Transcript No Slide Title

NETWORKING FROM A TO Z
• Your LAN
• Your WAN
• Your Wiring Plan
Adapted for EPA HS from Presentation to
Silicon Valley Conference
on
Nonprofits and Technology
May 9, 2001
Mark L. Miller, Ph.D.
The Miller Institute for Learning with Technology
[email protected]
The Alphabet Soup of Networking
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Architecture, ADSL, Analog
Bastion Host, Bandwidth, Bridge
Cat5, Cable Modem, Copper, Coax
DHCP, DSL, DES, DoS, DNS, DMZ
Extranet, Ethernet, Encryption
Facility, Firewall, FDDI, FE, Filter
Gigabit, Gateway, Gopher
HTTP, Hub, Hacker, Hosting, Hop
IDF, ISDN, intranet, ISP, IETF
Java, Jabber, Jitter, JPEG
Kbps, K56Flex, Kerberos, Kermit
LAN, Leased Line, Layer, LSB
MDF, Modem, Multimode, MPOE
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NIC, Network Diagram, Netmask, NAT
OSF, OC3, OEM, OSI, Octet
Packet, Port, Protocol, Plenum, POP
QoS, Quantization, Queue
Router, RAS, Rack, RJ45, RFC822
Server, Switch, SDSL, Static IP, SSH
T1, Tunnel, Topology, TCP/IP, Trojan
UPS, USB, UTP, UDP, UUCP, URL
VPN, Virus, VLAN, VAR, V.90
WAN, Wiring Plan, Wireless, WWW
X.25, XML, X11R6, X.400, X.500
YP, Y Modem, Yellow Wire, YMMV
Z Modem, Zone, Zero Delay Lockout
… and so on ...
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Overview
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What is a LAN? What is a WAN?
What is The Internet? What is an intranet?
What are Hubs? Switches? Routers?
Facilities Considerations
Network Drawings
Wiring Standards
Connection Types, Speeds,
and Protocols
Internet Service Providers
Network Security
For More Information
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What is a Local Area Network?
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Wires Within and Between Buildings on Same Campus
Connects Workstation Computers to Servers, Printers
Enables Resource Sharing (Files, Printers, Databases)
Facilitates Technical Support (e.g., Cloning, Backups)
Necessary for Wide Area Net and Shared Internet Access
The SERVER is the conceptual center of your network.
Desktop PC
Network Printer
Desktop PC
Server
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Desktop PC
Why Not Just Use Floppies?
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Floppies Are Notoriously Unreliable
Floppies Don’t Hold Nearly Enough Information
Floppies Don’t Facilitate Collaborative Work
Replication Costs More for Protons Than for Electrons
Floppies Don’t Help You Share Resources (Printers,
Scanners, Databases, Internet Access)
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What is a Wide Area Network?
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PC
Links Different Locations
within Your Own Organization
Similar to LAN but slower and
over greater distances
Printer
PC
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Can be Virtual (use Internet to
create VPN)
Bridge between two or more
LANs
PC
Server
PC
Printer
PC
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Server
PC
What is The Internet? What is an
intranet? What is an extranet?
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An internet is any network of computer networks
The Internet is the global, public network of networks
An intranet is a private internet within an organization,
typically hidden behind a firewall
An extranet is a semi-private internet allowing data exchange
across organizations (e.g., customer-vendor)
See: http://www.useit.com/alertbox/9709b.html
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What are Hubs?
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A hub is the active element which turns a collection of wires
into a network. It is the “hub” of a network. Most common
for modern networks is a “Star Topology”
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What are Switches?
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A switch is an active element much like a hub. However, the
entire “bandwidth” is available on every port, rather than
being shared among the ports. Think of a hub as a “partyline” phone, whereas a switch represents Direct-inbound-dial.
A 24-port 10/100
Mbs switch is
nominally
24 x 10 x 2 faster
than a 24-port
10BaseT hub
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Network Drawings
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LAN Diagram
WAN Diagram (may combine with LAN if simple)
Logical Versus Physical:
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Logical Diagram Indicates Topology/Connectivity
Physical Diagram Indicates Scale, Layout
Legends Should Indicate Type of Run, Speed
Do not rely on color to convey critical information
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Wiring Standards
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Copper (within a building)
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Fiber (between buildings)
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Cat3 (telephone quality, 10 Mbs at 300 feet)
Cat5 (data quality, 100 Mbs at 300 feet)
Cat5e, Cat6 (for gigabit speeds)
Multimode (Most common, least expensive)
Single mode (Higher speeds per length)
Hybrid (Possible future-proofing approach)
Wireless (mainly for laptops)
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802.11 (11 Mbs, typically within a few hundred feet)
Can help in situations where wiring is infeasible
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A Typical
Equipment
Rack
84”
MDF Plan
for Mission
Hospice of
San Mateo
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19”
Facilities Considerations
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Locked closet for equipment rack(s)
Accessibility of Equipment on Racks
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Access from front and back
Main Distribution Frame (MDF)
Intermediate Distribution Frame (IDF)
Adequate power
Ambient temperature
Length of cable runs (affects type of cabling)
Cable runs must not violate fire breaks
Plenum cable required if hot air returns
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What are Routers?
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A router is a specialized, dedicated computer for connecting
local area networks together into internets (e.g., from
Ethernet LAN to T1 WAN). It sends each packet of data to
the right location.
To Accounting
To The Internet
To Sales
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Protocols
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The “language” spoken between computers on a network
Internet Protocol (TCP/IP) is most popular and important
Others include:
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IPX/SPX (Novell)
NetBEUI (Microsoft)
AppleTalk (Apple)
Most can co-exist on same wire
Others (e.g., Token Ring) require different “topology”
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Internet Service Providers
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Getting on the Internet involves 2 distinct services:
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An Internet Service Provider, who provides:
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A Data Communications Provider, who provides
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IP Address(es)
Domain Name Service (optional)
Web Hosting or Co-Location (optional)
Access to Major Internet Trunks, Centers (MAE-WEST)
Peering Arrangements
A wire from you to the ISP
Both services are often provided by a single vendor.
See: www.thelist.com
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Connection Types and Speeds
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Analog Modem (up to 56 Kbs)
Leased Lines (up to 64 Kbs, no dial delay)
ISDN (up to 128 Kbs)
DSL (up to 1.5 Mbs)
Cable (typically up to 1.5 Mbs)
T-1 (1.5 Mbs)
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Point to Point
Frame Relay
T-3
(and so on)
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Network Security
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Physical Security of Servers
Desktop Security
Password Security
Virus Protection
Security Advisories and Updates
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Recent Example:
 http://www.pgp.com/research/covert/advisories/047.asp
Firewall
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Public versus Private Addresses (NAT)
Static Versus Dynamic Addresses (DHCP)
Port Filtering, Forwarding/Mapping
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Network
Address
Translation
The
Internet
Public IP Addresses
NAT Gateway
Private IP Addresses
(Invisible to Outside World)
Hub or Switch
Computer
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Computer
Remote Laptops
Dialup/Wireless
A Typical Logical
Diagram
Combining
LAN and WAN
ISP
1.1 Mbs
SDSL Router
Gateway Server
Plan for
Mission Hospice
of San Mateo
100 Mbs FE
Main Server
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Physical Wiring Diagram
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For More Information
A useful glossary of networking terms can be found on 3CoM’s web site:
www.3com.com/corpinfo/en_US/glossary.jsp
Another useful glossary can be found at:
www.eeng.brad.ac.uk/help/.xferfile/.glossary.html
Mark L. Miller, Ph.D.
The Miller Institute for
Learning with Technology
www.learningtech.org
[email protected]
650-598-0105
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