Training Course on Network Administration

Transcription

1 Training Course on Network Administration 03-07, March 2014 National Centre for Physics Presentation_ID 1

2 Course Outline Day-1 Exploring Networking world. Network Communication Models. OSI and TCP/IP Architecture. Application Layer Transport Layer Day-2 Network Layer IP addressing and Planning Data Link Layer Day-3 Switched Networks VLANs Routing Inter-VLAN Routing Day-4 Dynamic Routing RIP OSPF Day-5 Access Control Lists Network Address Translation Network Monitoring Presentation_ID 2

3 About Course Theoretical portion of this course is customized version of Cisco curriculum, where many different topics are added. First two days will cover the Fundamental concepts of Networking, which will be mostly theoretical. Remaining Three days will include lectures along with hand on labs to give practical experience. Keep it interactive to get maximum out of it. Presentation_ID 3

4 Exploring the Network Network Basics Presentation_ID 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 4

5 Interconnecting our Lives Networks in Our Past and Daily Lives Presentation_ID 5

6 Interconnecting our Lives Networking impacts in our daily lives Learn Communicate Work Play Presentation_ID 6

7 Converged Networks Traditional Service Networks Presentation_ID 7

8 Converged Networks Current Service Networks Presentation_ID 8

9 Reliable Network Supporting Network Architecture As networks evolve, we are discovering that there are four basic characteristics that the underlying architectures need to address in order to meet user expectations: Fault Tolerance Scalability Quality of Service (QoS) Security Presentation_ID 9

10 Reliable Network Fault Tolerance in Circuit Switched Network Presentation_ID 10

11 Reliable Network Fault Tolerance in Packet Switched Network Presentation_ID 11

12 Reliable Network Scalability Presentation_ID 12

13 Reliable Network Quality of Service (QoS) Presentation_ID 13

14 Reliable Network Network Security Presentation_ID 14

15 LANs, WANs, and Internets Components of a Network There are three categories of network components: End devices Intermediary devices Network media Presentation_ID 15

16 Network Representations The symbols used to represent the different devices and connections that make up a network. Presentation_ID 16

17 Components of a Network Network Topology Diagrams Presentation_ID 17

18 LANs and WANs Types of Networks The two most common types of network infrastructures are: Local Area Network (LAN) Wide Area Network (WAN). Other types of networks include: Metropolitan Area Network (MAN) Wireless LAN (WLAN) Storage Area Network (SAN) Presentation_ID 18

19 LANs and WANs Presentation_ID 19

20 LANs, WANs, and Internets The Internet Presentation_ID 20

21 Connecting to the Internet Connecting Businesses to the Internet Presentation_ID 21

22 Network Trends New trends Some of the top trends include: Bring Your Own Device (BYOD) Online collaboration Video Cloud computing Presentation_ID 22

23 Network Trends Bring Your Own Device (BYOD) BYOD is about end users having the freedom to use personal tools to access information and communicate across a business or campus network. Presentation_ID 23

24 Network Trends Online Collaboration and Considerations Presentation_ID 24

25 Network Trends Video Communications - Video is becoming a key requirement for effective collaboration as organizations extend across geographic and cultural boundaries. Video users now demand the ability to view any content, on any device, anywhere. Presentation_ID 25

26 Network Trends Cloud Computing. Cloud Computing - Cloud computing is the use of computing resources (hardware and software) that are delivered as a service over a network. A company uses the hardware and software in the cloud and a service fee is charged. Presentation_ID 26

27 Network Trends Data Centers - Cloud computing is possible because of data centers. A data center is a facility used to house computer systems and associated components including: Redundant data communications connections Redundant storage systems (typically uses SAN technology) Redundant or backup power supplies Environmental controls (e.g., air conditioning, fire suppression) Security devices Presentation_ID 27

28 Network Protocols and Communications Network Basics Presentation_ID 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 28

29 Protocols Network Communications Presentation_ID 29

30 Rules of Communications Establishing Rules Protocols in human communications account for the following requirements: An identified sender and receiver Common language and grammar Speed and timing of delivery Confirmation or acknowledgement requirements Common computer protocols include: Message encoding Message formatting and encapsulation Message size Message timing Message delivery options Presentation_ID 30

31 How network are designed and built? Networks are complex with many pieces of Hosts, routers, links, applications, protocols, hardware, software. Can we organize it, somehow? Let s consider a Web page request: Browser requests Web page from server Server should determine if access is privileged Reliable transfer page from server to client Physical transfer of bits from server to client Presentation_ID 31

32 Organization of air travel a series of steps ticket (purchase) baggage (check) gates (load) runway takeoff airplane routing ticket (complain) baggage (claim) gates (unload) runway landing airplane routing airplane routing Presentation_ID 32

33 Layering of airline functionality ticket (purchase) ticket (complain) ticket baggage (check) baggage (claim baggage gates (load) gates (unload) gate runway (takeoff) runway (land) takeoff/landing airplane routing airplane routing airplane routing airplane routing airplane routing departure airport intermediate air-traffic control centers arrival airport layers: each layer implements a service via its own internal-layer actions relying on services provided by layer below Presentation_ID 33

34 Reference Models Network Layered Model Presentation_ID 34

35 OSI Model Initially the OSI model was designed by the ISO to provide a framework on which to build a suite of open systems protocols. Ultimately, the speed at which the TCP/IP-based Internet was adopted, and the rate at which it expanded, caused the development and acceptance of the OSI protocol suite to lag behind. Often referred to by the number of the layer. Presentation_ID 35

36 TCP/IP Model Alternative model. The architecture of the TCP/IP protocol suite follows the structure of this model. Similar to OSI Model Presentation_ID 36

37 Peer-to-Peer Communications Hosts (all layers) Hosts (all layers) Routers Switches/NICs Repeaters, Hubs, Cables, etc. Routers Switches/NICs Repeaters, Hubs, Cables, etc. Presentation_ID 37

38 Communicating the Messages Segmentation Better approach segmentation. Multiplexing: Different conversations can be interleaved. Presentation_ID 38

39 Disadvantage of Segmentation Disadvantage added level of complexity. Analogy: 100 page letter one page at a time Separate envelopes Sequencing Presentation_ID 39

40 Data Encapsulation Application Upper-Layer Data Presentation Session PDU TCP Header Upper-Layer Data Transport Segmen IP Header Data Network Packet LLC Header MAC Header Data Data FCS FCS Data-Link Frame Physical Bits Presentation_ID 40

41 The Communication Process - Encapsulation Data Link Header IP Header TCP Header HTTP Header Data Data Link Trailer Server HTTP Data Encapsulation Process of adding control information as it passes down through the layered model. Presentation_ID 41

42 The Communication Process - Decapsulation Data Link Header IP Header TCP Header HTTP Header Data Data Link Trailer Client HTTP Data Decapsulation Process of removing control information as it passes upwards through the layered model. Presentation_ID 42

43 Devices and their layers Transceiver Hosts and servers operate at Layers 2-7; they perform the encapsulation process. Routers: Layers 1 through 3, make decisions at layer 3 Switches and NICs: Layers 1 and 2, make decisions at layer 2 Hubs and transceivers: Layer 1, no decisions to make Presentation_ID 43

44 Data Flow Through a Network Presentation_ID 44

45 Accessing Local Resources Network Address Contains information required to deliver the IP packet from the source device to the destination device. Has two parts, the network prefix and the host part. An IP packet contains two IP addresses: Source IP address - The IP address of the sending device. Destination IP address - The IP address of the receiving device. The destination IP address is used by routers to forward a packet to its destination. Presentation_ID 45

46 Accessing Local Resources Data Link Address Different role. The purpose of the data link address is to deliver the data link frame from one network interface to another network interface on the same network. IP packet encapsulated in a data link frame so it can be transmitted over the physical medium, the actual network. Ethernet LANs and wireless LANs are two examples of networks Presentation_ID 46

47 Accessing Local Resources Data Link Address The source and destination data link addresses are added: Source data link address - The physical address of the device that is sending the packet. Initially this is the NIC that is the source of the IP packet. Destination data link address - The physical address of the network interface of either: Next hop router or Network interface of the destination device Presentation_ID 47

48 Communicating on same Network Presentation_ID 48

49 Learning the MAC Address Presentation_ID 49 49

50 Accessing Remote Devices Presentation_ID 50

51 Accessing Remote Devices Presentation_ID 51 51

52 Accessing Remote Resources Using Wireshark to View Network Traffic Presentation_ID 52

53 Application Layer Presentation_ID 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 53

54 The TCP/IP Application Layer There are many TCP/IP application layer protocols and new protocols are always being developed. HTTP Hypertext Transfer Protocol DNS - Domain Name System SMTP - Simple Mail Transfer Protocol POP - Post Office Protocol IMAP - Internet Message Access Protocol FTP - File Transfer Protocol TFTP - Trivial File Transfer Protocol DHCP - Dynamic Host Configuration Protocol Presentation_ID 54

55 Two Networking Models Networked computers take on different roles or functions in relation to each other. Peer-to-Peer (P2P) network. Variations: P2P networks and P2P applications. Client / Server network: Requires central servers responding to client requests. Presentation_ID 55

56 Application Layer Protocols HTTP (WWW) We will examine HTTP in detail. DHCP (IP address resolution) FTP (file transfer) DNS (domain name resolution) SMTP ( ) SMB (file sharing) P2P (file sharing) Telnet (remote login) Presentation_ID 56

57 Reminder of encapsulation/decapsulation Data Link Header IP Header TCP Header HTTP Header Data Data Link Trailer Data Link Header IP Packet Data Link Trailer Data Link Header IP Packet Data Link Trailer Data Link Header IP Packet Data Link Trailer Data Link Header IP Header TCP Header HTTP Header Data Data Link Trailer Presentation_ID 57

58 Focus on Application Header and/or Data HTTP HTTP We will examine how the application (header) and/or data communication with each other between the client and the server. Later we will look at what roles the other layers, protocols (TCP, IP, etc.) play. Presentation_ID 58

59 HTTP (Hypertext Transfer Protocol) NCP HTTP Server HTTP Client HTTP REQUEST HTTP RESPONSE HTTP The Web s application layer protocol. Implemented in Client/ Server Model Client-Request Web objects (Browser) Server-Send objects in response to request (Web Server) RFC HTTP 1.0 RFC HTTP 1.1 Stateless Protocol Presentation_ID 59

60 HTTP (Hypertext Transfer Protocol) Web page (also called a html document) Web page consists of objects Objects (examples): HTML file JPEG image GIF image JAVA applet Audio file The base HTML file references other objects in the page. <html> <head> <title>ncp-centre of Excellence, National Centre for Physics,Islamabad,Pakistan</title> </head> <body topmargin="0" leftmargin="0" rightmargin="0" style="text-align: left"> <table border="0" cellpadding="0" style="border-collapse: collapse" bordercolor="#111111" width="99%" id="autonumber1" height="373"> <tr> <td width="79%" height="105" colspan="4"> <img border="0" src="images/banner.jpg" width="100%" height="120"></td> </tr> Presentation_ID 60

61 HTTP Request Message Some data omitted for brevity GET /index.html / HTTP/1.1 Accept-Language: en-us User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1;.NET CLR ; Media Center PC 5.0;.NET CLR ; InfoPath.1) Host: Connection: Keep-Alive HTTP Server HTTP Client Request Message Request line Header lines ASCII Text Request line: Method field GET, POST and HEAD The great majority of Requests are GETs Presentation_ID 61

62 HTTP Request Message GET /index.html/ HTTP/1.1 Accept-Language: en-us User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1;.NET CLR ; Media Center PC 5.0;.NET CLR ; InfoPath.1) Host: Connection: Keep-Alive Request Line GET - Browser/client is requesting an object /index.html/ - Browser is requesting this object in this directory (default is index.html) HTTP/1.1 - Browser implements the HTTP/1.1 (1.1 is backwards compatible with 1.0) Presentation_ID 62

63 HTTP Request Message GET /~rgraziani/ HTTP/1.1 Accept-Language: en-us User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1;.NET CLR ; Media Center PC 5.0;.NET CLR ; InfoPath.1) Host: Connection: Keep-Alive Request Line GET: - Used by browser/client to request an object. POST: - Used when user has filled out a form and sending information to the server. (Forms do not have to use POST.) - Example: words in a search engine HEAD: - Similar to a GET, but the server will responds with a HTTP message but leaves out the requested object. PUT: - Used with Web publishing tools, upload objects. DELETE: - Used with Web publishing tools, delete objects. Presentation_ID 63

64 HTTP Request Message GET /~rgraziani/ HTTP/1.1 Accept-Language: en-us User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1;.NET CLR ; Media Center PC 5.0;.NET CLR ; InfoPath.1) Host: Connection: Keep-Alive Header Lines Accept-Language:- User prefers this language of the object User-Agent: - The browser type making the request Host: - Host on which the object resides Connection: - Client/browser is telling the server to keep this TCP connection Open, known as a persistent connection. - We will talk about this later in TCP (transport layer) Presentation_ID 64 64

65 HTTP Response Message HTTP/ OK Date: Fri, 22 Feb :34:18 GMT Server: Apache/ (Red Hat) Last-Modified: Thu, 15 Nov :33:12 GMT Content-Length: Connection: close Content-Type: text/html Some data omitted for brevity <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" " <html xmlns=" HTTP Server HTTP Client 65 Presentation_ID 65

66 HTTP Response Message HTTP/ OK Date: Fri, 22 Feb :34:18 GMT Server: Apache/ (Red Hat) Last-Modified: Thu, 15 Nov :33:12 GMT Content-Length: Connection: close Content-Type: text/html <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" " <html xmlns=" Response message: Status line Header lines Entity body Presentation_ID 66

67 Telnet Telnet Telnet Server Telnet provides a standard method of emulating text-based terminal devices over the data network. 67 Presentation_ID 67

68 Telnet Telnet Telnet Server Allows a user to remotely access another device (host, router, switch). A connection using Telnet is called a Virtual Terminal (VTY) session, or connection. Telnet uses software to create a virtual device that provides the same features of a terminal session with access to the server command line interface (CLI). Telnet clients: Putty Teraterm Presentation_ID 68

69 Telnet Telnet supports user authentication, but does not encrypt data. All data exchanged during a Telnet sessions is transported as plain text. Secure Shell (SSH) protocol offers an alternate and secure method for server access. Stronger authentication Encrypts data 69 Presentation_ID 69

70 Common Application Layer Protocols SMTP and POP Presentation_ID 70

71 Everyday Application Layer Protocols SMTP and POP (Continued) Presentation_ID 71

72 DNS Domain Name System DNS allows users (software) to use domain names instead of IP addresses 72 Presentation_ID 72

73 Name Resolution Need the IP address Resolver DNS client programs used to look up DNS name information. Name Resolution The two types of queries that a DNS resolver (either a DNS client or another DNS server) can make to a DNS server are the following: Recursive queries Queries performed by Host to Local DNS Server Iterative queries Queries performed Local DNS server to other servers Presentation_ID 73 73

74 DNS Name Resolution 1 User types Step 1. The DNS resolver on the DNS client sends a recursive query to its configured Local DNS server. Requests IP address for " The DNS server for that client is responsible for resolving the name Cannot refer the DNS client to another DNS server. 74 Presentation_ID 74

75 DNS Name Resolution Step 2. Local DNS Server forwards the query to a Root DNS server. Step 3. Root DNS server Makes note of.com suffix Returns a list of IP addresses for TLD (Top Level Domain Servers) responsible for.com. 75 Presentation_ID 75

76 DNS Name Resolution Root DNS Servers There are 13 Root DNS servers (labeled A through M) TLD Servers Responsible for domains such as.com, edu, org,.net,.uk, jp, fr Network Solutions maintains TLD servers for.com Educause maintains TLD servers for.edu There are redundant servers throughout the world. Presentation_ID 76 76

77 DNS Name Resolution Step 4. The local DNS server sends query for to one of the TLD servers. Step 5. TLD Server Makes note of example.com Returns IP address for authoritative server example.com (such as dns.example.com server) Presentation_ID 77

78 DNS Name Resolution Step 6. Local DNS server sends query for directly to DNS server for example.com Step 7. example.com DNS server responds with its IP address for Presentation_ID 78

79 DNS Name Resolution 8 7 Step 8. Local DNS server sends the IP address of to the DNS client. DNS Caching When a DNS server receives a DNS reply (mapping hostname to an IP address) it can cache the information in its local memory. DNS servers discard cached information after a period of time (usually 2 days) A local DNS server can cache TLD server addresses, bypassing the root DNS servers in the query chain. Presentation_ID 79

80 DNS Name Resolution In the worst cases, you'll get a dialog box that says the domain name doesn't exist - even though you know it does. This happens because the authoritative server is slow replying to the first, and your computer gets tired of waiting so it times-out (drops the connection) or the domain name does not exist. But if you try again, there's a good chance it will work, because the authoritative server has had enough time to reply, and your name server has stored the information in its cache. Presentation_ID 80

81 nslookup nslookup Displays default DNS server for your host Can be used to query a domain name and get the IP address Presentation_ID 81 81

82 DNS Name Resolution ipconfig /displaydns After a certain amount of time, specified in the Time to Live (TTL) associated with the DNS resource record, the resolver discards the record from the cache. ipconfig /flushdns Manually deletes entries The default TTL for positive responses is 86,400 seconds (1 day). The default TTL for negative responses is 300 seconds. Presentation_ID 82 82

83 Providing IP Addressing Services Dynamic Host Configuration Protocol DHCP allows a host to obtain an IP address dynamically DHCP Information can include: IP address Subnet mask Default gateway Domain name DNS Server DHCP servers can be: Server on LAN Router Server at ISP Presentation_ID 83

84 Providing IP Addressing Services DHCP Operation Presentation_ID 84

85 DHCP Dynamic Host Configuration Protocol IP addresses and other information can be obtained: Statically Dynamically (DHCP) Presentation_ID 85

86 Providing File Sharing Services File Transfer Protocol FTP allow data transfers between a client and a server FTP client is an application that runs on a computer that is used to push and pull data from a server running an FTP daemon To successfully transfer data, FTP requires two connections between the client and the server, one for commands and replies, the other for the actual file transfer Presentation_ID 86

87 Providing File Sharing Services Server Message Block Clients establish a long term connection to servers After the connection is established, the user can access the resources on the server as if the resource is local to the client host Presentation_ID 87

88 Providing File Sharing Services Server Message Block Presentation_ID 88

89 Transport Layer Network Fundamentals Presentation_ID 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 89

90 Transport Layer Presentation_ID 90

91 Encapsulation DATA SEGMENT S.P / D.P. / S.N. / Ack # / DATA IPv / HLEN / Flag / S. IP / D. IP / PACKET FRAME DATA (SEGMENT) Frame Header DATA (PACKET) Trailer Presentation_ID 91

92 Reminder of encapsulation/decapsulation Data Link Header IP Header TCP Header HTTP Header Data Data Link Trailer Data Link Header IP Packet Data Link Trailer Data Link Header IP Packet Data Link Trailer Data Link Header IP Packet Data Link Trailer Data Link Header IP Header TCP Header HTTP Header Data Data Link Trailer Presentation_ID 92

93 Focus on Transport Layer TCP TCP Presentation_ID 93

94 Transport Layer Responsibility TCP Segment TCP Segment TCP Segment TCP Segment 1. Tracking the individual communication between applications on the source and destination hosts 2. Segmenting data for manageability and reassembling segmented data into streams of application data at the destination 3. Identifying the proper application for each communication stream Presentation_ID 94

95 Transport Layer Protocols TCP/IP uses two transport layer protocols: Transmission Control Protocol (TCP) Provides reliable delivery ensuring that all of the data arrives at the destination. Uses acknowledged delivery and other processes to ensure delivery. Makes larger demands on the network more overhead. User Datagram Protocol (UDP) Provides just the basic functions for delivery no reliability. Less overhead. TCP or UDP Presentation_ID 95

96 Introducing TCP and UDP TCP and UDP TCP UDP bit Source Port Number 16-bit Destination Port Number 32-bit Sequence Number 32 bit Acknowledgement Number 4-bit Header Length 6-bit (Reserved) U R G A C K P S H R S T S Y N F I N 16-bit Window Size 16-bit TCP Checksum 16-bit Urgent Pointer Options (if any) Data (if any) Presentation_ID 96

97 Introducing TCP and UDP Introducing TCP Transmission Control Protocol (TCP) RFC 793 Connection-oriented creating a session between source and destination Reliable delivery retransmitting lost or corrupt data Ordered data reconstruction numbering and sequencing of segments Flow control - regulating the amount of data transmitted Stateful protocol keeping track of the session Presentation_ID 97

98 Introducing TCP and UDP Introducing UDP User Datagram Protocol (UDP) RFC 768 Connectionless Unreliable delivery No ordered data reconstruction No flow control Stateless protocol Applications that use UDP: Domain Name System (DNS) Video Streaming Voice over IP (VoIP) Presentation_ID 98

99 Introducing TCP and UDP Separating Multiple Communications Port Numbers are used by TCP and UDP to differentiate between applications.. Presentation_ID 99

100 Introducing TCP and UDP TCP and UDP Port Addressing Presentation_ID 100

101 Introducing TCP and UDP TCP and UDP Port Addressing Netstat Used to examine TCP connections that are open and running on a networked host Presentation_ID 101

102 TCP Communication TCP Server Processes Presentation_ID 102

103 TCP Communication TCP Connection, Establishment and Termination Three-Way Handshake Establishes that the destination device is present on the network Verifies that the destination device has an active service and is accepting requests on the destination port number that the initiating client intends to use for the session Informs the destination device that the source client intends to establish a communication session on that port number Presentation_ID 103

104 TCP Communication TCP Three-Way Handshake Step 1 Step 1: The initiating client requests a client-toserver communication session with the server. Presentation_ID 104

105 TCP Communication TCP Three-Way Handshake Step 2 Step 2: The server acknowledges the client-toserver communication session and requests a server-to-client communication session. Presentation_ID 105

106 TCP Communication TCP Three-Way Handshake Step 3 Step 3: The initiating client acknowledges the server-to-client communication session. Presentation_ID 106

107 Protocol Data Units??? Is this correct title?? TCP Reliability Ordered Delivery Sequence numbers used to reassemble segments into original order Presentation_ID 107

108 TCP Reliability Acknowledgement and Window Size The sequence number and acknowledgement number are used together to confirm receipt. Window Size - The amount of data that a source can transmit before an acknowledgement must be received. Presentation_ID 108

109 Protocol Data Units TCP Reliability and Flow Control Data Loss and Retransmission When TCP at the source host has not received an acknowledgement after a predetermined amount of time, it will go back to the last acknowledgement number that it received and retransmit data from that point forward Flow Control Uses the window size field in the TCP header to specify the amount of data that can be transmitted before an acknowledgement must be received. Adjusts the effective rate of data transmission to the maximum flow that the network and destination device can support without loss. Manages the rate of transmission so that all data will be received and retransmissions will be minimized. Presentation_ID 109

110 Protocol Data Units TCP Flow Control Congestion Avoidance Using Dynamic Window Sizes Presentation_ID 110

111 TCP and UDP TCP Reliability - Acknowledgements TCP uses a combination of sequence numbers and acknowledgements to ensure all requested data has been received. Can be inefficient when there is loss of one or more segments Selective Acknowledgements (SACK) implementation of TCP that overcomes the inefficiency of TCP acknowledgements Presentation_ID 111

112 UDP Communication UDP Low Overhead vs. Reliability UDP Simple protocol that provides the basic transport layer function Used by applications that can tolerate small loss of data Used by applications that cannot tolerate delay Used by Domain Name System (DNS) Simple Network Management Protocol (SNMP) Dynamic Host Configuration Protocol (DHCP) Trivial File Transfer Protocol (TFTP) IP telephony or Voice over IP (VoIP) Online games Presentation_ID 112

113 UDP Communication Datagram Reassembly Presentation_ID 113

114 UDP Communication UDP Server and Client Processes UDP-based server applications are assigned wellknown or registered port numbers. UDP client process randomly selects port number from range of dynamic port numbers as the source port. Presentation_ID 114

115 TCP or UDP Applications that use TCP Presentation_ID 115

116 TCP or UDP Applications that use UDP Presentation_ID 116

117 Day 1 End Presentation_ID 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 117