I. Knowledge
of Networking Technology
67%
I.1 Basic
Knowledge 16%
I.1.1 Demonstrate
understanding of basic network structure, including
- the characteristics
of star, bus, mesh, and ring topologies, their advantages
and disadvantages
- star - a star
physical topology means that the nodes/devices are
all connected to a centralized hub or switch and
is commonly used for 10BASE5, 10BASE-T or 100BASE-TX
- pros: cabling
is inexpensive, easy to wire, more reliable and
easier to manage because of the use of hubs which allow
defective cable segments to be routed around;
locating and repairing bad cables is easier because
of the concentrators; network growth is easier
- cons: all
nodes receive the same signal therefore dividing
bandwidth; max computers is 1,024 on a LAN; max
UTP length is 100 meters (approx 330 ft); distance
between computers is 2.5 meters.
- bus - a bus
physical topology means that all of the devices
are connected to a common backbone; signal is sent
in both directions, but some buses are unidirectional;
can be used for 10BASE5, 10BASE2 or 10BROAD36
- pros: good
for small networks
- cons:
difficult to troubleshoot and locate where the
break in the cable is or which machine is causing
the fault; when one device fails the rest of the
LAN fails.
- mesh - a mesh
physical topology is when every device on the network
is connected to every device on the network; most
commonly used in WAN configurations
- pros: helps
find the quickest route on the network; provides
redundancy
- cons:
very expensive and not easy to set up
- ring - a ring
physical topology is when the devices are wired
in a circle, but almost always implemented in a
logical ring topology on a star physical topology.
Each device has a transceiver which behaves like
a repeater which moves the signal around the ring;
ideal for token-passing access methods
- pros: signal
degeneration is low; only the device that holds
the token can transmit which reduces collisions.
- cons:
difficult to
locate a problem cable segment; expensive hardware
- the characteristics
of segments and backbones
- segments - typically
a trunk of cabling connecting a device to a concentration
device or routing device, also a logical group of
devices which communicate within a given subnet
that is separated by a bridge, router, brouter,
switching hub, or multiplexer.
- backbones - the foundation
of the LAN/WAN where the servers are linked together
on a common series of concentration devices or that
are just a few hops away. This gives the servers
the most bandwidth to serve other devices including
other servers.
I.1.2
Identify the following:
- the major network operating
systems, including Microsoft Windows NT, Novell NetWare,
and Unix.
- MS Windows NT - A
networking operating system designed using a Directory
to manage certain resources. NT's primary file system
is NTFS (New Technology File System). Provides an
inherently GUI console at the server.
- Novell NetWare - A
networking operating system designed using a bindery
or Directory Service to manage most resources. Netware's
primary file system is a combination of FAT (File
Allocation Table) and DET (Directory Entry Table).
Provides an inherently text based and command prompt
console at the server.
- Unix - A network
operating system developed in the early 1970s at Bell Labs.
This system is known for its portability thanks to it being
programmed in the C language. Unix files consist of four types:
ordinary, directory, special (device files) and links (pointers
to other files). A Unix file system is a tree structure whose top
or start is called the root "/" directory. Permissions on files
consist of read, write and execute pairs applied to three users:
owner, group and other (e.g., rwxrw-r-- means that the owner has
read, write and execute permissions; and users other than the owner
or those that are a member of the group have read permission).
- the clients that best
serve specific network operating systems and their
resources.
- Windows NT Workstation
best serves Windows NT Server because of the common
NTFS file system and they are optimized to work
best with each other. Best file transfer throughput
would be NT Workstation.
- Novell NetWare works
well with most popular clients OS's such as DOS,
Windows 3.11, Windows 9x, Windows NT Workstation,
but the clients that serves NetWare are DOS flavors,
and DOS based OS's such as Windows 95/98 for file
sharing. Macintosh and OS/2 work with NT and NetWare
but work best with the NOS written for them.
- Unix specific clients
such as Sun Sparc stations work best with their
manufacturer's NOS.
- the directory services
of the major network operating systems.
- Windows NT uses a
directory service database that contains information
related to users, groups and computers. It can be
replicated between Domain Controllers by a schedule
or on demand. Windows 2000 uses Active Directory
which is a hierarchical security model, similar
to NDS.
- NetWare 3.x uses bindery
services, NW 4.x and 5 both use Novell Directory
Services (NDS). Bindery is restricted to the machine
it sits on, NDS uses a tree structure.
- Unix uses ???
I.1.3 Associate
IPX, IP, and NetBEUI with their functions.
- IPX - Internetwork
Packet Exchange. It's the Novell NetWare designed
protocol which is the default protocol during installation.
Packet sizes for Ethernet are approx 1500 bytes,
for Token Ring they are approx 4Kb. Performs addressing
and routing functions. Resides in Network Layer.
Requires some configuration.
- IP - Internet Protocol.
DOD standard designed for ARPAnet. Based on two
models, the DOD model (4 layers) and the OSI model
(7 layers), which is the Windows NT and Unix default
protocol during installation. Requires a lot of
configuration. IP functions on the Internet layer
of the DOD model and on the Network layer of the
OSI model. A connectionless protocol responsible
for addressing and routing packets between hosts.
- NetBEUI - NetBIOS
(Network Basic Input Output System) Enhanced User
Interface. Microsoft designed protocol for fast
packet delivery in a small network without much
configuration, its shortcoming is that it's not
routable. It operates on the Network and Transport
layers of the OSI model.
I.1.4
Define the following terms and explain how each relates
to fault tolerance or high availability:
- mirroring - RAID 1:
Duplicates a partition on another physical disk with
one data channel, 2 drives, 1 used for data, 1 for
parity, advantages are fault tolerance; disadvantages
are it's expensive and requires twice the disk space
- duplexing - RAID 1:
Duplicates a partition on another physical disk that
is connected to another Hard Drive Controller using
two data channels simultaneously, two data cables
and two DASD, 1 used for data, 1 for parity, advantages
and disadvantages are the same as mirroring but duplexing
provides much faster read speeds than mirroring.
- striping (with and without
parity) - data striping is when blocks or bits of
data are written to each drive in the array in succession.
It's used in most RAID levels and is great for improving
read/write speeds because the I/O request are being
distributed between all I/O data channels. Parity
checking relies on an extra bit called a parity bit,
which is used to compare the bit string to an odd
or even count. If the odd or even count is not matched
based on the setting of the parity bit, then the data
string is sent again. Extra drive space is used for
the parity bits. Not using parity will improve overall
data transmission because of the omission of the parity
bit calculation, but should be used when speed is
of greater importance than fault tolerance. RAID 5
provides the best fault tolerance because it uses
several drives with block interleaving, a distributed
check sum for parity and has fast reads.
- volumes - are active
segments of a physical server hard drive which may
be fully contained in a single hard drive, spanned
over several disks or multiple volumes can occupy
one hard drive.
- tape backup - offline
storage and is easily removable, slow read/write compared
to hard disk, high capacity on magnetic tape, excellent
choice for fault tolerance because it's cheap and
the media can be sent elsewhere for protection.
I.1.5
Define the layers of the OSI model and identify the
protocols, services, and functions that pertain to each
layer.
- Application - (layer
7) Allows applications to use the network. Handles
network access, flow control and error recovery.
messages are sent between layers
- Protocols - SMB,
NCP
- Services - Telnet,
FTP use TCP, TFTP, NFS, SNMP, SMTP use TCP
- Functions - User
interface with applications & Gateways
- Presentation - (layer
6) Translates data into a form usable by the application
layer. The redirector operates here. Responsible
for protocol conversion, translating and encrypting
data, and managing data compression. messages are
sent between layers
- Protocols - NCP
- Services - Telnet,
FTP use TCP, TFTP, NFS, SNMP, SMTP use TCP
- Functions - Gateways
- Session - (layer 5)
Allows applications on connecting systems to establish
a session. Provides synchronization between communicating
computers. messages are sent between layers
- Protocols - N/A
- Services - Telnet,
FTP use TCP, TFTP, NFS, SNMP, SMTP use TCP
- Functions - Gateways
- Transport - (layer
4) Responsible for packet handling. Ensures error-free
delivery. Repackages messages, divides messages
into smaller packets, and handles error handling.
segments of message fragments are sent between layers
- Protocols - SPX,
TCP, UDP and NetBEUI function on this layer
- Services - TCP/SPX
- connection-oriented communication for applications
to ensure error free delivery; UDP - connectionless
communications and does not guarantee packet delivery
between transfer points
- Functions - Gateways
function on this layer
- Network - (layer 3)
Translates system names into addresses. Responsible
for addressing, determining routes for sending,
managing network traffic problems, packet switching,
routing, data congestion, and reassembling data.
Datagrams are sent between layers
- Protocols - IPX,
IP, ICMP, ARP, RARP, RIP, OSPF, EGP, IGMP, NetBEUI,
DLC, and DecNET function on this layer
- Services - software
& hardware addresses and packet routing between
hosts and networks (IP/IPX); software addresses
to hardware addresses are resolved (ARP/RARP),
sends messages and reports errors regarding packet
delivery (ICMP), reports host group membership
to local multicast routers (IGMP)
- Functions - Routers
and Brouters function up to this layer
- Data link - (layer
2) Sends data from network layer to physical layer.
Manages physical layer communications between connecting
systems. Data frames are sent between layers
- Protocols - HDLC
(High-level Data Link Control); Supports asynchronous
and synchronous transmissions. Uses LLC flow control
- Services - Ethernet,
Token Ring, and other communications occur here
via frames. LLC - (802.2) Manages link control
and defines SAP's (Service Access Points). MAC
- (802.3, 802.4, 802.5, 802.12) Communicates with
adapter card.
- Functions - Switches,
brouters and bridges function on this layer using
the MAC sublayer
- Physical - (layer
1) Transmits data over a physical medium. Defines
cables, cards, and physical aspects. Data bits are
sent.
- Protocols - No protocols
function on this layer
- Services - Ethernet
(CSMA/CD), Token Ring (token passing), and other
communications occur
- Functions - Repeaters
and multiplexers function on this layer; bits
are sent across the wire
I.1.6
Recognize and describe the following characteristics
of networking media and connectors:
- the advantages and disadvantages
of coax, Cat 3, Cat 5, fiber optic, UTP, and STP,
and the conditions under which they are appropriate
- coax - commonly used
for thick ethernet, thin ethernet, cable TV and
ARCnet, coaxial cabling that uses BNC connectors;
heavy shielding protects data, but expensive and
hard to make connectors
- CAT 3 - UTP/STP can
be used for voice or data, but can be used for data
up to 10Mps. Good for cable segments to workstations
or printers
- CAT 5 - UTP/STP can
be used for voice and/or data, but data transmissions
up to 100Mps. Good as a backbone, but also good
for cable segments to workstations or printers since
price is dropping.
- Fiber optic - (IEEE
802.8) Cable in which the center core, a glass cladding
composed of varying layers of reflective glass,
refracts light back into the core. Max length is
25 kilometers, speed is up to 2Gbps but very expensive.
Best used for a backbone due to cost.
- UTP - Unshielded Twisted
Pair; uses RJ-45, RJ-11, RS-232, and RS-449 connectors,
max length is 100 meters, speed is up to 100Mps.
Cheap, easy to install, length becomes a problem.
Can be CAT 2,3,4 or 5 quality grades.
- STP - Shielded Twisted
Pair; uses RJ-45, RJ-11, RS-232, and RS-449 connectors,
max length is 100 meters, speed is up to 500Mps.
Not as inexpensive as UTP, easy to install, length
becomes a problem. Can be CAT 2,3,4 or 5 quality
grades.
- the length and speed
of 10Base2, 10BaseT, and 100BaseT
- 10Base2 - max length
185 meters, max speed 10Mps (Thin Ethernet)
- 10BaseT - max length
100 meters, max speed 10Mps
- 100BaseT - max length
100 meters, max speed 100Mps
- the length and speed
of 10Base5, 100Base VGAnyLan, 100Base TX
- 10Base5 - max length
500 meters, max speed 10Mps (Thick Ethernet)
- 100Base5 - max length
500 meters, max speed 100Mps
- VGAnyLan - max length
250 meters, max speed 100Mps
- 100BaseTX - max length
100 meters, max speed 100Mps
- the visual appearance
of RJ 45 and BNC and how they are crimped.
I.1.7
Identify the basic attributes, purpose, and function
of the following network elements:
- full- and half-duplexing
- half-duplexing - each
device in the configuration can send and receive
information, but only one at a time; while sending
the device cannot receive, very much like walkie-talkies.
- full-duplexing - each
device in the configuration can send and receive
simultaneously. The best example of this is the
telephone.
- WAN and LAN - A LAN
is a local area network that is a small collection
of workstations in a geographic area of less than
1 mile and is very fast for data transfer. A wide
area network is a network of LANs. A WANs geographic
location is considered to be global using advanced
routers. WANs are much slower than LANs but are increasing
in speed.
- server, workstation,
and host
- server - a device
providing resources to other devices on the network
typically found in a distributed processing environment
- workstation - a device
which accesses available resources from servers
typically found in a distributed processing environment
- host - an addressable
computer system on a TCP/IP network such as workstations,
servers, minicomputers, mainframes, and routers
which typically offers resources to network nodes.
- server-based networking
and peer-to-peer networking
- a peer-to-peer network
does not rely on the use of a central file server
to share file but each workstation relies on another
workstation to have it's resources made available.
They are very difficult to maintain security, must
be limited number of peers to keep administration
costs low, slow response time, but they are inexpensive,
no central point of failure and no special training
required.
- A server-based network
requires a central file server and a networking
operating system that can handle the job. They require
a separate machine and therefore expensive hardware,
an expensive NOS, and without the proper training
it is difficult to install and maintain. On the
other hand, data transfer speeds are greater, security
is more robust, LAN expansion is simpler, and there
are management tools available.
- cable, NIC, and router
- cable - provides the
pathway for network communications. It's a component
of a topology determined by the NIC and standard
being used. The most common types of LAN cabling
are coaxial, unshielded twisted pair, shielded twist
pair, and fiber optic.
- NIC - Network Interface
Card is component added to a computer circuit board
expansion slot and connects directly to network
cabling. NOS software is installed on the workstation
to allow communication between the workstation OS
and the server NOS.
- router - means a connection
between similar or dissimilar topologies using the
same protocol operating at the OSI Network Layer.
- broadband and baseband
- baseband transmissions
use the entire medium's capacity for a single channel
over digital signaling. Since only one signal at
a time can occupy a channel, the use of a MUX will
allow multiple devices to send multiple signals
using a single transmission medium. Provide excellent
throughput because the digital signal occupies the
entire channel.
- broadband transmissions
share the medium's bandwidth over multiple analog
channels unidirectionally. This is performed using
different frequencies and a process known as FDM
(frequency division multiplexing). Since these transmission
work very well over long distances, WAN communications
take advantage of this technology.
- gateway, as both a default
IP router and as a method to connect dissimilar systems
or protocols
- a default gateway
is an IP address used to forward packets from one
subnet to another subnet.
- a gateway that connects
dissimilar systems or protocols allows different platforms
to inter-operate, which adds expansion and
functionality to a LAN. A gateway basically grants
a workstation a direct connection to the host computer
and acts as a messenger between the two systems.
Gateways operate between the OSI Transport layer
through the Application Layer.
I.2 Physical
Layer 6%
I.2.1
Given an installation, configuration, or troubleshooting
scenario, select an appropriate course of action if
a client workstation does not connect to the network
after installing or replacing a network interface card.
Explain why a given action is warranted. The following
issues may be covered:
- knowledge of how the
network card is usually configured, including EPROM,
jumpers, and plug-and-play software
- use of network card
diagnostics, including the loopback test and vendor-supplied
diagnostics
- the ability to resolve
hardware resource conflicts, including IRQ, DMA, and
I/O Base Address.
I.2.2
Identify the use of the following network components
and the differences between them:
- hubs - a hub is a wiring
concentrator for a LAN or WAN that provides a central
attachment point for network cabling. Coaxial cable
doesn't use hubs. There are three types of hubs: passive
(absorbs some signal; no electronics to process data
signal), active (cleans signal; electronics to amplify
signal), and intelligent (managed & switching
hubs).
- MAUs - (Multistation
Access Unit) an access device used to connect the
main cabling structure to devices in use on a Token
Ring network. This device adds fault tolerance to
the network so that a single failure doesn’t stop
the whole network
- switching hubs - are
intelligent hubs which contain circuitry that very
quickly route signals between ports on the hub. This
method reduces bandwidth waste because only the device
which needs to receive the packet does, rather than
the entire network segment.
- repeaters - devices
that amplify and regenerate a signal to extend
the distance of a LAN
- transceivers - connect
different Ethernet nodes together in an organized
fashion across an individual Ethernet segment; allows
multiple Ethernet segment nodes to connect to each
other to create a segment.
I.3 Data
Link Layer 5%
I.3.1
Describe the following data link layer concepts
- bridges, what they are
and why they are used
- Bridges
are used to segment networks. They forward packets
based on address of destination node. Uses RAM to
build a routing table based on hardware addresses.
Some bridge types are capable of connecting dissimilar
network topologies. Will forward all protocols.
Regenerates the signal at the packet level
- the 802 specs, including
the topics covered in 802.2, 802.3, and 802.5
- 802.2 - LLC (Logical
Link Control manages link control and defines SAPs);
Adds header fields to identify upper-layer protocols.
It provides reliable, intelligent information to
otherwise dumb frames. Also, acts as a switch board
to make sure MAC frames find their way to the right
Network layer process.
- 802.3 - (MAC communicates
with adapter card) CSMA/CD - Ethernet; Provides
physical layer options including different topologies,
media types, data rates and signaling modes.
- 802.5 - (MAC communicates
with adapter card) Token Ring LAN; Uses token-passing
media access protocol across a physical star, logical
ring and differential Manchester encoding to provide
data rates
- the function and characteristics
of MAC addresses
- MAC addresses, which
are a.k.a physical addresses, operate on the data
link layer. Each address is unique 12-digit hexadecimal
ID number, which is hard coded to the network device
by the factory, and is used by devices to direct
their packets to other devices.
I.4 Network
Layer 5%
I.4.1
Explain the following routing and network layer concepts,
including
- the fact that routing
occurs at the network layer
- routers help organize
a large network into terms of logical network segments
using logical network IDs
- the difference between
a router and a brouter
- a router functions
on the network layer of the OSI model
- a brouter functions
as a bridge on the data link MAC sublayer and as
a router on the network layer.
- the difference between
routable and non-routable protocols
- a routable protocol
permits its packets to be sent beyond a single LAN/WAN
segment whereas a non-routable protocol's packets will
remain on the originating LAN segment
- the concept of default
gateways and subnetworks
- a default gateway
is the exit and entry point of a subnet.
- Subnetworks are a
division of the entire internetwork which are created
to provide security and/or reduced traffic over
a WAN or congested networks
- the reason for employing
unique network IDs
- unique network IDs
prevent confusion between devices and help them to
properly direct their packets/datagrams. When a router receives
a packet which is destined for a network ID on the other side,
the router will know how to behave.
- the difference between
static and dynamic routing.
- Static routing requires
human interaction to fill the routing tables and
to provide accurate IP addressing, subnet masking
and the default gateway of the router
- Dynamic routing uses
information from neighboring routers to fill the
routing tables, therefore, in a high volume environment
the human error factor is greatly reduced when adding
routes
I.5 Transport
Layer 4%
I.5.1
Explain the following transport layer concepts:
- the distinction between
connectionless and connection-based transport
- connectionless - internal
nodes along the message path do not participate
in error correction and flow control.
- connection-based - an
acknowledgement (ACK) verifies that the host
has received each segment of the message, which results in reliable
delivery service. If the ACK is not received after
a given time period, then the data is resent. If
segments are not delivered to the destination device
correctly, then the Transport layer can initiate
retransmission or inform the upper layers. Uses
segmentation, flow control, and error checking to
insure packet delivery
- the purpose of name
resolution, either to an IP/IPX address or a network
protocol
- name resolution helps
upper layer services communicate segment destinations
with lower layer services.
I.6 TCP/IP
Fundamentals 12%
I.6.1
Demonstrate knowledge of the following TCP/IP fundamentals:
- the concept of IP default
gateways
- a default gateway
is the entry and exit point of datagrams between
subnets
- as a packet passes
through a router, the TTL is decremented by at least
1 until the packet TTL reaches 0; this prevents a packet
from travelling forever
- if a packet is too
large for the gateway then it is fragmented with
the following information: 1) a flag which
indicates that there are other packets, 2) a fragment
ID to identify the fragment and 3) a fragment offset
to indicate how to reassemble the packets
- the default gateway
MUST have the same subnet mask as the network it
resides on
- the purpose and use
of DHCP, DNS, WINS, and host files
- DHCP - Dynamic Host
Configuration Protocol;
- dynamic allocation
of IP address, default gateway and subnet mask
to a requesting IP client; reduces administrative
overhead
- DHCP uses the BOOTP
protocol to communicate with clients and uses BOOTP
to cross routers if the router is RFC 1542 compliant
and has BOOTP forwarding enabled
- When setting up
a scope, the scope's range is limited to a particular
subnet
- Add a scope to provide
services for additional subnets.
- 4 step process:
client request, server offer, client select, server
acknowledges
- clients attempt to
renew after 50% of their lease life has expired
by sending a DCHPREQUEST packet
- clients will attempt
to renew again at 87.5% expiration of lease life
if DHCPREQUEST from before was not responded to
- to confirm IP assignment
use utilities such as IPCONFIG, WINIPCFG
- clients retain IP
assignment until lease expires or until a DHCPRELEASE
command is sent from client
- DHCP Relay Agent
will forward DHCP messages between clients and
servers
- DNS - Domain Name
Services
- Helps clients resolve
host names to IP addresses internally and externally
- Uses static mapping
in a hierarchical database (root-level/top-level/second-level/host
name)
- Can be used to resolve
NetBIOS names with NT if you check the box to
"Enable DNS for Windows Resolution" in the TCP/IP
properties configuration dialog box in the WINS
Address tab
- A CNAME is a method
of DNS aliasing for something such as a www or
ftp server
- You can setup zone
transfers between Primary and Secondary DNS servers
for fault tolerance
- WINS - Windows Internet
Naming Service
- Eliminates the need
for clients to send broadcasts for computer name
resolution
- Uses dynamic mapping
- Eliminated the need
for LMHOSTS files
- Process includes
1) WINS client registers its NetBIOS name and
IP Address at startup with WINS server, 2) WINS client
sends a name query request to the WINS server
to talk to another host, and 3) if IP and host
name are found in database then the WINS server
will send to requesting WINS client
- Upon proper shutdown,
the WINS client will send a name release to the
WINS server
- WINS requests are
routable datagrams
- WINS Proxy Agent
is used for non-WINS clients (UNIX) to resolve
NetBIOS names of MS clients; one proxy agent per
subnet but no more than two agents per subnet
- MS Clients can resolve
the host names of UNIX computers as long as the
host names are 15 char or less, no special chars
and the UNIQUE UNIX computer names + IP are entered
into WINS statically
- No WINS Macintosh
support
- HOSTS & LMHOSTS
files -
- HOSTS is for DNS
and UNIX, therefore they are case sensitive for UNIX
hosts
- Syntax is IP address
TAB host name. Multiple hosts can be on one
line BUT where the first instance of the IP
address is found will be the IP assigned to
that host name.
EX.
123.45.6.78 www.bubba.com www.bubbaco.com
- HOSTS is a static map
of IP addresses to host names of machines, typed into
a text file
- On NT can
be up to 256 char long
- Must have
one file on each computer that is not using
DNS
- Names are
read in order one at a time, so the most commonly
used names should be at the beginning of
the file
- LMHOSTS is for
WINS and is not case sensitive
- static map of
IP address to NetBIOS name
- Required for
non-WINS clients that use NetBIOS broadcasts
for NetBIOS name resolution
- Maps NetBIOS
name to IP address using a static text file
- Syntax example
on a PDC 123.45.6.78 sales #pre #dom:bubbaco
- On each BDC
put an entry for the PDC in the LMHOSTS file
- # means comment
unless in front of a special command such
as #pre, #dom, #include, #begin_alternate,
#end_alternate
- the identity of the
main protocols that make up the TCP/IP suite, including
TCP, UDP, POP3, SMTP, SNMP, FTP, HTTP, and IP
- TCP - Transmission
Control Protocol: a reliable, connection-based protocol; good
for large amounts of data with a lot of ACK overhead
- UDP - User Datagram
Protocol: an unreliable, connectionless protocol for
sending small amounts of data without the overhead of ACKs
- POP3 - Post Office
Protocol version 3: a method of transferring mail
files from a mail server to a mail client from it's
source
- SMTP - Simple Mail
Transfer Protocol: a method of transferring mail
files from a mail client to mail server prior to
the destination
- SNMP - Simple Network
Management Protocol: a management tool used to monitor
and control remote network devices which can poll
specific information from the agent
- FTP - File Transfer
Protocol: a fast and error-free method to transfer
files from host to host
- HTTP - HyperText Transfer
Protocol: the common protocol used on the World
Wide Web to transfer files from a server to a web
browser
- IP - Internet Protocol:
a connectionless protocol responsible for addressing
and routing packets between hosts
- the idea that TCP/IP
is supported by every operating system and millions
of hosts worldwide
- the purpose and function
of Internet domain name server hierarchies (how email
arrives in another country).
I.6.2
Demonstrate knowledge of the fundamental concepts of
TCP/IP addressing, including
- the A, B, and C classes
of IP addresses and their default subnet mask numbers
- Class A - network
ID start bit is 0 and default subnet mask is 255.0.0.0;
decimal range 1-126
- Class B - network
ID start bit is 10 and default subnet mask is 255.
255.0.0; decimal range 128-191
- Class C - network
ID start bit is 110 and default subnet mask is 255.
255. 255.0; decimal range 192-223
- the use of port numbers
(HTTP, FTP, SMTP) and port numbers commonly assigned
to a given service.
- Ports are assigned
by RFC 1060 to create a socket connection
- HTTP - port number
80/tcp
- FTP - port number
21/tcp
- SMTP - port number
25/tcp
I.6.3
Demonstrate knowledge of TCP/IP configuration concepts,
including
- the definition of IP
proxy and why it is used
- the identity of the
normal configuration parameters for a workstation,
including IP address, DNS, default gateway, IP proxy
configuration, WINS, DHCP, host name, and Internet
domain name.
I.7 TCP/IP
Suite: Utilities 8%
I.7.1
Explain how and when to use the following TCP/IP utilities
to test, validate, and troubleshoot IP connectivity:
- ARP - used to gather
hardware addresses of local hosts and the default
gateway, you can view the ARP cache and check for
invalid or duplicate entries
- Command syntax
- arp -a [inet_addr]
[-N [if_addr]]
- arp -d inet_addr
[if_addr]
- arp -s inet_addr
ether_addr [if_addr]
- command switches
- -a or -g - displays
the current contents of the arp cache
- -d - deletes the
entry specified by inet_addr
- -s - adds a static
entry to the cache, mapping an IP address to a
physical address
- -N - displays the
arp entries for the specified physical address
- inet_addr - IP address,
written in dotted decimal format
- if_addr - IP address
of the NIC whose cache should be modified, if
no IP address, the first NIC is used
- ether_addr - the
physical address in hex separated by hyphens
- Telnet - this is a terminal
emulation program that will allow you to run interactive
commands on the telnet server. Until a connection
is established, no data will pass and if the connection
should break telnet will inform you. Good for testing
login configuration parameters to a remote host.
- NBTSTAT - reports statistics
and connections for NetBIOS over TCP/IP. Use for DNS
and WINS name resolution, local cache lookup, and
referral to LMHOSTS and HOSTS files. Troubleshoot
name-to-address mappings with NBTSTAT
- Command syntax
- Nbtstat [-a remotename]
[ -A IPaddress] [-c] [-n] [-R] [-r] [-S] [-s]
[interval]
- Command switches
- -a remotename -
lists the remote computer's name table by the
remote computer's name
- -A IP address -
lists the remote computer's name table by the
remote computer's IP address
- -c - lists the contents
of the name cache, mapping each IP address to
a name
- -n - lists local
NetBIOS names
- -R - if LMHOSTS
lookup is enabled, then it will purge the name
cache and reload it from the LMHOSTS file
- -r - lists name-resolution
statistics for Windows networking
- -S - displays workstation
and server sessions, listing hosts by IP address
- -s - displays workstation
and server sessions, attempting to list hosts
by name
- interval - the number
of seconds between refreshes of statistics
- Tracert - used to determine the
route a packet took to reach its destination
- Command syntax
- Tracert [-d] [-h
maximum_hops] [-j host-list] [-w timeout] target_name
- Command switches
- -d - specifies that
IP addresses should not be resolved to host name
- -h maximum_hops
- can only search up to the specified number of
hops
- -j host-list - specifies
the loose source route
- -w timeout - waits
the number of milliseconds specified by timeout
for each reply
- NETSTAT - this command
displays protocol statistics and gets information
about TCP/IP connections
- Command syntax
- Netstat [-a] [-e]
[-n] [-s] [-p protocol] [-r] [interval]
- Command switches
- -a - displays connections
and listening ports and their current state, but
not the server sessions
- -e - displays Ethernet
stats
- -n - displays active
connections, listed by IP address
- -s - displays per-protocol
statistics for IP, ICMP, TCP, and UDP
- -p protocol - displays
active connection statistics for the chosen protocol
(TCP or UDP), can use with the -s switch for more
information
- -r - displays the
contents of the routing table
- ipconfig/winipcfg -
these utilities display IP-addressing information
for the local network adapter(s) or a specified NIC.
- Command syntax
- ipconfig [/all |
/renew [adapter] | /release [adapter]]
- Command switches
- /all - all information
about adapter(s)
- /renew - renew DHCP
lease information for all local adapters if none
is named
- /release - release
DHCP lease information thereby disabling TCP/IP
on this adapter
- FTP - this utility is
used to transfer files between server and client.
This is a reliable method of data transfer because
it uses TCP. There is a long list of session commands
for file management
- Command syntax
- ftp [-v] [-n] [-i]
[-d] [-g] [-s: filename] [hostname]
- Command switches
- -v - suppresses
any display server responses (@echo off in DOS)
- -n - prevents automatic
login when connection has been established
- -I - turns off interactive
prompting during file transfer
- -d - displays all
ftp commands exchanged between client and server,
for debugging
- -g - disables the
globbing capability
- -s: filename - specifies
a text file containing ftp commands and then runs
the commands within the file, similar to a batch
file
- hostname - the host
to connect to and MUST be the LAST parameter specified
- ping - will send ICMP
echo packets to verify connections to a remote host
(or local if using the loopback address)
- Command syntax
- ping [-t] [-a] [-n
count] [-l length] [-f] [-i ttl] [-v tos] [-r
count] [-s count] [[-j host-list] | [-k host-list]]
[-w timeout] destination-list
- Command switches
- -t - ping until
interrupted
- -a - ping address
and resolves host name
- -n count - send
number of echo packets
- -l length - send
echo packets of a specified size
- -f - sends a DO
NOT FRAGMENT command to gateways
- -i ttl - sets the
TTL field
- -r count - records
the route of the outgoing and returning packets
- destination-list
- specifies the remote hosts to ping, by domain
name or by IP address
I.8 Remote
connectivity 5%
I.8.1
Explain the following remote connectivity concepts:
- the distinction between
PPP and SLIP
- PPP - Point-to Point
Protocol - routes IP packets via a dial-up connection
and supports compression and IP address negotiation
- SLIP - Serial Line
Internet Protocol - routes IP packets via a dial-up
connection and does NOT support compression and
IP address negotiation by itself
- the purpose and function
of PPTP and the conditions under which it is useful
- PPTP makes possible
a secure connection across the Internet. Users can
connect to any ISP, use the ISP's network as a gateway
and then connect to the office network. The PPTP
packets are encapsulated into es and procedures
- the need to employ
data encryption to protect network data
- the use of a firewall.
II.
Knowledge of Networking Practices
33%
II.1
Implementing the Installation of the Network 6%
II.1.1
Demonstrate awareness that administrative and test
accounts, passwords, IP addresses, IP configurations,
relevant SOPs, etc., must be obtained prior to network
implementation.
II.1.2
Explain the impact of environmental factors on computer
networks. Given a network installation scenario, identify
unexpected or atypical conditions that could either
cause problems for the network or signify that a problem
condition already exists, including
- room conditions (e.g.,
humidity, heat, etc.)
- it's important to
setup the room with normal humidity to prevent
electrostatic discharge (ESD), air conditioning
to prevent CPU overheating and system shutdown
- put the equipment
in a secured cabinet in a secured room to prevent
someone from tampering with unsupervised equipment
during off hours
- the placement of building
contents and personal effects (e.g., space heaters,
TVs, radios, etc.)
- consider the effects
of heat on electrical signals, electromagnetic
interference (EMI) from power lines or unshielded
power cables as well as TV and radio interference.
Common sources of EMI are fluorescent lights,
elevator motors, large generators, and refrigerator
magnets.
- basements are often the
best places to store computer equipment because the ground
can absorb most air waves
- computer equipment
- other computer equipment
can effect the unshielded data cables because
of EMI, such as monitor radiation or CPU power
supplies
- if the computer
equipment is faulty then the network components
may appear to have problems
- sometimes diagnostic
software may point out faulty computer parts without
wasting time guessing at the problem
- error messages.
- These are clues
to help boil down the problem to the least common
denominator. Once isolated, the proper remedy
can be applied without too much guess work.
- Some error messages
are misleading and additional diagnostic software
may be required to make a more educated guess.
II.1.3
Recognize visually,
or by description, common peripheral ports, external
SCSI (especially DB-25 connectors), and common network
componentry, including
- print servers
- peripherals
- hubs
- routers
- brouters
II.1.4
Given an installation scenario, demonstrate awareness
of the following compatibility and cabling issues:
- the consequences of
trying to install an analog modem in a digital jack
- when an analog modem
is installed into a digital jack, such as a PBX,
you take the risk of burning out your modem
- that the uses of RJ-45
connectors may differ greatly depending on the cabling
- if you are cabling
for 10BASE-T then the use of 2 pairs of CAT 3
wires is sufficient, but if you plan to upgrade
to 100BASE-TX in the future then you will need
CAT 5 and 2 pairs of wires.
- that patch cables
contribute to the overall length of the cabling
segment.
II.2 Administering
the Change Control System 4%
II.2.1
Demonstrate awareness of the need to document the
current status and configuration of the workstation
(i.e., providing a baseline) prior to making any changes.
II.2.2
Given a configuration scenario, select a course of
action that would allow the return of a system to
its original state.
Do a full restore
from the previous day tape backup. Wipe out the
partition information and rebuild the operating
system and server services from scratch.
II.2.3
Given a scenario involving workstation backups, select
the appropriate backup technique from among the following
- tape backup
- folder replication
to a network drive
- removable media,
- multi-generation.
II.2.4
Demonstrate awareness of the need to remove outdated
or unused drivers, properties, etc. when an upgrade
is successfully completed.
II.2.5
Identify the possible adverse effects on the network
caused by local changes (e.g., version conflicts,
overwritten DLLs, etc.).
II.2.6
Explain the purpose of drive mapping, and (given a
scenario) identify the mapping that will produce the
desired results using Universal Naming Convention
(UNC) or an equivalent feature. Explain the purpose
of printer port capturing and identify properly formed
capture commands, given a scenario.
II.2.7
Given a scenario where equipment is being moved or
changed, decide when and how to verify the functionality
of the network and critical applications.
II.2.8
Given a scenario where equipment is being moved or
changed, decide when and how to verify the functionality
of that equipment.
II.2.9
Demonstrate awareness of the need to obtain relevant
permissions before adding, deleting, or modifying
users.
II.2.10
Identify the purpose and function of the following
networking elements
- profiles
- rights
- procedures/policies,
- administrative utilities,
- login accounts, groups,
and passwords.
II.3 Maintaining
and Supporting the Network 6%
II.3.1
Identify the kinds of test documentation that are
usually available regarding a vendor's patches, fixes,
upgrades, etc.
II.3.2
Given a network maintenance scenario, demonstrate
awareness of the following issues:
- standard backup procedures
and backup media storage practices
- the need for periodic
application of software patches and other fixes
to the network
- the need to install
anti-virus software on the server and workstations
- the need to frequently
update virus signatures.
II.4 Identifying,
Assessing, and Responding to Problems 6%
II.4.1
Given an apparent network problem, determine the nature
of the action required (i.e., information transfer
vs. handholding vs. technical service).
II.4.2
Given a scenario involving several network problems,
prioritize them based on their seriousness.
II.5 Troubleshooting
the Network 11%
II.5.1
Recognize the following steps as a systematic approach
to identifying the extent of a network problem and,
given a problem scenario, select the appropriate next
step based on this approach:
- determine whether
the problem exists across the network,
- determine whether
the problem is workstation, workgroup, LAN or WAN,
- determine whether
the problem is consistent and replicable, and
- use standard troubleshooting
methods.
II.5.2
Identify the following steps as a systematic approach
for troubleshooting network problems and, given a
problem scenario, select the appropriate next step
based on this approach:
- identify the exact
issue,
- recreate the problem,
- isolate the cause,
- formulate a correction,
- implememt the correction,
- test,
- document the problem
and the solution, and
- give feedback.
II.5.3
Identify the following steps as a systematic approach
to determining whether a problem is attributable to
the operator or the system and, given a problem scenario,
select the appropriate next step based on this approach:
- have a second operator
perform the same task on an equivalent workstation,
- have a second operator
perform the same task on the original operator's
workstation,
- see whether operators
are following standard operating procedure.
II.5.4
Given a network troubleshooting scenario, demonstrate
awareness of the need to check for physical and logical
indicators of trouble, including
- link lights
- power lights
- error displays
- error logs and displays
- performance monitors.
II.5.5
Identify common network troubleshooting resources,
including
- knowledge bases on
the World Wide Web
- telephone technical
support
- vendor CDs.
II.5.6
Given a network problem
scenario, including symptoms, determine the most likely
cause or causes of the problem based on the available
information. Select the most appropriate course of
action based on this inference. Issues that may be
covered include
- recognizing abnormal
physical conditions
- isolating and correcting
problems in cases where there is a fault in the
physical media (patch cable)
- checking the status
of servers
- checking for configuration
problems with DNS, WINS, HOST file
- checking for viruses
- checking the validity
of the account name and password
- rechecking operator
logon procedures
- selecting and running
appropriate diagnostics.
II.5.7
Specify the tools that
are commonly used to resolve network equipment problems.
Identify the purpose and function of common network
tools, including
- crossover cable
- hardware loopback
- tone generator
- tone locator (fox
and hound).
II.5.8
Given a network problem
scenario, select appropriate tools to help resolve
the problem.
If you have any questions,
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Network+
Questions
Special
Thanks to David
Schwartzberg - CNE, MCP for writing the original
Cramsession for this exam! |
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