CCNA

 High-Level Data Link Control Protocol (HDLC).  X.25 / Link Access Procedure Balanced (LAPB)[r]

wg_ro_a#show flash

System flash directory: File Length Name/status

10084696 c2500-js-l_120-3.bin

[10084760 bytes used, 6692456 available, 16777216 total] 16384K bytes of processor board System flash (Read ONLY)

LAB

Install TFTP server on a virtual machine Connect the machine to a Router

To see the content of Flash file #show Flash

To copy flash

#Copy flash tftp

supply IP address of TFTP Server and file name

To copy running-configuration #copy running-config tftp

Resolving Host Names

 To use a hostname rather than an IP address to

connect to a remote device

 Two ways to resolve hostnames to IP addresses

– building a host table on each router

Resolving Host Names

 Building a host table

 ip host host_name ip_address

R1(config)#ip host com1 10.0.0.1 R1(config)#ip host com2 10.0.0.2

 To view table

R1#show hosts

 To verify that the host table resolves names, try

Password Recovery

Normal Boot Sequence

POST

Bootstrap IOS

Startup

Running

Configuration Register

14

15 13 1211 10 9 8 7 6 5 4 3 2 1 0

Default 0 0 1 0 0 0 0 1 0 0 0 0 0 0 1 0 2102 4

8 2 1 8 4 2 1 8 4 2 1 8 4 2 1

Bit

Decimal

This means that bits 13, 8, and are on

To ignore NVRAM the 6th bit should be made ON

Password Recovery

Show version will give configuration register

value

Password is stored in NVRAM

To by pass NVRAM during boot sequence we

need to change the configuration register value

To change the CR values press Ctr+Break and

Password Recovery

Router 2500

 o/r 0x2142

 i

Router 2600

 confreg 0x2142

WAN vs LAN

Distance between WAN and LAN

WAN speed is less

Remote Access Overview

 A WAN is a data communications network covering a

relatively broad geographical area

 A network administrator designing a remote network

WAN Overview

Service Provider

 WANs connect sites

 Connection requirements vary depending on user requirements and

WAN technology/terminology  Devices on the subscriber premises are called customer premises equipment (CPE).  The subscriber owns the CPE or leases the CPE from the service provider

 A copper or fiber cable connects the CPE to the service provider’s nearest exchange or central

office (CO) A central office (CO) is sometimes referred to as a point of presence (POP)

 This cabling is often called the local loop, or "last-mile".

WAN technology/terminology

A demarcation point is where customer premises equipment (CPE) ends, and local loop begins.

WAN technology/terminology

 Devices that put data on the local loop are called data communications

equipment (DCE).

 The customer devices that pass the data to the DCE are called data

terminal equipment (DTE).

 The DCE primarily provides an interface for the DTE into the communication

link on the WAN cloud

The DTE/DCE interface

uses various physical layer protocols, such as V.35

These protocols establish

WAN Devices

Modems transmit data over

voice-grade telephone lines by modulating and demodulating the signal

The digital signals are

superimposed on an analog voice signal that is modulated for transmission

The modulated signal can be

heard as a series of whistles by turning on the internal modem speaker

At the receiving end the

WANs - Data Link Encapsulation

 The data link layer protocols define how data is encapsulated for transmission to

remote sites, and the mechanisms for transferring the resulting frames

 A variety of different technologies are used, such as ISDN, Frame Relay or

Asynchronous Transfer Mode (ATM)

 These protocols use the same basic framing mechanism, high-level data link control

WAN Technologies Overview

 Covers a relative broad area  Use transmission facilities

leased from service provider

 Carries different traffic

(voice, video and data)

Dedicated

• T1, E1, T3, E3 • DSL

• SONET

Analog

• Dial-up modems • Cable modems • Wireless Switche d Circuit Switched • POTS • ISDN Packet Switched

• X.25

Dedicated Digital Services

Dedicated Digital Services provide

full-time connectivity through a point-to-point link

T series in U.S and E series in

Europe

Uses time division multiplexing and

assign time slots for transmissions

Digital Subscriber Lines

 Digital Subscriber Line (DSL) technology is a broadband technology

that uses existing twisted-pair telephone lines to transport high-bandwidth data to service subscribers

 The two basic types of DSL technologies are asymmetric (ADSL)

and symmetric (SDSL)

 All forms of DSL service are categorized as ADSL or SDSL and there

are several varieties of each type

 Asymmetric service provides higher download or downstream

bandwidth to the user than upload bandwidth

Analog Services

• Dial-up Modems (switched analog)

• Standard that can provides 56 kbps download speed and 33.6 kbps upload speed

• With the download path, there is a digital-to-analogue conversion at the client side

Cable Modems (Shared Analog)

 Cable TV provides residential premises with a coaxial cable that has a

bandwidth of 750MHz

 The bandwidth is divided into MHz band using FDM for each TV channel  A "Cable Modem" is a device that allows high-speed data access (Internet)

via cable TV network

 A cable modem will typically have two connections because a splitter delivers

the TV bands to TV set and the internet access bands to PC via a cable box

 The splitter delivers the TV bands to TV set and the internet access bands to

Wireless

 Terrestrial

Bandwidths typically in the 11 Mbps range

Cost is relatively low

Line-of-sight is usually required

Usage is moderate

 Satellite

Can serve mobile users and remote users

Usage is widespread

Circuit Switched Services

 Integrated Services Digital Network (ISDN)

 Historically important first dial-up digital service  Max bandwidth = 128 kbps for BRI (Basic Rate

Interface)

 B channels @ 64kps and D channel @ 16kps  B channels are voice/data channels; D for signaling

WAN Connection Types

 Leased lines

It is a pre-established WAN communications path

from the CPE, through the DCE switch, to the CPE of the remote site, allowing DTE networks to communicate at any time with no setup procedures before transmitting data

 Circuit switching

Sets up line like a phone call No data can transfer

WAN Connection Types

• Packet switching

WAN switching method that allows you to share

bandwidth with other companies to save money As long as you are not constantly transmitting data and are instead using bursty data transfers, packet switching can save you a lot of money

However, if you have constant data transfers, then

you will need to get a leased line

Frame Relay and X.25 are packet switching

Defining WAN Encapsulation Protocols

 Each WAN connection uses an encapsulation protocol to

encapsulate traffic while it crossing the WAN link

 The choice of the encapsulation protocol depends on the

Defining WAN Encapsulation Protocols

 Typical WAN encapsulation types include the following:

Point-to-Point Protocol (PPP)

Serial Line Internet Protocol (SLIP)

High-Level Data Link Control Protocol (HDLC)

X.25 / Link Access Procedure Balanced (LAPB)

Frame Relay

Determining the WAN Type to Use  Availability

Each type of service may be available in certain

geographical areas

 Bandwidth

Determining usage over the WAN is important to

evaluate the most cost-effective WAN service

 Cost

Making a compromise between the traffic you need to

Max WAN Speeds for WAN Connections

WAN Type Maximum Speed

Asynchronous Dial-Up 56-64 Kbps

X.25, ISDN – BRI 128 Kbps

ISDN – PRI E1 / T1

Leased Line

Circuit-switched

PPP, SLIP, HDLC HDLC, PPP, SLIP

Packet-switched

X.25, Frame Relay, ATM

Typical WAN Encapsulation Protocols: Layer 2

Telephone Company

WAN Protocols

• Point to Point - HDLC, PPP

• Multipoint - Frame Relay, X.25 and ATM

E0 S0

S0

WAN LAN

Network Datalink Physical

HDLC Command

Router(config-if)#encapsulation hdlc • Enable hdlc encapsulation

PPP Encapsulation

PPP is open standard

HDLC is only for encapsulation

PPP provides encapsulation and authentication PPP is made up of LCP and NCP

LCP is for link control and NCP for multiple protocol support and call

Link setup and control using LCP in PPP

Feature How It Operates Protocol

Authentication PAP

CHAP Perform Challenge Handshake

Require a password

Compression Compress data at source; reproduce data at destination

Error

Detection Avoid frame loopingMonitor data dropped on link Multilink Load balancing across

multiple links Multilink Protocol (MP)

PPP Authentication Overview

Two PPP authentication protocols: PAP and CHAP

PPP Session Establishment

1 Link Establishment Phase

2 Optional Authentication Phase

3 Network-Layer Protocol Phase

Dialup or Circuit-Switched

• Passwords sent in clear text

Selecting a PPP

Authentication Protocol Remote Router

(SantaCruz) Central-Site Router (HQ)

Hostname: santacruz

Password: boardwalk username santacruzpassword boardwalk

PAP

2-Way Handshake

“santacruz, boardwalk”

“santacruz, boardwalk”

Accept/Reject

Selecting a PPP Authentication Protocol (cont.)

Remote Router

(SantaCruz) Central-Site Router (HQ)

Hostname: santacruz

Password: boardwalk username santacruzpassword boardwalk

CHAP 3-Way Handshake Challenge Challenge Response Response Accept/Reject Accept/Reject

•Use “secret” known only to authenticator and



Configuring PPP and Authentication Overview

Service Provider

Verify who you are.

Router to Be Authenticated

(The router that initiated the call.)

ppp encapsulation hostname

username / password

Authenticating Router

(The router that received the call.)

ppp encapsulation hostname

username / password ppp authentication Enabling PPP

Enabling PPP Authentication

Enabling PPP

Enabling PPP Authentication

Configuring PPP

Router(config-if)#encapsulation ppp

Configuring PPP Authentication

Router(config)#hostname name

• Assigns a host name to your router

Router(config)#username name password password

Configuring PPP Authentication (cont.)

Router(config-if)#ppp authentication {chap | chap pap | pap chap | pap}

Configuring CHAP Example

• hostname R1

• username R2 password cisco • !

• int serial

• ip address 10.0.1.1 255.255.255.0 • encapsulation ppp

• ppp authentication CHAP • hostname R1

• username R2 password cisco • !

• int serial

• ip address 10.0.1.1 255.255.255.0 • encapsulation ppp

• ppp authentication CHAP

hostname R2

username R1 password cisco !

int serial 0

ip address 10.0.1.2 255.255.255.0 encapsulation ppp

ppp authentication CHAP hostname R2

username R1 password cisco !

int serial 0

ip address 10.0.1.2 255.255.255.0 encapsulation ppp

ppp authentication CHAP

Verifying HDLC and PPP Encapsulation Configuration

Router#show interface s0

Serial0 is up, line protocol is up Hardware is HD64570

Internet address is 10.140.1.2/24

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation PPP, loopback not set, keepalive set (10 sec)

LCP Open

Open: IPCP, CDPCP

Last input 00:00:05, output 00:00:05, output hang never Last clearing of "show interface" counters never

Queueing strategy: fifo

Output queue 0/40, drops; input queue 0/75, drops minute input rate bits/sec, packets/sec

minute output rate bits/sec, packets/sec 38021 packets input, 5656110 bytes, no buffer

Received 23488 broadcasts, runts, giants, throttles

input errors, CRC, frame, overrun, ignored, abort 38097 packets output, 2135697 bytes, underruns

Verifying PPP Authentication with the

debug ppp authentication Command

•4d20h: %LINK-3-UPDOWN: Interface Serial0, changed state to up •4d20h: Se0 PPP: Treating connection as a dedicated line

•4d20h: Se0 PPP: Phase is AUTHENTICATING, by both •4d20h: Se0 CHAP: O CHALLENGE id len 28 from ”left" •4d20h: Se0 CHAP: I CHALLENGE id len 28 from ”right" •4d20h: Se0 CHAP: O RESPONSE id len 28 from ”left" •4d20h: Se0 CHAP: I RESPONSE id len 28 from ”right" •4d20h: Se0 CHAP: O SUCCESS id len

•4d20h: Se0 CHAP: I SUCCESS id len

•4d20h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to up

•4d20h: %LINK-3-UPDOWN: Interface Serial0, changed state to up •4d20h: Se0 PPP: Treating connection as a dedicated line

•4d20h: Se0 PPP: Phase is AUTHENTICATING, by both •4d20h: Se0 CHAP: O CHALLENGE id len 28 from ”left" •4d20h: Se0 CHAP: I CHALLENGE id len 28 from ”right" •4d20h: Se0 CHAP: O RESPONSE id len 28 from ”left" •4d20h: Se0 CHAP: I RESPONSE id len 28 from ”right" •4d20h: Se0 CHAP: O SUCCESS id len

•4d20h: Se0 CHAP: I SUCCESS id len

•4d20h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to up

R1 Service R2

Provider

What is ISDN?

Provider network Digital

PBX

Small office

Home office

Voice, data, video

Telecommuter

Why ISDN?

 ISDN - Integrated Services Digital Network  Telephone services -> Telecommunication

services

•BRI and PRI are used globally for ISDN

Channel Mostly Used for

B Circuit-switched data (HDLC, PPP) Capacity

64 kbps

D 2B

ISDN Access Options

Signaling information D 16/64 kbps

23 or 30B

BRI

PRI

Interfaces and Devices TE1 TE2 TA NT1 2W 4W ISDN Ready BRI Port

Interfaces and Devices

LAB-ISDN E0 192.168.0.2 192.168.1.2 R2 ISDN Switch BRI 192.168.1.1 R1 E0 BRI

192.168.0.1 10.0.0.1 10.0.0.2

Router(config)#hostname R1

R1(config)#username R2 password cisco R1(config-if)#int bri

R1(config-if)# ip address 10.0.0.1 255.0.0.0 R1(config-if)#enacapsulation ppp

R1(config-if)#PPP authentication CHAP R1(config-if)#no shut

Static Routes or default route

R1(config)#ip route 0.0.0.0 0.0.0.0 10.0.0.2 R1(config)#isdn switch-type basic-net3

Access List

R1(config)#dialer-list protocol ip permit R1(config)#int bri

R1(config-if)# dialer–group

R1(config-if)#dialer map ip 10.0.0.2 name R2 20 R1(config-if)#no shut

ISDN DDR configuration Commands

Command Description

iproute Global command that configure static route or default route

username name name password

secret Global command that configure CHAP username and password access-list Global command that creates ACL’s to define a subset

of traffic as interesting

dialer-list protocol IP Global command that creates a dialer list that makes all IP traffic interesting or reference to ACL for subset

dialer–group Interface subcommand that references dialer list to define what is interesting

Packet Switched Services

 X.25 (Connection-oriented)

 Reliable X.25 has been extensively debugged and is now very stable literally no

errors in modern X.25 networks

 Store & Forward Since X.25 stores the whole frame to error check it before

forwarding it on to the destination, it has an inherent delay (unlike Frame Relay) and requires large, expensive memory buffering capabilities

 Frame Relay (Connectionless)

Frame Relay Basics

• FR is WAN layer2 protocol

• FR developed in 1984, its a faster packet switching technology

Terminology

Frame Relay Network

R2 R1

End Device Interface Device

Encapsulate Data

FR Network

DCE – Dedicated FR Switches, can be one or multiple

Access Line Trunk Line

Virtual Circuit – an end to end connection between interface device - PVC or SVC

 Data Link connection Identifiers (DLCI) number is the identification for VC, 16-1007  Committed Information Rate or CIR - agreed-upon bandwidth

LAB - Frame Relay 192.168.1.2/24 192.168.2.2/24 R2 FR Switch S0 192.168.2.1/24 R1 E0 S0 192.168.1.1/24 192.168.3.9/29 E0 100 200 192.168.3.10/29 DCE DCE

Frame Relay Switch Router#config t

Router(config)#hostname FRSwitch FRSwitch(config)# frame-relay switching FRSwitch(config)# int s 1/0

FRSwitch(config-if)#enacapsulation frame-relay FRSwitch(config-if)# frame-relay intf-type DCE FRSwitch(config-if)# clock rate 64000

R1

Router#config t

Router(config)#hostname R1 R1(config)# int s

R1(config-if)#ip address 192.168.3.9 255.255.255.248 R1(config-if)#enacapsulation frame-relay