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
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.
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
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
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
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
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
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
