What is Ethernet? What IEEE standard does it conform to?
How does the nomenclature "10Base2" describe Ethernet cable?
Describe the characteristics of 10Base2 Ethernet.
Describe the characteristics of 10Base5 Ethernet.
Describe the characteristics of 10baseT Ethernet.
Describe the following Ethernet LANs: 10BaseF, 100Base-X, and 100VG-AnyLAN.
What is the Demand Priority media access control method?
What is Token Ring? What IEEE standard does it conform to?
Describe the Token Ring topology.
What is ArcNet? What IEEE standard does it conform to?
What factors should be considered when selecting a LAN architecture?
What is the most common bus topology normally used with the following architectures: 10base2, 10base5, 10baseT, Token Ring, and ArcNet?
What type of cable is normally used with the following architectures: 10base2, 10base5, 10baseT, Token Ring, and ArcNet?
What is the maximum length of cable segment for the following LANs: 10base2, 10base5, 10baseT, Token Ring, ArcNet and Fiber-Optic?
What is the maximum recommended number of nodes allowed with the following architectures: 10base2, 10base5, 10baseT, Token Ring, and ArcNet?
Compare and contrast Ethernet and Token Ring.
What is MAC driver?
What is a protocol?
What is a communication protocol?
What is a protocol driver?
What is a transport?
What is a monolithic protocol?
What is a session?
What is a datagram?
What is the difference between a session and datagram service?
What are data segmentation and sequencing services?
How does a protocol driver provide acknowledgment services?
How does a protocol driver support WAN services?
What is NetBEUI?
What is TCP/IP?
What is IPX/SPX?
What is DLC?
List the pros and cons of the following protocols: NetBUEI, IPX/SPX, TCP/IP.
What is IPC?
List several IPC mechanisms used in a network environment?
Describe how IPC mechanisms operate in the Windows 95 environment.
What are Windows Sockets?
What is NetBIOS?
What does NetBIOS do?
What is the Transport Driver Interface (TDI)?
What is a redirector and what does it do?
What is SMB?
What are network driver standards?
What advantages do network driver standards provide?
What is binding?
What is NDIS? What is ODI?
How does NDIS work?
What is the difference between NDIS 2.0.1, 3.0 and 3.1?
Provide an example of the benefits offered by NDIS and ODI.
What are the three components that make up ODI?
What is attenuation?
What is a repeater?
Is there a limit on the number of repeaters that can be employed?
What is a hub?
What capabilities does a hub provide?
What is an "intelligent" hub?
What is a MAU? What is a concentrator?
What function do bridges, routers and gateways perform?
Describe the capabilities of a bridge.
How does a bridge pass traffic between LAN segments?
Identify some potential problems with connecting Ethernet and token ring LANs with a bridge.
List some reasons for using a bridge in a network?
What is a transparent bridging? What is source routing?
What is a spanning tree algorithm?
What is a router?
Should I use a bridge or a router?
What is network partitioning?
Give an example of how network partitioning might be employed.
What is a gateway?
What is a server? What is a client?
What is client-server computing?
What is distributed computing?
Describe a dedicated server network configuration.
Describe a peer-to-peer network configuration.
Describe the conditions under which a dedicated server configuration is favored over a peer-to-peer configuration.
Describe the conditions under which a peer-to-peer configuration is favored over a dedicated server configuration.
Name several popular network operating systems that will support a dedicated server network.
Name several popular network operating systems that will support peer-to-peer networking.
What is a DBMS?
What is SQL?
What is OBDC?
What is Microsoft's Backoffice?
What is parallel processing?
Describe the characteristics of symmetrical multiprocessing.
Describe the characteristics of asymmetrical multiprocessing.
What is a CISC processor? What is a RISC processor?
Distinguish between the following file systems: FAT, HPFS, NTFS, & NCP.
What is RAID? What is striping?
Describe the 6 RAID levels. Which ones are supported by Windows NT Server?
What are groups? What are workgroups?
What is a home directory and how is it used?
What is UNC?
What is a share? What is a persistent share?
What is a network management system?
List 4 objectives of a network security system.
What are access rights?
What are permissions?
Describe the two security models: share-level and user level.
What is a logon procedure and what type of access restrictions can be implemented at logon?
What is an access control list (ACL)?
Describe how Windows NT controls access to network resources.
What are the characteristics of a C2 secure system?
Distinguish between private and public key encryption schemes.
What items should be checked if you suspect a cabling problem on the LAN.
List three steps to take if a specific operation cannot be performed on a workstation.
List several actions to take to resolve a network printing problem.
Describe the symptoms and identify the potential causes of a hardware conflict.
How can users install a complete copy of Windows on their workstations from the server? How can they install a shared version of Windows?
What is the most efficient way to copy the Windows system files to a server so that users can install
Windows over a network?
What does the /n switch do when used with the Windows SETUP command?
Which Windows files reside on the workstation when a shared copy of Windows is installed?
What are the three ways Windows can be installed from a network?
Describe the advantages and disadvantages of a local versus a shared copy of Windows for Workgroups.
What is the difference between the /n and /a switches used with the Windows SETUP command?
How can users install a local copy of Windows on their workstation from the network?
Microsoft Corp - Microsoft Press
"Official Curriculum! Official self-study guide to the fundamentals of current networking technology—core knowledge required for future MCSEs. Provides users with a general understanding of the technical concepts in the LAN & WAN environments."
896 pages, 1 volume, 1 CD
ISBN: 1-55615-806-8
Price: $99.95
Level: Int/Adv
Networking Essentials
Most people describe this book as useful, but it is not as directed at the actual exams as some of the other New Riders MCSE books.
MCSE Study Guide: Windows 95 & Networking Essentials by Lieigh Ann Chisholm, et al —NewRiders
"This guide will provide you with all the information you need to pass these two MCSE exams. Written by MSCEs and MCTs, this book contains hundreds of test questions, lists, tables, notes, tips, and tricks. Fast, effective & easy to use."
800 pages, 1 volume, 1 CD
ISBN: 1-56205-568-2
Price: $75.00
Level: Expert
Upgrading and Repairing Networks
By far the most comprehensive and useful book in my opinion. Covers concepts in depth. I used this book as a complement to the Microsoft Press book. Any subjects in the Microsoft Press book are covered much more in depth in this book.
Upgrading and Repairing Networks
Zacker, et al.
Que, 1996
pages 1000
ISBN: 0-7897-0181-2
Price: Bookpool $40.50, List Price $59.99
Level: Expert
Transcender's NetCert 2.0
Definitely worth the money! I highly recommend it!
Study Hints:
Don't take the exam relying solely on the Microsoft Press book.
Most people use this test as a starting place, but I recommend saving this exam for last. It is a difficult test requiring a knowledge base of all Microsoft's products and also requires one of the highest passing scores for the exams (793). Don't let this exam scare you, but don't take it lightly either!
My tips and links for the Microsoft Networking Essentials Exam
The Microsoft Self Study Kit is not as good as it should be, so I have put this page together. If you have anything you would like added or you can answer any of my questions please e-mail me. I will do my best to publish what I know to be correct. Thanks to all of you that have sent all that good info - keep it coming. Here we go:
Standards and Terminology
Crosstalk = overflow from an adjacent wire
Attenuation=The weakening or distorting of a transmitted signal as it goes further
Beaconing=The process of signaling computers on a ring system that token passing has been interrupted by a serious error.
Jitter=Instability in a signal wave form over time that could be caused by signal interference or an unbalanced ring in FDDI or Token Ring environments.
A UNC (Universal Naming Convention) \\computer name\share name for example \\Sales\MSWord
Peer to Peer - use when there are less than 10 computers and security is not an issue Client/Server - use when there are more than 10 computers or it may be expanded in the future and security is an issue.
User Level Security - Security is implemented by the Admin - security is based on user name and password
Share Level Security - each user has control of their shared resources (or "share") - used on peer to peer
*Which is a feature of Win NT Workstation: Shared resources with passwords (incorrect) User level passwords (correct)
*Which is a feature of Win 95: Shared resources with passwords (correct) User level passwords (incorrect)
Connection oriented communication is reliable
Connection-less orientated communication is unreliable
PPP supports dynamic IP addressing and SLIP does not. Also SLIP does not support compression but CSLIP does.
CSMA/CD -Carrier-sense multiple access with collision detection - check the cable for traffic - if there is no traffic it can send CSMA/CA - Carrier-sense multiple access with collision avoidance - signals the intent so send data b4 sending to help avoid collisions - is slower and less popular than CSMA/CD NDIS and ODI are designed to bind multiple protocols to a single NIC.
For the OSI Model click here and here. (?)
OSI Model - 7 layers
Application - represents the services that directly support user application, such as software for file transfer, database handle general network access, flow control, error recovery
Presentation - determines the format used to exchange data among networked computers -network's translator protocol conversion encrypting the data data compression; utility known as redirector operates at this layer
Session - allows two applications on different computers to establish, use and end a connection called a session performs name recognition like security placing checkpoints in the data stream dialog control between communicating processes
Transport - ensure that packet are delivered error free break long message into several packet and repackage it when in receive mode send an acknowledgment of receive flow control, error handling
Network - addressing messages and translation logical addresses to physical addresses determine the route from the source to the destination computer packet switching, routing, controlling the congestion of data if the network card on the Router can't transmit a data chuck as large as the source PC sends, the network layer on the Router compensates by breaking the data into smaller units
Data Link - sends data frames from the network layer to the physical layer receive end - it packages raw bits from the physical layer into data frames provide the error-free transfer of these frames sends a frame, it waits for an acknowledgment from the recipient
LLC - (Logical Link Control) upper sublayer of DL - manages DL communication and defines the use of logical interface points - defined by 802.2
MAC (Media Access Control) lower sublayer of DL - provides shared access for the NIC
Physical layer - is responsible for delivering error-free data between 2 computers - defined by 802.3, 802.4, 802.5, and 802.12
Physical -transmits the unstructured raw bit stream over a physical medium (cable) defines how the cable is attached to the network adapter responsible for transmitting bits (1 & 0)
I learned OSI very well, esp p172-175. You must also know where the network protocols live. They will give you a picture of it somewhere in your exam if you forget the order (esp of Transport and Network layers).
Application layer: layer7 Applications, e-mail, into user apps, initiates and accepts requests, higher level protocols live here, FTP,telnet,SMNP, SNMP, NFS and error RECOVERY.
Presentation Layer:layer6 Protocol conversion. The redirector lives here. Redirector grabs anything meant for network (files, prints anthing) and redirects to right place. All the different formats from all sources and all kinds are made into like a uniform common format that the rest of the OSI model can understand.
Session layer: layer5 Syncs & sessions. Connects two computers and controls, who send when, for how long, how, speeds, and oversees total control of packets. TCP, NWLink, named pipes, netBIOS and remember thatDLC lives here. This was one of the questions. Also remember that TCP(microsoft) is like SPX(Novell) and IP(microsoft) is like IPX (Novell). The above 3 layers are the application-level network service users.
Transport layer: layer4 "Trains" well I try and remember that the data streams breaks up into what looks like coaches of a train. The transport services layer. The error handling is done here. Differentprotocols have different requirements for length of data per packet, eg Token ring, Ethernet ATM all use different lenghts and these are formed and reformed in this layer. NDIS3, IP, SPX live here. Look p215.
The above 4 layers use gateways. There are Qs on which layers useg/.ways. ie App Pres. Session. Trans.
There are also Qs on Physical= repeater (or hub)
Data link layer=bridge
Network=router
These are gift marks so know them.
Where does SMB reside? Where do you find DLC?
Network layer layer3; Think of a big network, where the traffic is routed to, this being done by adding source and destination addresses, choosing best routes.(and uses routers.)
Data Link Layer layer2: look at the movies on the CD with Net essentials and see that DLL add CRC to other end of the data frames. Bridges work here, and the book is very terse on explantations. Basically the packets use network addresses (source and destination addresses) to get around; they can move around the world using logical addresses and are part of networking software, like Novell or Windows.This whole "network structure" actually sits on top of,( like another thing) ,on top of the LAN. The LAN being the basic underlying network, that's the nitty gritty physical network, where the the acual Network cards talk to each other.
The LAN really is only local and the DATA LINK LAYER conrols it. DLL is split into two LOGICAL LINK CONTROL and MEDIA ACCESS CONTROL. This may seem difficult at first but its not too bad. Think that the Media Access Control (MAC) controls the type of media being accessed ie media being Token ring, ethernet etc. also learn the 802.3~"ethernet", 802.4 ~arcnet (really only used by GM and obsolete), 802.5~token ring, and 802.12 Fiber.
The LOGICAL LINK CONTROL equates to 802.2 and is the "lowest level" controlling and managing the media.
Physical layer; layer 1; This is the hardware and physical cables. Repeaters (or hubs) amplify attenuated or wek signal here. (Another gift Q.) It just has to send 0 and 1, hi's and lows, on's and off's .
Data frames work at the two bottom layers and only inside the LAN using Physical or MAC addresses (usually factory or hard wired addresses). On page 176 looks like 10 of the gift Qs we got. These bottom 2 layers are called networking services. P179 talks about SAPs. On Novell these are like identifiers that broadcast (every 30sec??) to make presence felt that others know they are there.(This might be wrong info but that's how I understood it but go no Qs on it anyway).
BINDING understand ir well (p212) ,and effect with NDIS2 and 3. There were couple of questions there. (multiple cards, multiple protocols etc).
Easier way to remember the above:
"All People Seem To Need Data Processing" or
"Paula Did Networking Till She Passed Away"
IEEE 802 Committees
802.1 Internetworking
802.2 Logical Link Control (LLC)
802.3 CSMA/CD NETWORK (Ethernet)*
802.4 Token Bus NETWORK
802.5 Token Ring NETWORK*
802.6 Metropolitan Area Network (MAN)
802.7 Broadband Technical Advisory Group
802.8 Fiber-Optic Technical Advisory Group
802.9 Integrated Voice/Data Networks
802.10 Network Security
802.11 Wireless Networks
802.12 Demand Priority Access NETWORK (100VG-AnyLAN)
Planning
Ethernet topologies:
Type MHz Cable Type Length Connector
10BaseT 10 Cat 3,4 or 5 UTP (STP) 100m RJ-45
10Base2 10 thin-coax (RG-58) 185m BNC
10Base5 10 thick-coax (standard 500m DIX or AUI
Ethernet, thicknet)
1 0BaseFL 10 fiber-optic 2000m ?
100BaseT4 100 4-pair Cat 3,4 or 5UTP 100m R J-45
100BaseTX 100 2-pair Cat 5 UTP or STP 100m RJ-45
100Base 100 2-strand fiber-optic cable 2000m
RG-58 /U = Solid copper core - 50ohm impedance
RG-58 A/U = Stranded wire core
RG-58 C/U = Military spec. of RG-58 A/U
RG-59 = Broadband transmission such as cable TV
RG-6 = Larger in diameter and rated for higher frequencies than RG-59, but used for broadband transmissions as well
RG-62 = arcane networks
What is the difference in RG58U and RG58AU?
A/U signifies a stranded wire core instead of solid for thinnet. RG 58 U cable (solid core conductor) is NOT compatible with for ThinNet and is different that RG 58 A/U which IS used for ThinNet *HINT* replace RG58 U with RG58 A/U
1 meter =3.281 feet
*Know the different categories of UTP cable and what bandwidth they're capable of.
Category Mbps Type Physical Length Connector
1 ? Voice Telephone cable Help? MIC
2 4 Data 4 twisted-pairs Help? MIC
3 10 Data 4 twisted-pairs-3 twist per foot 100m RJ-45 or RJ-11
4 16 Data 4 twisted-pairs 100m RJ-45 or RJ-11
5 100 Data 4 twisted-pairs of copper wire 100m RJ-45 or RJ-11
Incorrect frame types can really throw off an IPX/SPX network.
IPX/SPX is great for Peer-to-Peer networking if NetBEUI is not a choice (hint: that's one of the questions on the test).
NetBEUI is a Transport protocol and is not routeable mainly used on Microsoft networks.
Mesh - uses routers to dynamically select the best path for the data
Know what a Mesh topology looks like (I had one that showed an exhibit of a mesh and asked me what it was). Check out page 782 of the SSK.
A subnet mask is used to mask a portion of the IP address so that TCP/IP can distinguish the network ID from the host ID. TCP/IP hosts communicate by using the subnet mask to determine whether the destination host is located on a local or remote network. The following
is a valid subnet mask: 255.255.0.0.
Repeater = Physical layer - takes a weak signal and regenerates it - doesn't translate or filter anything - can move packets from on physical media to another (i.e. can connect thinet to fiber-optic) - they are cheap - will pass a broadcast storm
Bridge = Data Link layer - does everything a repeater does - reduce traffic by segmenting the network by using a routing table- regenerate the signal at the packet level - not suited to WANs slower than 56K - will pass broadcast storms - read the source and destination of every packet - pass packet with unknown destinations - connect dissimilar networks (i.e.
Token Ring and Ethernet)
Router = Network layer - does filtering and isolating traffic - forwards particular protocols to particular addresses (other routers) - connect network segments - not all protocols are routeable (LAT and NetBEUI) - are used in complex network situations because they provide better traffic mgmt. than brides - don't pass broadcast traffic.
Brouter = combines best qualities of both a bridge and a Router - can act like a Router for one protocol and bridge all of the others (nonroutable) - delivers more cost-effective and more manageable internetworking than separate bridges and routers - connect 2 networks and limit unnecessary traffic - separate administrative networks - in other words use a brouter when using routeable and nonroutable protocols
Gateway = link 2 systems that don't use the same protocols, data formatting structures,
languages and architecture (i.e. NT and SNA) - stripes protocol stack and repackages it - used to connect a mini and mainframe (NT and an AS/400) - task-specific, slow and expensive.
Multiplexer= a device that can divide transmission into 2 or more channels In addition to protocol levels for each device, know what kind of compatible network each can join:
*Bridges - connect two similar networks and keep local IP address traffic local, but broadcasts go to the other side.
*Routers - connect similar protocol networks but only propagate packets that are not addressed to the local network and know about the router (in network control panels it the default gateway or route table that has to know about routers).
*BRouters are devices that can act like bridges or routers.
*Gateway (not to be confused with default gateways) are protocolconverters they change
TCP/IP to IPX/SPX etc.
*Ethernet Switches - they confine network traffic by actually only making connections between the source and destination systems. Wont help with broadcasts though, but will cut down traffic on backbone.
*Know the differences between Repeaters, Routers, Bridges, Brouters, Gateways, Hubs, etc, and in which cases you would need one or the other.
*In addition to protocol levels for each device, know what kind of compatible network each can join:
*repeater: different media, e.g, thicknet & thinnet
*bridge: same as repeater AND different architecture, e.g., token ring to ethernet
*gateway: same router AND different PROTOCOLS
X.25 = slow because of error checking and retransmission
Frame Relay = fiber optic
ATM = 155Mbps to 622Mbs
ISDN = divided into 3 channels 2 are 64Kbps (128Kbs combined,B channels, data stream)
3rd is 16Kbs (D channel, signaling and link mgmt.)
FDDI = 100Mbps - 500 computers over 100kilometers (62 miles) -
SONET = 51.84 Mbps
SMDS = 1Mbps to 34 Mbps
*What speed can X.25 and Frame Relay support?
1. Frame relay is cool. Frame relay gives you as much bandwith (transfer rate) as you want. You just pay for the bits transferred, instead of the time connected or the lease or watever. It does this by routing the packets through all of the provider's meshed network, (The cloud) just like the internet does. I guess it's only limited to the connection that you have to your provider.
X.25 is like frame relay except it's a little older and employs tons of error checking because its medium was plain old telephone wires (crosstalk and interference galore!) I guess these are related to your question about sliding TCP windows above, because they have to have packet assemblers/disassemblers (PAD's) ---the packets have to sit into the window and wait until everyone has gotten there and everyone is put in order before more can be sent. Of course, they don't nececarily have to be using a TCP sliding window. The PAD is actually at a lower level in the OSI model compared to tcp's sliding windows, I think. 2. X.25 can support up to 56 Mbps. Frame Relay, according to AT&T, is capable of "burst rates up to 1.5 Mbps initially and potentially 45 Mbps in later releases."
Implementation
Raid 0 - disk striping - disk striping divides data into 64k block and spreads it equally in a fixed rate and order among all disks in an array
Raid 1 - disk mirroring - actually duplicates a partition and moves the duplication onto another physical disk duplexing - is a mirrored pair of disks with an addition disk controller on the second drive
Raid 2 -Disk striping with ECC - when data is written the block is divided up and put across all drives - ECC is Error correction code
Raid 3 - ECC stored as parity - same as 2 but the ECC is cut down so that is only counts the number of 1's.
Raid 4 - disk guarding - one drive is a dedicated parity drive, data is striped to multiple drives and then its parity sum is calculated, which is written to the dedicated parity drive
Raid 5 - striping with parity - data is striped across multiple drives and then its parity sum is calculated, which is also striped across multiple drives (not a dedicated parity drive) needs a min of 3 drives.
Sector spacing - hot fixing automatically adds sector - recovery capabilities to the file system while the computer is running if bad sectors are found during disk I/O. the fault tolerance driver will attempt to move the data to good sector and map out the bad sector -only for SCSI, not EIDE or IDE
IRQ2(9)=EGA/VGA
IRQ3=COM2, COM4
IRQ4=COM1, COM3
IRQ5=LPT2 or Sound Card or NIC
IRQ6=Floppy Disk Controller
IRQ7=LPT1
A valid NetBIOS name must be under 15 chars, and have valid characters, (You know, not these kind: !@#$%^&*()|", etc, etc.) and it also must be unique on the netowork.
*Remember that Netbios names can be made valid over a WAN(i.e. routable) if you use IPX/SPX with Netbios support as the protocol.
Troubleshooting
Digital Volt Meter (DVM) is the most basic, all-purpose electronic measuring tool. Can tell you if cable is continuous or broken - can revel if two parts of the same cable are exposed and touching or a broken part of the cable is touching another conductor (piece of metal).
Protocol Analyzer=can look at packets to generate stats on network traffic - have a built in TDR - can provide insights into the network's behavior
Time Domain Reflectometer= sends sonar like pulses - looks for a break, short or imperfection in a cable - can locate a break within a few feet of the actual separation in the cable
Oscilloscopes=can display shorts, crimps, breaks and attenuation in cable.
When only one computer cannot connect to the network - it's probably a physical problem like the NIC or the cable connection - if you are using IPX/SPX it's probably an incorrect frame type.
*Know that you cannot wire-tap a FDDI network like you can Ethernet.
*Q: What of the following would you replace..
you tested the cable from center to edge and it read 0 ohm to infinite
you tested the T connector and it read 0 ohm
you tested the Terminator and it read 50 ohm
A: The cable appears to be broken since the ohm is reading 0 - infinite
Misc.
*Know what protocol is used to determine # of hops to a destination. Routing information protocol (RIP) uses distance-vector algorithms to determine routes.
*Ethernet has an MTU (maximum transfer unit) of 1514 bytes compared to Token Ring's 4k+.
*Your bridge/router between the two networks affects (effects?) the file transfer as well as the lan protocol (IPX/IP/NetBeui) you are using.
*Note2: For MS Networking Essentials Readers please substitute 'gateway' for the above mention bridge/router.
*There were a lot of questions on bridges vs. routers vs. gateways (when to use which one in this or that scenario). There were also a lot of 10base2, 10baseT comparison questions.
*Definitely know about which 802.x refers to which wire type (thick coax, thin coax, 10baseT, baseband vs. broadband, bus vs. star, Collision Detection vs. Token passing etc.
*DLC, LAT and NetBEUI are not routable. Almost everything else likely to be on the test is routable.
---- this question was on the test and replacing the RG 58 U cable with RG 58 A/U was the only correct answer ---
*Which of the following supports compression and error control: PPP and SLIP – SLIP doesn't support compression --- *Which of the following are routable protocols (name 5): TCP/IP, NWLink SPX, Apple Talk, NetBEUI and DLC (not NetBEUI or DLC and DLC is
not a valid peer-to-peer network protocol for computers)
*Know when to use a bridge, router, or gateway. There are about 12 questions where it puts you in a scenario and gives an action and asks if the action meets all or part of the goal. Those ones seem hard but if you've studied you can figure it out with deductive reasoning. It doesn't
ask any questions on definitions of the OSI model per se, but will ask how it pertains to network hardware. Know ATM, FDDI, etc and what they can be used for. Also have ALL the ethernet 802.3 characteristics down to a SCIENCE! There;s also a few where it asks something like "You've set up a PC and it inserts into the ring, but you can't see some of the servers, what is the problem?"
*Which is used for at least 100mbps: ATM, X25, 52kbps Digital line (ATM)
*Understand that if you are upgrading to 100BaseTX, you will need to also change network cards, hubs, etc
*Know that a terminator impedance is usually always 50 ohms
*Know the difference between a file & print server and an application server, i.e. the application server performs processor calculations
*you gotta know your TCP/IP quite well-ask about windows size changes lots of stuff in the situation questions.etc. Lots on Packet switching, ATM, switching hubs, T1 lines.
*OSI Layer wasnt asked so much except where does repeater(1) bridge(2) router(3) and gateway (4,5,6,7) fit in.
*Also, be prepared to answer some questions on some network troubleshooting equipment, a topology question that is obviously MESH that isn't in the self study guide, and an assortment of how long of a cable run can you have with 10-base-T, 10-Base-2, etc.
*Know the different types of coax and what they're used for (RG-8, RG-11, RG-58, RG-62)
*Know the difference between a Volt-Ohm Meter, a Protocol Analyzer, and a Time Domain Reflectometer, and what each one is used for.
*Know what protocol (RIP) is used to determine # of hops to a desination.
*Know the different types of network services (ATM, X.25, ISDN, Frame Relay, etc.) and what bandwidth they're capable of.
*Know what a Mesh topology looks like (I had one that showed an exhibit of a mesh and asked me what it was).
*Know that you cannot wire-tap a FDDI network like you can Ethernet.
*IPX/SPX is great for Peer-to-Peer networking if NetBEUI is not a choice (hint: that's one of the questions on the test).
* Acronyms suchs DHCP, WINS, NFS
* Different diagnostics tools such as TDR Time Domain Reflectometer, Sniffers, VOM Volt-Ohm Meter, oscilloscope
* Memorize the Media Types, UTP, ThickNet ThinNet, etc. max distances, how to implement.
* Using a router to resolve broadcast storms (freebie)
* Different network topologies including Mesh
Thanks to all of you that have answered my questions and shared your information to make this page possible!
(Remainder of brain dump not saved due to lack of space.)