What You Need to Know About IP Networking Tutorial

Transcription

1 What You Need to Know About IP Networking Tutorial Wayne M. Pecena, CPBE, CBNE Texas A&M University Office of Information Technology Educational Broadcast Services KAMU Public Broadcasting

2 "What You Need to Know About IP Networking Tutorial" Advertised Presentation Scope: There is no question that Information Technology has made a major impact in the design, operation, and support of the modern broadcast plant. As a result, the successful Broadcast Engineer must have knowledge and be proficient in many IT areas. IP Networking is the cornerstone technology of Information Technology that must be mastered in order to understand and implement virtually any Information Technology area. This presentation will examine IP Networking from a standpoint of understanding what you should know, why the networking topics are important, and suggestions on to know what you know. My Goals & Deliverables for Today: - Provide an Awareness of IP Networking Standards & Fundamentals - Provide a Basic Understanding of Ethernet Switching - Provide a Basic Understanding of IP Routing - Provide Suggested Practices to Create a Segmented Network Infrastructure Focused Upon Performance & Security 2

3 "What You Need to Know About IP Networking Tutorial Today s Outline: Introduction: IP Networking Models & Standards Data Flow Focus: Layer 1 The Physical Infrastructure Layer 2 Physical Addressing & Ethernet Switching Layer 3 Virtual Addressing & IP Routing Layer 4 TCP and UDP Transport Building a Segmented IP Network Infrastructure Takeaways, Questions, and Maybe Some Answers 3

4 Importance Of IT Knowledge! 4

5 A Sampling of IT Knowledge Applications API(s) ASP.net C++ HTML Java JavaScript PHP Lifecycle Management Quality Assurance SQL Visual Basic Visual Studio XML.NET Access Forms Interoperability Security Project Management Testing Tools Security Storage Data Centers Database ACL Antivirus Practices Authentication Digital Certs Firewall Identify Access Management Intrusion Detection Password Management Risk Management Security Tokens Incident Response Single Sign-On Virus Trogans Worms Archiving Backup Management RAID Data Recovery NAS SAN NTFS SATA SCSI Partitioning Fibre Channel Replication Storage Management LTE Defragmentation Data Center Design Server Management Power UPS Management HVAC Cooling Management Op Systems Failover Systems File System Architecture System Monitoring System Management High Availability Systems Engineering Administration DB2 Access SQL Oracle Migration Flat Files ODBC Timestamp Query Triggers Security CSV Hashing Indexing JDBC Sybase QMF Primary Keys Report Generation Cloud Computing Cloud Service Provider Software as a Service (SaaS) Service Oriented Architecture Platform as a Service (PaaS) Infrastructure As a Service (IaaS) Reliability Security Availability Business Process Management (BPM) Private / Public Hybird Clouds IP Networking 5

6 Introduction: IP Networking Models & Standards 6

7 5 Things Required To Build a Network Send Host Receive Host Message or Data to Send Between Hosts Media to Interconnect Hosts Protocol to Define How Data is Transferred Media Protocols Media Send Host DATA Receive Host A Network is a Group of Host Devices That Share a Common Addressing Scheme A Host is Any Device That Can Be Connected to That Network 7

8 The Legacy Flat Network A Single Broadcast Domain 8

9 The Hierarchical Network Organize By: Policy Regulation Security Performance / / /26 9

10 The Internet 10

11 Standards Organizations De Jure & De Facto IETF Internet Engineering Task Force The Internet Standard RFC s IEEE- Institute of Electrical & Electronic Engineers Ethernet & Wireless LAN Standards ISO International Standards Organization OSI Reference Model ITU International Telecommunications Union Global Telecommunications Standards (ie PSTN) EIA Electronic Industries Association Focused on Physical Layer Standards 11

12 IETF Internet Engineering Task Force Request for Comments RFC s The Standards Bible of the Internet Used to Explain All Aspects of IP Networking Nomenclature RFC xxxx Requirement Levels: Required Recommended Elective Limited Use Deprecated / Not Recommended 12

13 IEEE- Institute of Electrical & Electronic Engineers Project 802 Ethernet Standards: Bridging Ethernet Wireless 13

14

15 The OSI Model Open Systems Interconnection (OSI) Model Developed by the International Organization for Standardization (ISO) A Conceptual Model Abstract in Nature Modular in Structure Provides Layer Swapping Partitions Communications Function - Defines How Data Traverses From An Application to the Network Networking Focus 15

16 Open Systems Interconnection OSI Model Application Presentation Session Transport Network Data Link Physical User Application Interaction Standardizes Data Encoding/Decoding/ Compression/Encryption Tracks User Sessions Inter-Host Communications Manages End-End Connections: TCP, UDP, & Flow Control Provides Internetwork Routing (path) Provides Virtual Addressing (IP) Provides Network Access Control, Physical Address (MAC), & Error Detection Interfaces to Physical Network, Moves Bits Onto & Off Network Medium 16

17 The Protocol Data Unit Layer PDU 4 Segment Source Port Destination Port Data 3 Packet Source IP Destination IP Protocol Segment 2 Frame Destination MAC Source MAC Ether Type Packet FCS 1 Bit

18 Encapsulation Data is Encapsulated As It Travels Through the Stack From Application 18

19 Encapsulation & De-Encapsulation TCP Header Upper Level Data Upper Level Data Application Presentation Session Transport PDU Segment Application Presentation Session Transport Upper Level Data IP Header Data Network Packet Network LLC Header Data CS MAC Header Data CS Data Link Frame Data Link Physical Bits Physical 19

20 Application Application Presentation Presentation Session Session Transport Transport Network Network Network Network Data Link Data Link Data Link Data Link Data Link Data Link Data Link Data Link Physical Physical Physical Physical Physical Physical Physical Physical 20

21 TCP/IP Model or TCP/IP Stack OSI Model TCP/IP Model Application Presentation Application Session Transport Network Data Link Physical Transport Internet Network Interface TCP/IP Ethernet Focused 21

22 The Real World OSI Model RFC 2321 A Description of the usage of Nondeterministic Troubleshooting and Diagnostic Methodologies ID10T Errors Occur Here 22

23 Data Flow Focus: Layer 1 The Physical Infrastructure 23

24 Ethernet Is the Standard Today! Conceptually Based Upon ALOHA NET Developed as a Wireless Network by Norman Abramson & colleagues Developed in 1968 & Deployed at the University of Hawaii in 1971 Later Refined at Xerox PARC in 1973 to Become Ethernet Bob Metcalf & David Boggs Fathers of Ethernet 24

25 Ethernet Media Evolution Thicknet Vampire Tap Thinnet Topology Also Migrates from Bus to Star Based 25

26 Ethernet Physical Standards IEEE Standard Physical Standard Cable Type Speed Maximum Length 802.3a 10-Base-2 Coax (thin-net) 10 Mbps 185m Base-5 Coax (thick-net) 10 Mbps 500m 802.3i 10-Base-T Twisted Pair 10 Mbps 100m 802.3u 100-Base-TX Twisted Pair 100 Mbps 100m 802.3u 100-Base-T4 Twisted Pair 100 Mbps 100m 802.3u 100-Base-FX MM Fiber 100 Mbps m 802.3u 100-Base-SX MM Fiber 100 Mbps 500m 26

27 Ethernet Physical Standards continued IEEE Standard Physical Standard Cable Type Speed Maximum Length 802.3ab 1000-Base-T Twisted Pair 1 Gbps 100m 802.3z 1000-Base-SX MM Fiber 1 Gbps 500m 802.3z 1000-Base-LX MM Fiber 1 Gbps 500m 802.3z 1000-Base-LX SM Fiber 1 Gbps Several Km 802.3an 10G-Base-T Twisted Pair 10 Gbps 100m 802.3ae 10G-Base-SR MM Fiber 10 Gbps 300m 802.3ae 10G-Base-LR SM Fiber 10 Gbps Several Km and 20 Gigabit, 40 Gigabit, & 100 Gigabit Ethernet.. 27

28 Wireless Fidelity Networking Standards Ghz 2 Mbps (maximum) b 2.4 Ghz 11 Mbps a 5 Ghz 54 Mbps g 2.4 Ghz 54 Mbps n 2.4 MIMO 300 Mbps 802.ac 2.4 / 5 Ghz 450 / 1300 Mbps Frequency Bands (ISM): 2.4 Ghz Ghz 5 Ghz Ghz 28

29 Data Flow Focus: Layer 2 Physical Addressing & Ethernet Switching 29

30 Ethernet Network Physical Addressing MAC Address 6 Bytes Hexadecimal Notation - 00:12:3F:8D:4D:A7 Layer 2 Physical Address Fixed Burned-in-Address Assigned by NIC Mfg. Local in Scope Simplified Representation FF:FF:FF:FF:FF:FF 00:12:3F:8D:4D:A DATA Trailer Destination MAC Source MAC Source IP Destination IP IP Packet Ethernet Frame 30

31 The Layer 2 Ethernet Frame An Ethernet II (DIX) Frame Preamble Destination Source Type Address Address Data CRC 8 BYTES 6 BYTES 6 BYTES 2 BYTES BYTES VARIABLE 4 BYTES Invalid FRAME Lengths: < 64 BYTES = RUNT FRAME > 1518 BYTES = GIANT FRAME Note Preamble Not Used in Frame Length Calculation Destination Source Type Address Address Data CRC 64 Byte Minimum 1518 Byte Maximum Be Aware That Other Frame Types Exist! 31

32 Media Access Control (MAC) Address 48 bits Organization Unique Identifier (OUI) Mfg. Assigned 24 bits 24 bits 6 hexadecimal digits 6 hexadecimal digits A4 : 67 : 06 AB : 41 : D5 OUI A4:67:06 = Apple, Inc.

33 MAC Address Formats Always 48 Bits Expressed as Hexadecimal Can Be Represented in Several Formats: 00:A0:C9:14:C8:29 00-A0-C9-14-C A0.C914.C829 6 Bytes Byte 6 Byte 5 Byte 4 Byte 3 Byte 2 Byte 1 Organization Unique Identifier OUI Network Interface Controller NIC 33

34 Ethernet Switch Functions Learn MAC Addresses Filter Ethernet Frames Forward Ethernet Frames Flood Ethernet Frames Allow Redundancy (Avoid loops where redundant links exist) Can Provide Port Security Features

35 Managed vs Un-Managed Ethernet Switches Managed Switch User Configurable Provides Ability to Control & Monitor Host Communications Port Configuration, Security, & Monitoring VLAN Implementation Redundancy Supported (STP) QoS (Prioritization) Implementation Port Mirroring Un-Managed Switch Fixed Configuration Plug & Play Provides Basic Host Communications Cheaper 35

36 Learning a MAC Address Switch MAC Address Table Content Addressable Memory (CAM) Table A1 A2 A3 A4 MAC ADDRESS 08-3e-8e e-8e e-8e e-8e PORT A1 A2 A3 A4 08-3e-8e e-8e A Real MAC Address Table 08-3e-8e e-8e NOTE VLAN 1 is Special

37 Frame Flow Through Network P R E Destination MAC 00:00:0C:C1:00:20 Source MAC 00:00:0C:C1:00:10 T Y P E Source IP Destination IP DATA C R C 00:00:0C:C1:00: :00:0C:C1:00: :00:0C:C1:00: MAC Address Changes As Frame Passes Through the Network 00:00:0C:C1:00: HOST A 00:06:5B:01:02: :06:5B:11:22: HOST B P R E Destination MAC 00:06:5B:11:22:33 Source MAC 00:00:0C:C1:00:30 T Y P E Source IP Destination IP DATA C R C P R E Destination MAC 00:00:0C:C1:00:01 Source MAC 00:06:5B:01:02:03 T Y P E Source IP Destination IP DATA C R C 37

38 Virtual Local Area Network VLAN Allows Separation or Segmentation of Networks Across a Common Physical Media Creates Subset of Larger Network VLAN Control of Broadcast Domains Each VLAN is a Broadcast Domain Architecture Flexibility Security Static Port Based VLAN(s) Most Popular Manual Configuration Switch Port Security Features Dynamic Port Based MAC-Based VLAN(s) Assignment Based Upon MAC Address Protocol-Based VLAN(s) Assignment Based Upon Protocol 38

39 VLAN Example Access / Untagged Trunk / Tagged Switch Port Type Configuration: Cisco Terminology Access Link Member of One VLAN Only Connects to a Host Trunk Link Carries Traffic From Multiple VLANS Between Switches HP Terminology Untagged Port Member of One VLAN Only Connects to a Host Tagged Port - Carries Traffic From Multiple VLANS Between Switches 39

40 Switch Interface Configuration Switch 2 Switch 1 Switch 3 40

41 Switch Interface Configuration Interface Config: TRUNK / TAGGED Blue VLAN Green VLAN Interface Config: TRUNK / TAGGED Blue VLAN Red VLAN Green VLAN Switch 2 Switch 1 Switch 3 Access / Un-Tagged Interface Access / Un-Tagged Interface Access / Un-Tagged Interface 41

42 Adding the VLAN Tag ETHERNET FRAME PREAMBLE DESTINATION MAC ADDRESS SOURCE MAC ADDRESS TYPE DATA CRC 802.1Q ETHERNET FRAME PREAMBLE DESTINATION MAC ADDRESS SOURCE MAC ADDRESS TAG TYPE DATA CRC 4 bytes 802.1Q TAG TPID 0X8100 PRI C F I VLAN ID VLAN ID = 12 bits Yields 4,096 Possible VLAN(s) 42

43 Broadcast Domains Broadcast Domains Blue VLAN Green VLAN Red VLAN No Connectivity Exists Between Broadcast Domain, Networks, or Subnets! 43

44 VLAN Configurations Physical Separate Networks VLAN Implementation LAN #1 LAN #2 VLAN #1 VLAN #2 VLAN #1 VLAN #2 Inter-Switch Links VLAN #1 VLAN #2 VLAN #1 VLAN #2

45 Trunk Link VLAN #1 & #2 Trunk Inter-Switch Links VLAN #1 VLAN #2 VLAN #1 VLAN #2 VLAN #1 VLAN #2 Trunk Link VLAN #1 & #2 Trunk Inter-Switch Links VLAN #1 VLAN #2 VLAN #1 VLAN #2

46 Trunk Link VLAN #1 & #2 Trunk Link VLAN #1 & #2 Trunk Inter-Switch Links VLAN #1 VLAN #2 VLAN #1 VLAN #2 Internet Trunk Link VLAN #1 & #2 Trunk Link VLAN #1 & #2 Trunk Inter-Switch Links VLAN #1 VLAN #2 VLAN #1 VLAN #2

47 Data Flow Focus: Layer 3 Virtual Addressing & IP Routing 47

48 IP Network Virtual Addressing IPv4 Address 4 Bytes Doted Decimal Notation Layer 3 Logical Address Can Change Determined by Network - Assigned by User Global in Scope Simplified Representation FF:FF:FF:FF:FF:FF 00:12:3F:8D:4D:A DATA Trailer Destination MAC Source MAC Source IP Destination IP IP Packet Ethernet Frame 48

49 IP Addressing Rules Each Network MUST Have a Unique Network ID Each Host MUST Have a Unique Host ID Every IP Address MUST Have a Subnet Mask Implied for a Classful Network Explicit Stated for Classless Network An IP Address Must Be Unique Globally If Host on the Public Internet 49

50 The IPv4 Address 32 Bit Binary Address and 32 Bit Binary Mask 2 32 Yields 4,294,967,296 Addresses 32 Bits Divided Into Four (4) Octets or Bytes Expressed in Dotted Decimal Notation 32 bit IP Address Octet 1 Octet 2 Octet 3 Octet Bytes

51 2-Part IPv4 Address 32 bit IP Address Octet 1 Octet 2 Octet 3 Octet Bytes Network Address Subnet Mask Determines Host Address 51

52 IPv4 Address Classes 32 bits Class A 8 bits 8 bits 8 bits 8 bits NETWORK HOST HOST HOST Class B NETWORK NETWORK HOST HOST Class C NETWORK NETWORK NETWORK HOST Class D Multicast Class E Experimental 52

53 IPv4 Default Mask Class A 8 bits 24 bits NETWORK HOST HOST HOST Default Mask: Class B NETWORK 16 bits NETWORK HOST 16 bits HOST Default Mask: bits 8 bits Class C NETWORK NETWORK NETWORK HOST Default Mask:

54 Classful IPv4 Addressing First Octet Range Network Range Available Networks ,384 2,097,152 Available Hosts/Network 16,777,214 65, Network Bits Host Bits 24 Class 16 B Class 8 C Default Mask

55 VLSM RFC 1009 Variable Length Subnet Masking (VLSM) Host Addressing & Routing Inside a Routing Domain Allowed Classless Subnetting Mask Information is Explicit Must Be Specified Allows More Efficient Use of Address Space Taylor Address Space to Fit Network Needs Allows You to Subnet a Subnet Subnetting Borrows Host Bits to Create More Networks VLSM Allows Mask To Be Moved 55

56 VLSM Allows Mask to Be Determined on a Bit Basis Remember: Classful Addressing Specified Network/Host Boundary A B C Octet 1 Octet 2 Octet 3 Octet 4 Network Host Classless Addressing Allows Network/Host Boundary to Be Specified at an Individual Bit Network Host Octet 1 Octet 2 Octet 3 Octet 4 19 Subnet Mask Bits =

57 CIDR RFC 1517, 1518, 1519, 1520 Classless Interdomain Routing (CIDR) Class System No Longer Applies Routing Between Routing Domains Allows Supernets To Be Created Combining a Group of Class C Addresses Into a Single Block CIDR Notation (slanted notation): /19 Mask:

58 IP Address Mask Formats Classful Addressing: (Implied Mask ) VLSM Addressing: (Explicit Mask CIDR Notation : /19 Number of Mask Bits

59 IP Address Subnet Mask Example VLSM - Each IP Address Must Have a Subnet Mask to Define the Network and the Host 32 Bit Subnet Mask Expressed in Decimal as (4) 8-bit Octets using Doted Decimal Notation IP Address: / /19 or Network Host

60 IP Address Block Size Based Upon 2 n LSB 2 n

61 All Valid IPv4 Subnet Masks 61

62 Private IPv4 Address Space RFC 1918 Established Private Address Space Class A: to Class B: to Class C: to Private Address Space or 1918 Space : Private IP Address Space Is NOT Routable to the Global Internet Widely Used: Hide Host IP Address Security by Obscurity Minimize Public IP Use May Be Translated With Network Address Translation (NAT) Techniques: One-One Network Address Translation (NAT) Static & Dynamic Many-One Port Address Translation (PAT) 62

63 Network Address Translation NAT RFC 3022 Inside Network (private) Outside Network Public Address Space (Usually) RFC 1918 Addressed Hosts Gateway Router w/ NAT Services NAT Allows a Host Without a Valid Public IP Address to Communicate With a Host That Has a Public IP Address by Simply Changeing the IP Addresses as Packet Passes Through the NAT Device Why Use? Conserve Public IP Address Space Security by Obscurity (hide actual host IP address) NAT Types: Static One-to-One Translation Dynamic Pool of Public Addresses Made Available to Outbound Traffic Client Traffic NAT Overloading or Port Address Translation (PAT) Translates to a Single Public IP by Use of a Unique Port Number 63

64 Special Use Reserved IPv4 Address Space RFC /8 Network Address This Network or Wire Address /8 Private IP Address Space (RFC 1918) /8 Loopback Address /16 IETF Zero Configuration Address Space (RFC 3927) /16 Private IP Address Space (RFC 1918) /16 Private IP Address Space (RFC 1918) /4 Multicast Address Space /4 Experimental Address Space /32 Broadcast Address Yields About 3.7 Billion Useable IPv4 Addresses 64

65 The IPv4 Loop Back Address What is Special About ? Known as a Loop-Back Address Actually Any /8 Address Works OR the Range of to Useful For to Test Local IP Stack and Network Adapter 65

66 IPv6 Address Space IETF - RFC 2460 IPv6 Provides Expanded IP Address Space = 340,282,366,920,938,463,463,374,607,431,768,211,456 (three hundred forty UNDECILLION addresses) 3.4 x But, IPv6 is More Than Expanded Address Space: An Opportunity to Re-Engineer IPv4 Improved Support for Multicasting, Security, & Mobile Aps Multiple Addresses per Interface Host Auto-Configuration Capability Security Incorporated MTU Discovery Incorporated Traffic Engineering Provisions Incorporate

67 The IPv6 Address 128-Bit Address Binary Format: Subdivide Into Eight (8) 16-bit Groups: Convert Each 16-bit Group to Hexadecimal: (separate with a colon) 2607:b800:0faa:0003:2195:9887:bc48:28f1 2607:b800:faa:3:2195:9887:bc48:28f1

68 Address Summarization 128-Bit Address Represented as a 32 Hexadecimal Digits Subdivided Into Eight Groups (Chunks, Quads, Quartets) of Four Hexadecimal Digits (separated by colon) 2001:0000:0000:0000:0DB8:8000:200C:417A or 2001:0:0:0:DB8:8000:200C:417A or 2001::DB8:8000:200C:417A 68 68

69 What Happened to Version 5 or IPv5 of the Internet Protocol? IPv5 Simply Does Not Exist! Version 5 was intentionally skipped to avoid confusion, or at least to rectify it. The problem with version 5 relates to an experimental TCP/IP protocol called the Internet Stream Protocol, Version 2, originally defined in RFC This protocol was originally seen by some as being a peer of IP at the Internet Layer in the TCP/IP architecture and these packets were assigned IP version 5 to differentiate them from normal IPv4 packets. This protocol never went anywhere, but to be absolutely sure that there would be no confusion, version 5 was skipped over in favor of version 6.

70 IPv4 and IPv6 IPv4 Developed: Deployed: or 4.3 Billion Addresses More Than Anyone Could Possibly Use Address Based Assignment Unit /32 IPv6 Developed: mid 1990 s Deployed: or 340 Undecillion Addresses More Than Anyone Could Possibly Use Network Based Assignment Unit /64

71 An Ipv6 Address You Can Remember The IPv6 Loopback Address ::1 Summarized from: 0000:0000:0000:0000:0000:0000:0000:0001

72 Routing Routing is Simply the Moving Packets Between Different Networks (Subnets or Broadcast Domains) by A Routing Protocol Using a Routed Protocol by Determining the Best Route to the Destination. OSI Model Layer 3 Defined Inter-Networking Process Routing Types: Static Routing Dynamic Routing Routing Protocol Classes: Interior Gateway Protocol (IGP) Exterior Gateway Protocols (EGP) 72

73 Broadcast Domains Broadcast Domains Blue VLAN Green VLAN Red VLAN No Connectivity Exists Between Broadcast Domain, Networks, or Subnets! 73

74 Add Connectivity Between Broadcast Domains Add Router GE0 GE2 Network #1 Network #3 GE1 Network #2 FE0 Blue VLAN Green VLAN Red VLAN 74

75 Routing Types Static Routing Appropriate for Small & Simple Networks Minimal Router CPU/Memory No Routing Update Overhead Appropriate for Stable Networks Often Used in Stub Networks Human Intervention / Administration Required Yy Dynamic Routing Appropriate for Changing Topology Environments Automatically Adapts to Changes Desirable When Multiple Paths Exist More Scalable Hardware More Complex Less Configuration Error Prone 75

76 Dynamic Routing Categories Distance Vector Routing Protocol Periodic Routing Table Updates Distance Used as a Metric Neighbors Trust Neighbors Slow Convergence Link State Routing Protocol Routing Table Updates As Changes Occur Maintains Neighbor, Topology, & Shortest-Path Tables Each Router Updates From All Others Cost Used as a Metric 76

77 Routing Metrics & Administrative Distance Determines The Best Path to Target Host Cost Metrics: Hop Count The Number of Routers in a Path Bandwidth Throughput (bps) Load Traffic Flowing Through a Router Delay Network Latency (distance or congestion) Reliability Amount of Downtime of a Network Path Administrative Distance Indicates Believability of the Route Often Used When Multiple Protocols Are Used Often Used to Prefer A Certain Path When Multiple Paths Exist Routing Protocols Have Default Administrative Distances Smaller Metrics = Best Route Lower Administrative Distance = More Believed 77

78 Hop Count May Not Be The Best Metric! Ethernet 100 Mbps DS-3 45 Mbps DS-3 45 Mbps T Mbps T Mbps 78

79 The Routing Protocol Learn the route to each subnet in the internetwork (build routing table) Determine the best route (one route) Remove routes that are no longer valid Update routing table to reflect changes Perform updates quickly Prevent routing loops

80 The Routing Table Each Router Maintains It s Own Routing Table Routing Table Contents: Destination Network Cost and/or Metric Gateway or Next Hop Address Route Types: Direct Connected Remote Routes Simplified Routing Table Example Destination Network Next Hop Address Metric 80

81 Routing Table Examples Router A Router B / /30 Router C IP Configuration: mask default gateway / / /24 Router B /24 Routing Destination Table Network Static Routing Table Manually Entered Destination Network /24 Next Hop Address /30 Metric / /24 Next Hop Address /24 Metric / Router A sends Network / / /30 0 Router B sends Network /24 Dynamic Routing Table Generated by Routing Updates from All Routers 81

82 Packet Flow Through Network P R E Destination MAC 00:00:0C:C1:00:20 Source MAC 00:00:0C:C1:00:10 T Y P E Source IP Destination IP DATA C R C 00:00:0C:C1:00: :00:0C:C1:00: :00:0C:C1:00: HOST A IP Address Does Not Change As Packet Passes Through the Network (except if NAT is involved) 00:06:5B:01:02: :06:5B:11:22: :00:0C:C1:00: HOST B P R E Destination MAC 00:06:5B:11:22:33 Source MAC 00:00:0C:C1:00:30 T Y P E Source IP Destination IP DATA C R C P R E Destination MAC 00:00:0C:C1:00:01 Source MAC 00:06:5B:01:02:03 T Y P E Source IP Destination IP DATA C R C 82

83 IGP and EGP Protocols Exterior Gateway Protocol RIP IGRP EIGRP OSPF IS-IS BGP RIP IGRP EIGRP OSPF Interior Gateway Protocol Interior Gateway Protocol 83

84 Routing Protocol Selection Which One is Best? Static Routing EGP BGP Dynamic Routing IGP Distance Vector Protocol: Link State Protocol: RIP IGRP OSPF IS-IS Standards Based Proprietary Hybrid Protocol: EIGRP 84

85 Routing Protocol Choices Most Popular Interior Distance Vector Interior Link State Exterior Path Vector Classful RIP IGRP EGP Classless RIP v2 EIGRP OSPF v2 IS-IS BGP v4 IPv6 RIPng EIGRP v6 OSPF v3 IS-IS v6 BGP v4 Our Focus 85

86 Practical Routing Protocol Choices Common IGP Protocols VLSM Support RIP v2 EIGRP (Cisco) OSPF v2 Type: Distance Vector Hybird Link-State Metric: Hop Count Bandwidth/Delay Cost Administrative Distance: Hop Count Limit: None Convergence: Slow Fast Fast Updates: Full Table Every 30 Seconds Send Only Changes When Change Occurs Send Only When Change Occurs, But Refreshed Every 30m RFC Reference: RFC 1388 N/A RFC

87 What Is A Layer 3 Switch? IMHO Marketing Terminology Applied to a One Box Solution: OSI Model Defines Layer 2 Switching OSI Model Defines Layer 3 Routing A Layer 3 Switch Incorporates Both! Multilayer Switch Port Types: Switchport: Layer 2 Port MAC Addresses Learned Layer-3 Port: Routing Port Switched Virtual Interface: VLAN Virtual Interface Not for All Environments: Limited to Ethernet Ports/Interfaces Limited to OSPF and RIP Protocols 87

88 When to Route When to Switch? Router Broadcast Domain 1000-Full Full Broadcast Domain 10 Half 100 Full 1000 Full 100 Full 100 Full 1000 Full Switch 10 - Half Route to Limit a Broadcast Domain or Provide Interoperability Between Networks Collision Domain Hub Switch to Create a Zero Collision Domain 10 Half 10 Half 10 Half 100 Full Capable

89 Data Flow Focus: Layer 4 TCP and UDP Transport 89

90 TCP Basics Transmission Control Protocol RFC 675 and later v4 in RFC 793 Connection Oriented Protocol Connection Establishment Segmentation & Sequencing Acknowledgement Flow Control or Windowing Guaranteed Or Reliable Data Delivery Acknowledgment of Packet Receipt Retransmission Occurs if Packet Not Received High Overhead Requires Establishment of a Session TCP Windowing Feature Dynamic Window Sizing Slow-Start 90

91 TCP 3-Way Handshake Host 1 Host 2 Host 1 Initiates Connection to Host 2 Host 2 Responds With Acknowledgement Plus Sends It s Own Synchronization Message to Host 1 SYN SYN + ACK ACK Host 1 Sends Synchronize Message to Host 2 Host 1 Completes the 3-Way Handshake By Sending Acknowledgement to Host 2 91

92 UDP Basics User Datagram Protocol RFC 768 Connectionless Protocol Simple or Lightweight, but Inherently Unreliable Best Effort Data Delivery Low Overhead, Thus Low Latency Why Use? Required for Real-Time Applications: VOIP or Video Over IP or Voice Over IP AOIP or Audio Over IP Latency More Detrimental Than Data Loss 92

93 UDP Session Network SYN ACK SYN + ACK TCP Used to Establish UDP Session Data Data Data Data Data Time 93

94 TCP vs UDP TCP Connection Oriented Guaranteed Delivery Acknowledgments Sent Reliable, But Higher Latency Segments & Sequences Data Resends Dropped Segments Provides Flow Control Performs CRC Uses Port Numbers for Multiplexing UDP Connectionless Not Guaranteed No Acknowledgements Unreliable, But Low Latency No Sequencing No Retransmission No Flow Control Performs CRC Uses Port Numbers for Multiplexing 94

95 Building a Segmented IP Network Infrastructure 95

96 Hubs, Switches, & Routers Hub Layer 1 Device Acts as a Repeater - All Incoming Frame FWD Out Every Other Port Half-Duplex Based CSMA/CD Algorithm Controlled No Intelligence Collision & Broadcast Domain Across All Ports Switch Layer 2 Device Originally Called Forwarding - Then Bridging - Now Called Switching Full Duplex Based Intelligence Based Selectively Forwards Frame to a Port Each Port is a Collision Domain (assuming one device per port) Each Switch is Within a Broadcast Domain Router Layer 3 Device Forwards Packets Between Different Networks Creates Broadcast Domains Each Interface is a Broadcast Domain X 96

97 Design Hierarchical Networks! Organize By: Policy Regulation Security Performance Sales Production Engineering 97

98 ISP S1 S /25 FE 0 Network: Broadcast: Useable Range (126 hosts): FE 1 FE 0 FE3 FE 2 S0 S1 S2 35 Hosts Sales 17 Hosts Engineering 27 Hosts Production VLAN 1 VLAN 2 VLAN 3 98

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100 VLAN 1 Subnet Number: Subnet Mask: First IP Address: Broadcast IP Address: Last IP Address: VLAN 2 Subnet Number: Subnet Mask: First IP Address: Broadcast IP Address: Last IP Address: VLAN 3 Subnet Number: Subnet Mask: First IP Address: Broadcast IP Address: Last IP Address: What Else is Needed? 100

101 Takeaways Questions Maybe Some Answers 101

102 Takeaway Points Hierarchical or Segmented Networks Are Desirable! Network Traffic May Be Isolated Because of: Policy Regulations Security Performance VLANs Allow a Common Physical Infrastructure to Support Multiple Isolated Networks Each VLAN is an Isolated Network or Subnet and is a Broadcast Domain With a Unique IP Address Scheme Physical Addressing Provided by Layer 2 MAC Address Ethernet Switches Minimize Collision Domains Virtual Addressing Provided by Layer 3 IP Address IP Routers Create Broadcast Domains An IP Address Has 2-Parts: Network Address & Host Address The IP Address Mask Determines the Network Address Host Address Separation Remember Block Sizes When Addressing The Power of 2 n 102

103 Knowledge & Expertise Where Do You Fit? Source: Simon Wardley (2008) 103

104 There is More to Know! A Few Areas I Have Not Mentioned Today.. IP System Protocols Security QoS IP Multicast MPLS TCP/IP In More Depth Sequencing Ethernet Switching in More Depth Spanning Tree Routing in More Depth Access Control Lists ACL IPv6 In More Depth Implementation Approaches 104

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106 Thank You for Attending! Wayne M. Pecena Texas A&M University ? Questions? 106