The document discusses managing Cisco IOS images and configuring WAN connections. It covers topics such as copying flash images using TFTP, resolving hostnames, password recovery, and configuring encapsulation protocols like HDLC and PPP. Examples are provided for configuring CHAP authentication between two routers connected over a serial link.

1. 1

2. 2
Cisco IOS File System and
Devices

3. 3
Managing Cisco IOS Images

4. 4
wg_ro_a#show flash
System flash directory:
File Length Name/status
1 10084696 c2500-js-l_120-3.bin
[10084760 bytes used, 6692456 available, 16777216 total]
16384K bytes of processor board System flash (Read ONLY)
Verifying Memory Image
Filenames

5. 5
Creating a Software Image
Backup

6. 6
Upgrading the Image from the
Network

7. 7
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
supply IP address of TFTP Server and file name

8. 8
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
– building a Domain Name System (DNS) server

9. 9
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
ping hostnames at a router prompt.

10. 10
Password Recovery
Normal Boot Sequence
POST
Bootstrap
IOS
Startup
Running
This setup is decided by configuration
register value

11. 11
Configuration Register
1415 13 12 1011 9 8 67 5 4 23 1 0
Default 00 1 0 00 0 1 00 0 0 00 1 0 2102
48 2 1 48 2 1 48 2 1 48 2 1
Bit
Decimal
This means that bits 13, 8, and 1 are on.
To ignore NVRAM the 6th
bit should be made ON
When the 6th
bit is turned on the value will be 2142

12. 12
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
go to ROM monitor mode

13. 13
Password Recovery
Router 2500
 o/r 0x2142
 i
Router 2600
 confreg 0x2142
>reset

14. 14

15. 15
WAN vs LAN
Distance between WAN and LAN
WAN speed is less
WAN is leased from Service provider

16. 16
Remote Access Overview
 A WAN is a data communications network covering a
relatively broad geographical area.
 A network administrator designing a remote network
must weight issues concerning users needs such as
bandwidth and cost of the variable available
technologies.

17. 17
WAN Overview
Service
Provider
 WANs connect sites
 Connection requirements vary depending on user requirements and
cost

18. 18
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".
CPE (Customer Premises
Equipment) are equipments
located at the customer’s site,
they are owned, operated and
managed by the customer.

19. 19
WAN technology/terminology
A demarcation point is
where customer premises
equipment (CPE) ends, and
local loop begins.
The local loop is the
cabling from demarcation
point to Central Office
(CO).

20. 20
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
the codes and electrical
parameters the devices
use to communicate with
each other.

21. 21
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
analog signals are returned to
their digital form, or
demodulated

22. 22
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
(HDLC)

23. 23
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
Switched
Circuit
Switched
• POTS
• ISDN
Packet Switched
• X.25
• Frame Relay
•ATM

24. 24
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
– T1 = 1.544 Mbps E1 = 2.048 Mbps
– T3 = 44.736 Mbps E3 = 34.368 Mbps

25. 25
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.
 Symmetric service provides the same capacity in both directions.

26. 26
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.
• With the upload path, there is a analogue-to-digital conversion at
the client side.

27. 27
Cable Modems (Shared
Analog)
 Cable TV provides residential premises with a coaxial cable that has a
bandwidth of 750MHz
 The bandwidth is divided into 6 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
PC via a cable box

28. 28
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
Cost is very high

29. 29
Circuit Switched Services
 Integrated Services Digital Network (ISDN)
 Historically important--first dial-up digital service
 Max. bandwidth = 128 kbps for BRI (Basic Rate
Interface)
 2 B channels @ 64kps and 1 D channel @ 16kps
 B channels are voice/data channels; D for
signaling
B
B
D

30. 30
Integrated Services Digital
Network

31. 32
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
before the end-to-end connection is established.

32. 33
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
technologies.

33. 34
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
underlying WAN technology and the communicating
equipment.

34. 35
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
Asynchronous Transfer Mode (ATM)

35. 36
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
transfer and the type of service with the available cost
that will suit you.

36. 37
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 / Frame Relay E3/T3

37. 38
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
Service
Provider

38. 39
WAN Protocols
• Point to Point - HDLC, PPP
• Multipoint - Frame Relay, X.25 and ATM
E0 S0 S0
WAN
LAN
Network
Datalink
Physical
• HDLC – Proprietary – cisco device default
• PPP - Open

39. 41
HDLC Command
Router(config-if)#encapsulation hdlc
• Enable hdlc encapsulation
• HDLC is the default encapsulation on
synchronous serial interfaces

40. 42
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
back
Link setup and control
using LCP in PPP
An Overview of PPP

41. 43
Feature How It Operates Protocol
Authentication PAP
CHAPPerform Challenge Handshake
Require a password
Compression
Compress data at source;
reproduce data at
destination
Error
Detection
Avoid frame looping
Monitor data dropped on link
Multilink Load balancing across
multiple links
Multilink
Protocol (MP)
PPP LCP Configuration Options

42. 44
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
Network

43. 45
• Passwords sent in clear text
Selecting a PPP
Authentication Protocol
Remote Router
(SantaCruz)
Central-Site Router
(HQ)
Hostname: santacruz
Password: boardwalk
username santacruz
password boardwalk
PAP
2-Way Handshake
“santacruz, boardwalk”“santacruz, boardwalk”
Accept/RejectAccept/Reject

44. 46
Selecting a PPP
Authentication Protocol
(cont.)
Remote Router
(SantaCruz)
Central-Site Router
(HQ)
Hostname: santacruz
Password: boardwalk
username santacruz
password boardwalk
CHAP
3-Way Handshake
ChallengeChallenge
ResponseResponse
Accept/RejectAccept/Reject
•Use “secret” known only to authenticator and
peer

45. 47

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








46. 48
Configuring PPP
Router(config-if)#encapsulation ppp
• Enable PPP encapsulation

47. 49
Configuring PPP
Authentication
Router(config)#hostname name
• Assigns a host name to your router
Router(config)#username name password password
• Identifies the username and password
of authenticating router

48. 50
Configuring PPP Authentication
(cont.)
Router(config-if)#ppp authentication
{chap | chap pap | pap chap | pap}
• Enables PAP and/or CHAP authentication

49. 51
Configuring CHAP Example
• hostname R1
• username R2 password cisco
• !
• int serial 0
• ip address 10.0.1.1 255.255.255.0
• encapsulation ppp
• ppp authentication CHAP
• hostname R1
• username R2 password cisco
• !
• int serial 0
• 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
R1 R2PSTN/ISDN

50. 52
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, 0 drops; input queue 0/75, 0 drops
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
38021 packets input, 5656110 bytes, 0 no buffer
Received 23488 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
38097 packets output, 2135697 bytes, 0 underruns
0 output errors, 0 collisions, 6045 interface resets
0 output buffer failures, 0 output buffers swapped out
482 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up

51. 53
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 2 len 28 from ”left"
•4d20h: Se0 CHAP: I CHALLENGE id 3 len 28 from ”right"
•4d20h: Se0 CHAP: O RESPONSE id 3 len 28 from ”left"
•4d20h: Se0 CHAP: I RESPONSE id 2 len 28 from ”right"
•4d20h: Se0 CHAP: O SUCCESS id 2 len 4
•4d20h: Se0 CHAP: I SUCCESS id 3 len 4
•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 2 len 28 from ”left"
•4d20h: Se0 CHAP: I CHALLENGE id 3 len 28 from ”right"
•4d20h: Se0 CHAP: O RESPONSE id 3 len 28 from ”left"
•4d20h: Se0 CHAP: I RESPONSE id 2 len 28 from ”right"
•4d20h: Se0 CHAP: O SUCCESS id 2 len 4
•4d20h: Se0 CHAP: I SUCCESS id 3 len 4
•4d20h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0,
changed state to up
debug ppp authentication successful CHAP output
R1 R2Service
Provider
debug ppp authentication

52. 54
What is ISDN?
Provider
network
Digital
PBX
Small office
Home office
Voice, data, video
Telecommuter
Central site

53. 55
Why ISDN?
 ISDN - Integrated Services Digital Network
 Telephone services -> Telecommunication
services
 Used for voice, data and video

54. 56
• 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 informationD 16/64 kbps
23 or 30B
BRI
PRI
D

55. 58
Interfaces and Devices
TE1
TE2 TA
NT1
2W4W
ISDN Ready
BRI Port
Analog devices:
phone, Serial port
After connecting to TA it becomes TE1
S/T interface
U interface
I
S
D
N
S
w
i
t
c
h

56. 59
Interfaces and Devices
Function Group – A set of functions implemented by a device or software
Reference Point – The interface between two function group

57. 60
Reference Points

58. 61
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 0
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 1 protocol ip permit
R1(config)#int bri 0
R1(config-if)# dialer–group 1
R1(config-if)#dialer map ip 10.0.0.2 name R2 20
R1(config-if)#no shut
R1(config-if)#dialer idle-timeout 100

59. 62
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 1 protocol IP Global command that creates a dialer list that makes all
IP traffic interesting or reference to ACL for subset
dialer–group 1 Interface subcommand that references dialer list to
define what is interesting
dialer idle-timeout 100 Interface subcommand that settles idle time out values
dialer string number Interface subcommand that define dial numbers
int bri 0 Global command that selects BRI interface

60. 63
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)
 More efficient and much faster than X.25
 Used mostly to forward LAN IP packets

61. 64
Frame Relay Basics
• FR is WAN layer2 protocol
• FR developed in 1984, its a faster packet
switching technology
• In 1990 FR consortium was developed
and extension added

62. 65
Terminology
Frame Relay Network
R2R1
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
 Frame Relay there are two encapsulation types: Cisco and IETF
 Local Management Interface (LMI) is a signaling standard used between your router and
the first Frame Relay switch i - Cisco, ANSI, and Q.933A.

63. 67
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
FRSwitch(config-if)# frame-relay route 100 int serial 1/1 200
FRSwitch(config-if)#no shut
R1
Router#config t
Router(config)#hostname R1
R1(config)# int s 0
R1(config-if)#ip address 192.168.3.9 255.255.255.248
R1(config-if)#enacapsulation frame-relay
R1(config-if)# frame-relay intf-type DTE
R1(config-if)# frame-relay interface-dlci 100
R1(config-if-dlci)# exit
R1(config-if)#framerelay map ip 192.168.3.10 100
R1(config-if)#no shut