CCNA Semester I

Unit 5 – Cabling LANs and WANS

Karl Wick SUNY Ulster

Part 1 Cabling the LAN

Common Media Types

Layer one hardware and topology can vary.

Many different types of media can carry data.

Layer 2 (Data Link) has the task of making it all work.

Data Link layer is a Universal Key to MediaMany Media for Ethernet. To layer Three, it all looks the same.

Ethernet Layer 2 and 1 Specifications Ethernet – The oldest, DEC, Intel & Xerox 802.3 – 10BaseT 802.3u (Fast Ethernet) 802.3z (Gigabit Ethernet over Fiber) 802.3ab (Gigabit Ethernet over UTP).

Note: The image in 5.1.3 scrolls right to left.

Here at Ulster

Each classroom workstation is wired with 100BaseT to a switch. (1-2 rooms per switch).

The switches connect to the backbone which is 1000Base-LX(single mode?) fiber.

Routers provide security at critical network junctions and connectivity to servers and to the internet.

Review of STP & UTP Cable Terminations

EIA568A and EIA568B

Bad and Good Connections

Cable Types - Straight

All 8 pins connect to the same pins on each end of the cable

Used for most Ethernet connections

EIA 568A or 568B, same on both ends

Crossover

A special cable cable used to connect two devices of the same type. Workstation to workstation Sometimes between other devices

EIA 568A on one end, EIA 568B on other Transmit and receive pairs are swapped

Rollover

Used to connect a workstation serial port to the console port on a router or programmable switch

Also called a console cable All pins swap end to end (1-8, 2-7, etc)

Which Cable to Use?

Every connection between computers or routers must have an odd number of swaps between the transmit and receive pairs. (Green-Green/White and Orange-Orange/White).

If a device has a plain port number [1,2,8], the device does NOT swap the pairs.

If a device has an X after the port number [1x, 2x, 24x], the device DOES swap the pairs.

Which Cable to Use?

Every connection between computers or routers must have an odd number of swaps between the transmit and receive pairs.

An even number of swaps brings the pairs back to a straight through condition.

Generally: Switches and hubs swap pairs and Routers do not.

The Usual, Bartender

Crossover Cable Required: Switch to Switch, Switch to Hub or Hub to Hub Router to Router PC to PC Router to PC

Straight Through Cable Required: Switch to Router Switch to PC or Server Hub to PC or Server

Ports on A Cisco 1900 Switch

Are these crossover or straight ports? What kind of cable connects a workstation to

these ports? What kind of cable would be used to connect this

switch to another 1900 series switch?

Repeaters and Hubs

Already covered in chapter three Types of Hubs:

Passive – Physical Connection Only. Does not require power to work.

Active – Retimes and cleans up the signal. Requires a power source.

Smart - Include a microprocessor chip and diagnostic capabilities.

Wireless

Infrared – Line of sight RF – passes obstructions (300-500 feet) Spread Spectrum for reliability and security

The frequency of the RF carrier wave varies. Frequency Hopping Spread Spectrum (FHSS). Direct Sequence Spread Spectrum (DSSS). Technical details not required here.

Bridges (Add on to unit 3) [Data flow between Hh and V]

[See 5.1.9 figure 4]

Bridging Tables Shown

Switches Micro-segment the Network

Switch Functions

Build Switching Tables Which MAC address(es) are on each port?

Switching data to the single proper port. This may occur simultaneously for several

conversations. 10 or 100 Base T (Most hubs run at only

10BaseT) VirtualLANS – Security Direct Plug and play replacement for Hub

Types of LANS

Peer to Peer

• Everyone is equal

• Each node controls its own resources

• No centralized administration

Client Server Network

Centralized resources Centralized Administration Central backup location Services:

Authentication Print Server File Server Application Server Mail Server Web Server

Part 2 Cabling WANS

Some Types of WAN Connections

ISDN PRI, ISDN Broadband, ATM, dialup modem, etc

/Coax

Serial Interface Connections

PPP HDLC Frame Relay

2400 bps to 1.544k bps (T1) or more.

ISDN BRI

Uses existing Copper Wire. Dial on Demand Dial on demand backup lines for faster links. Typically uses two 64k bps data channels

plus one 16k channel for overhead. May use only one 64k data channel and the

other channel for voice telephone. Uses PPP encoding for the data channels.

DSL and Cable

Digital Subscriber Line Uses existing phone lines WITHIN 18,000

feet of the Central Office. Data rates up to about T1 speed (1.5Mbps)

Cable uses existing coaxial lines. Speed similar to DSL but may be faster. Shared bandwidth.

Cisco Serial Connectors and Cables 60 Pin standard. 4 rows of 15 pins each. Smart Serial (mini) connector. Cables are labeled DTE or DCE DCE cable includes a clock signal to control

the speed of the link DTE cable does not include the clock signal Common carriers ALWAYS want to control

the clock. WHY? In our labs one router on each link will

provide a clock signal to the other.

CSU/DSU

channel/data service unit

Similar to a modem but for serial digital links. This unit will control the clock in most

installations. The router will not provide a clock signal to the CSU/DSU

It might provide a clock to another router on a different link.

Simple LAN

Two Hub (or Switch LAN)

x s

Two Hub LAN with Router for connectivity, security and isolation

Two Broadcast domains. A router filters traffic by destination and by rules

A two router network with a serial link

Note: The serial link may be a leased line several miles long.

Similar to Campus to BRC link.

Router Port Names

10BASE-T = Ethernet 0 or E0 AUI = Ethernet 1 or E1

Fast Ethernet = Fastethernet 0 or F0

Serial Ports = Serial 0/0 and Serial 0/1 or S0/0 and S0/1

S0/0 Means interface card #0 and port #0. The WIC can have 1 or 2 ports

ISDN Router Connections There are two types of router jacks for ISDN

connections. These are S/T and U. A U interface has an integrated NT1* An S/T interface requires an external NT1*

* ”Network terminator” - Used to connect four-wire subscriber wiring to the conventional two-wire “local loop”.

In North America, the customer typically provides the NT1, while in the rest of the world the service provider provides the NT1 device.

ISDN Cables

Caution: It is important to insert the cable running from an ISDN BRI port only to an ISDN jack or an ISDN switch.

ISDN BRI uses voltages that can seriously damage non-ISDN devices.

You cannot connect two ISDN routers back to back unless you go through a telephone company type ISDN switch.

DSL and Cable Routers

To connect a router for DSL service, use a phone cable with RJ-11 connectors. DSL works over standard telephone lines using pins 3 and 4 on a standard RJ-11 connector.

Cable Modems connect to ethernet ports on a router using a standard straight through cable.

Cisco says the modem uses a BNC jack to connect to cable. Many use standard F59 cable TV connectors.

Some routers have built in cable modems.

Programming Cisco Devices

Talk to the device through the console connection using an 8 pin rollover cable (NOT crossover), a workstation and a terminal emulator program.

Settings are 9600 Baud, No Parity, 1 stop bit and no flow control.

Do not use the AUX port. It is for a modem connection only. It will not work unless first turned on via the console port.

Hyperterminal

Is pre configured on our lab workstatons. You can find it on any Windows computer

through START, Programs, Accessories, Communications.

Other terminal emulators such as “CRT” are available.

Sample Hyperterminal Setup Screens

The name at the top was provided at the previous screen.

Fertig.