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 14 15 13 12 10 11 9 8 6 7 5 4 2 3 1 0 Default 0 0 1 0 0 0 0 1 0 0 0 0 0 0 1 0 2102 4 8 2 1 4 8 2 1 4 8 2 1 4 8 2 1 Bit Decimal  This means that bits 13, 8, and 1 are on.  To ignore NVRAM the 6 th bit should be made ON  When the 6 th 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 MbpsE3 = 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. 31 Asynchronous Transfer Mode (ATM)  Communications providers saw a need for a permanent shared network technology that offered very low latency and jitter at much higher bandwidths.  ATM has data rates beyond 155 Mbps.  ATM is a technology that is capable of transferring voice, video, and data through private and public networks.  It is built on a cell-based architecture rather than on a frame-based architecture.  ATM cells are always a fixed length of 53 bytes.  The 53 byte ATM cell contains a 5 byte ATM header followed by 48 bytes of ATM payload.  Small, fixed-length cells are well suited for carrying voice and video traffic because this traffic is intolerant of delay.  Video and voice traffic do not have to wait for a larger data packet to be transmitted.  The 53 byte ATM cell is less efficient than the bigger frames and packets of Frame Relay  A typical ATM line needs almost 20% greater bandwidth than Frame Relay

32. 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.

33. 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.

34. 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.

35. 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)

36. 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.

37. 37 Max. WAN Speeds for WAN Connections WAN Type Maximum Speed Asynchronous Dial-Up56-64 Kbps X.25, ISDN – BRI128 Kbps ISDN – PRIE1 / T1 Leased Line / Frame RelayE3/T3

38. 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

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

40. 40 FlagAddressControlDataFCSFlag HDLC Supports only single protocol environments FlagAddressControlProprietaryDataFCSFlag Cisco HDLC HDLC Frame Format Cisco’s HDLC has a proprietary data field to support multiprotocol environments

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

42. 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

43. 43 Feature How It OperatesProtocol 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

44. 44 PPP Authentication Overview Two PPP authentication protocols: PAP and CHAP PPP Session Establishment 1Link Establishment Phase 2Optional Authentication Phase 3 Network-Layer Protocol Phase Dialup or Circuit-Switched Network

45. 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” Accept/Reject

46. 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 Challenge Response Accept/Reject Use “secret” known only to authenticator and peer

47. 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 ppp authentication 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

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

49. 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

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

51. 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 R1R2 PSTN/ISDN

52. 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

53. 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 R1R2 Service Provider debug ppp authentication

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

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

56. 56 •BRI and PRI are used globally for ISDN ChannelMostly Used for B Circuit-switched data (HDLC, PPP) Capacity 64 kbps D2B ISDN Access Options Signaling information D16/64 kbps 23 or 30B BRI PRI D

57. 57 Advantages of ISDN (2)  Bandwidth on Demand  adding new channels to the bundle of channels  Multiple devices  phone, fax, PC, videoconferencing system, router

58. 58 Interfaces and Devices TE1 TE2TA NT1 2W4W ISDN Ready BRI Port Analog devices: phone, Serial port After connecting to TA it becomes TE1 S/T interface U interface ISDN SwitchISDN Switch

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

60. 60 Reference Points

61. 61 LAB-ISDN E0 192.168.0.2192.168.1.2 R2 ISDN Switch BRI 192.168.1.1 R1 E0 BRI 192.168.0.1 10.0.0.110.0.0.2 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

62. 62 ISDN DDR configuration Commands CommandDescription iprouteGlobal command that configure static route or default route username name name password secret Global command that configure CHAP username and password access-listGlobal command that creates ACL’s to define a subset of traffic as interesting dialer-list 1 protocol IPGlobal command that creates a dialer list that makes all IP traffic interesting or reference to ACL for subset dialer–group 1Interface subcommand that references dialer list to define what is interesting dialer idle-timeout 100Interface subcommand that settles idle time out values dialer string numberInterface subcommand that define dial numbers int bri 0Global command that selects BRI interface

63. 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

64. 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

65. 65 Terminology Frame Relay Network R2 R1 End Device Interface Device Encapsulate Data FR Network DCE – Dedicated FR Switches, can be one or multiple Access LineTrunk 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.

66. 66 Frame Relay  Frame Relay differs from X.25 in several aspects.  Much simpler protocol that works at the data link layer, not the network layer.  Frame Relay implements no error or flow control.  The simplified handling of frames leads to reduced latency, and measures taken to avoid frame build-up at intermediate switches help reduce jitter.  Most Frame Relay connections are PVCs rather than SVCs.  Frame Relay provides permanent shared medium bandwidth connectivity that carries both voice and data traffic.

67. 67 LAB - Frame Relay 192.168.1.2/24192.168.2.2/24 R2 FR Switch S0 192.168.2.1/24 R1 E0 S0 192.168.1.1/24 192.168.3.9/29 E0 100200 192.168.3.10/29 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