Networking Technology for Broadcast Engineers

Transcription

1 Engineers Part 2 March 24, 2011 Wayne M. Pecena, CPBE, 8 VSB, AMD, DRB, CBNT Texas A&M University Engineers Advertised Presentation Scope: This presentation will provide a Broadcast Focus in major Networking Topics and knowledge of Fundamentals and Principals to equip the Broadcast Engineer with a better understanding of TCP/IP addresses, Subnetting basics and Subnet Calculation tools, Gateways and the ISO Structure. It will also cover Switching & Routing protocols and fundamentals, MAC Addresses and VLAN fundamentals to provide a base knowledge upon which to build. And, an introduction to IPv6 will present this eminent major change to the whole IP addressing scheme. What Can You Expect in 2 Hours? Goals & Deliverables: Awareness of Major Networking Topics (broadcast focused) Basic Understanding of Topic Fundamentals & Principals Where to Obtain Further Knowledge 2 Engineers Part 2 1

2 Review Key Part 1 Takeaways Subnetting Review IPv6 Fundamentals a. Why IPv6 b. Addressing Concepts c. IPv4 to IPv6 Migration Strategies Agenda Part 2 Switching & Routing Fundamentals a. Switching Fundamentals b. MAC Addresses c. VLANS d. Routing Fundamentals & Routing Metrics e. Routing Protocols f. Which Routing Protocol Do I Use? QoS Basics a. Why is Quality of Service Needed? b. QoS Types c. Implementing QoS Controlling Network Traffic & Security Concerns 3 OSI Model A Layer Only Interacts With the Layer Below It A Layer Only Provides Capability for the Layer Above to Interact With It All People Seem To Need Data Processing 4 Engineers Part 2 2

3 Encapsulation 5 Ethernet Review IEEE Engineers Part 2 3

4 TCP Handshake & Windowing 7 TCP / UDP TCP RFC 793 Referred to as a Connection Oriented Protocol Guaranteed Or Reliable Data Delivery Acknowledgment of Packet Receipt Retransmission Occurs if Packet Not Received or Error Occurs High Overhead thus Slow A TCP Conversation Requires Establishment of a 2 Way Session Between Hosts UDP RFC 768 A Simple Protocol or Lightweight Low Overhead = Fast Best Effort Non Guaranteed Data Delivery Why Use? Required for Real Time Applications VoIP or Video Transmission Latency More Detrimental Than Data Loss 8 Engineers Part 2 4

5 NAT & PAT NAT Translates IP Addresses Limited IP Address Space Security Static NAT 1 to 1 Translation Hides Real Host IP Address Dynamic NAT (PAT) 1 to Many Translation PAT Always Used with NAT Allows 65,536 Inside Hosts To Be Identified by a Socket Address 9 IP Address Classes Public & Private Class A 126 Networks / 16,777,214 Hosts to PRIVATE to Class B 16,384 Networks / 65,534 Hosts to PRIVATE to Class C 2,097,152 Networks / 254 Hosts to PRIVATE to Engineers Part 2 5

6 Private vs Public IP Addresses RFC 1918 Established Private Address Space Class A: to Class B: to Class C: to Key Points: Private IP Addresses Are NOT Routable Outside the Local Network Widely Used in Home & Industry Networks May Be Translated With NAT At An Edge Router Map Private Address Space to Public Address Space 11 Subnetting What is a Subnet? Logical Subdivision of a Larger Network Why Do We Subnet? Efficient Use of IP Address Space Enhance Routing Efficiency Reduce Routing Table Size Network Management Policy and Segmentation Job Security for Network Engineers! 12 Engineers Part 2 6

7 Subnetting Basics Identifies the Boundary Between Network and Hosts Subnetting SimplyMoves the Boundary! Moves Boundary to the Right IP Address Subnetting Applies to All Classes Boundary Position Determined by the Subnet Netmask Expressed in Several Forms: Doted Decimal Notation (same as IP address) Slash Notation (also known as CIDR notation) IP Address with Netmask of OR /24 13 VLSM & CIDR VLSM RFC 1009 Variable Length hsubnet Masking (VLSM) Host Addressing & Routing Inside a Routing Domain Allowed Classless Subnetting Mask Information is Explicit Allows More Efficient Use of Address Space Allows You to Subnet a Subnet CIDR RFC 1517, 1518, 1519, 1520 Classless l Interdomain Routing (CIDR) Class System No Longer Applies Routing Between Routing Domains Class A & B IP Address Exhaustion Pressured Class C Address Space Allows Routing Tables To Be Reduced by Grouping Contiguous Class C Addresses into One Network Allows Supernets To Be Created Combining a Group of Class C Addresses Into a Single Block CIDR Notation (slanted notation): /16 14 Engineers Part 2 7

8 What Must Be Known About a Subnet IP Address and Mask Provides: First Network Address First Network Address Assignable to a Host Last Network Address Assignable to a Host Broadcast Address /24 Provides: Network Address First Network Address Assignable to a Host Last Network Address Assignable to a Host Broadcast Address Assignable Addresses 15 Subnetting Example Subnet / Default Gateway: Mask: Subnet 2 Public Internet / / Default Gateway: Mask: Subnet / Default Gateway: Mask: Engineers Part 2 8

9 Special Use Address RFC /8 Network Address /8 Private IP Address Space (RFC 1918) /8 Loopback Address /16 Private IP Address Space (RFC 1918) /16 Private IP Address Space (RFC 1918) /4 Multicast Address Space /32 Broadcast Address And many more special use cases.. 17 Ports & Sockets Ports RFC 1700 Allows Datagram Multiplexing li l i Between Applications Port Numbers Can Be Between Are Considered Reserved Can Be Registered Are Considered Dynamic or Private TCP and UDP Port Numbers Are Independent Sockets A Socket Is a Combination i of an IP Address & A Port Number Used for Client Server Application Interaction IP Address + Port Number = Socket Socket: :80 18 Engineers Part 2 9

10 IPv6 Fundamentals RFC 2460 IPv6 Provides Expanded IP Address Space = 340,282,366,920,938,463,463,374,607,431,768,211,456 (h (three hundred forty UNDECILLION addresses) 128 Bit Hexadecimal Notation 2001:0DB8:0234:AB00:0123:4567:8901:ABCD But, IPv6 is More Than Expanded Address Space: Re Engineered IPv4 Improved Support for Multicasting, Security, & Mobile Aps Host Auto Configuration Security Incorporated Traffic Engineering Provisions Multicast Incorporated IPv6 Does Not Replace IPv4 19 IPv4 and IPv6 Comparison Summary IP version IPv4 IPv6 Deployed Address Size 32 bit number 128 bit number Address Format Dotted Decimal Notation: Hexadecimal Notation: 2001:0DB8:0234:AB00:0123:4567:8901:ABCD Number of 2 32 = 4,294,967,296,, = 340,282,366,920,938,463,463,374,607,431,768,211,456,,,,,,,,,,, Addresses Engineers Part 2 10

11 IPv4 Depletion Situation Report Each RIR Received Final /8 in February 2011 IANA Free Pool of IPv4 = 0%. Each RIR Currently has IPv4 Addresses to Allocate, But Not Forever! Each /8 (Class C) block contains 16,777,216 addresses 21 IPv6 Is This Adequate Address Space? Current Global Demand: ~24 Million IP Addresses per Month IPv6 Address Space: Counting /64 subnets it would take ~ 768 Billion years to deplete Counting /48 subnets it would take ~ 11.7 Million years to deplete Engineers Part 2 11

12 IPv4 and IPv6 Comparison Internet Protocol version 4 (IPv4, or just IP ) First developed for the original Internet (ARPANET) in spring 1978 Deployed globally with growth of the Internet Total of 4 billion IP addresses available Well entrenched and used by every ISP and hosting company to connect customers to the Internet Allocated based on documented need Internet Protocol version 6 (IPv6) Design started in 1993 when IETF forecasts showed IPv4 depletion between 2010 and 2017 Completed, tested, and available lbl for production since 1999 Total of 340,282,366,920,938,463,463,374,607,431,768,211,456 IP addresses available Used and managed similar to IPv4 23 IPv6 Address Format & Notation 128-Bit Address Format Represented as a 32 Hexadecimal Digits Subdivided Into Eight Groups of Four Hexadecimal Digits (further summarization may be possible) 2001:0000:0000:0000:0DB8:8000:200C:417A or 2001:0:0:0:0DB8:8000:200C:417A or 2001::0DB8:8:200C:417A The Shortest Ipv6 Address: ::1 The Loopback Address 24 Engineers Part 2 12

13 IPv6 Address Trivia What Happened to Version 5 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 The Environment Today The Industry is Predominantly IPv4 Based Today IPv4 Demand Continues.. IPv4 Availability Pool Rapidly Decreasing IPv4 NAT Use Increasing IPv6 Must Be Adopted for Continued Growth IPv6 is NOT Backward Compatible With IPv4 IPv4 and IPv6 Must BOTH Be Maintained for Many Years to Come Dual Stack Approach My IPv4 Address: My IPv6 Address: 2002:80c2:f737::80c2:f737 My MAC Address: 80:C2:F7:37 26 Engineers Part 2 13

14 An Approach Call to Action Enterprise Networks IPv6 Enable Web, Mail, and Public Facing Application Servers Open Dialog With Your ISP Regarding IPv6 Connectivity Availability & Options Call to Action Content Providers You Must Be Reachable By New Internet Customers Provide IPv4 and IPv6 Connectivity Today If Only IPv4 Content is Provided You Reachability is Determined by Access Provider Transition Solutions IPv6 Implementation Technology Areas of Focus: Obtain IPv6 Address Space Obtain IPv6 Connectivity Native Tunneled Upgrade / Configure Operating Systems Upgrade / Configure Routers, Firewalls, DNS 28 Engineers Part 2 14

15 IPv6 Connectivity 29 World IPv6 Day June 8, Engineers Part 2 15

16 Takeaways IPv6 Awareness More Than Expanded Address Space IPv6 Address Format & Notation 128 Bit Number Hexadecimal Number Nomenclature Eight Groups of Four Hexadecimal Digits Develop Plans for IPv4 / IPv6 Especially if a Content Provider Upstream Provider IPv6 Availability? Native Tunneled IPv4 and IPv6 Will Co Exist in The Foreseeable Future 31 Switching Fundamentals Legacy Ethernet Used Hubs An Ethernet DA of sorts All Bits Go to All Ports High Collision Level Due to Shared Media (40 50% of Bandwidth Consumed by Collision Recovery) High Collision Level Yields High Latency Switches Allow Segmentation of Network Allows Dedicated Bandwidth and Point Point Communications Increased Throughput Due to Zero or Minimal Collisions Allows Full Duplex Operation Increased Security Capability Switches Selectively Forward Individual Frames from a Receiving Port to a Destination Port 32 Engineers Part 2 16

17 MAC Addresses Media Access Control MAC Address Unique Hardware Encoded Address Burned In Address Physical Address Spoofing Hexadecimal Format: 12:3A:4D:66:3A:1C or FF FF FF FF FF FF Switches Learn a Table of MAC Addresses MAC Table Maps Destination MAC Addresses to a Port 5 Basic Functions of an Ethernet Switch: Learning MAC Addresses Aging How Long is a MAC Address Maintained? Flooding Selective Forwarding Filtering 33 Switching Types Forwarding Method Store and Forward Receives the Entire Frame Then Makes Decision Drops Any Errored Frame Based Upon CRC SLOW! (but insures no frame errors) Cut Through Look Destination Address in Header of the Frame FAST! (but no error checking) Fragment Free (modified Cut Through) Known as Runt Free Switching 34 Engineers Part 2 17

18 A Simple MAC Table Example 35 VLANS IEEE 802.1Q Virtual Local Area Network VLAN Allows Separation of Network Devices Across a Common Physical Media Why Separate? Control Broadcast Domains Architecture Flexibility Security by Isolating Users Static Port Based VLAN(s) Most Common Manual Assignment Dynamic VLANS: MAC Based VLAN(s) Assignment Based Upon MAC Address Protocol Based VLAN(s) Assignment Based Upon Protocol 36 Engineers Part 2 18

19 VLAN Trunking Allows VLAN(s) to be Shared Across Multiple Devices 37 VLAN Example Switch Port Type Configuration: Access Link Member of One VLAN Only Connects to a Host Trunk Link Carries Traffic From Multiple VLANS Between Switches 38 Engineers Part 2 19

20 Routing Fundamentals Routing is Simply Moving Data From One Network to Another Network All Routers Are Aware of All Networks 39 Routing Protocols Routing is Simply the Moving of Data Across Networks OSI Model Layer 3 Process Routing Involves Two Processes: Determining the Best Path The Hard Part Actually Sending of the Data The Easy Part Static Routing Stub Routing (used when only one path exists) Dynamic Routing Path is Automatically Determined Interior Gateway Protocols (RIP, IGRP, EIGRP, OSPF) Distance Vector Link State Exterior Gateway Protocols (BGP) Hides Internal Topology of the Network 40 Engineers Part 2 20

21 Distance Vector Routing Protocols Routing by Rumor The Overall Network is Unknown, Only Directly Connected Neighbors Are Known by Each Router Routing Decision Based Upon a Distance or Metric and Direction or Vector to Describe the Next Hop 41 Link State Routing Protocols Network Topology Information is Flooded Throughout the Network Each Router Determines its Own Best Path 42 Engineers Part 2 21

22 Routing Protocols Interior Gateway Protocols Used Within the Same Autonomous System (AS) RIP RIPv2 IGRP EIGRP OSPF VLSM Support No Yes No Yes Yes Convergence Slow Slow Medium Fast Fast Configuration Easy Easy Medium Medium Hard Scalability Poor Poor Good Good Good Interoperability Yes Yes No No Yes Exterior Gateway Protocols Used Between Autonomous Systems BGP 43 A Routing Example 44 Engineers Part 2 22

23 What Is A Layer 3 Switch? One Box Solution: Layer 2 Bridging Traditionally Performed in Hardware Layer 3 Routing Traditionally Performed in Software Layer 3 Switch Performs Layer 3 Routing in Hardware Eliminates Use of VLAN(s) Each Port Can Be Assigned to a Subnet Not for All Environments Typically Found in Workgroup Environment Limited to Ethernet Limited to OSPF and RIP Protocols Information Technology for Broadcast Engineers 45 Switching vs Routing Broadcast Domain Collision Domain Collision Domain Collision Domain Router Collision Domain Broadcast Domain 46 Engineers Part 2 23

24 Takeaways Switching is a Layer 2 Process Why Switch? Breaks the Collision Domain MAC Addresses VLAN Basics & Applications VLAN Trunking Use Routing is a Layer 3 Process Why Route? Breaks the Broadcast Domain Recognize Routing Protocols Interior Gateway vs Exterior Gateway Routing Protocols Layer 3 Switching Provides A One Box Solution 47 Quality of Service QoS Why QoS? Allows Network Traffic to Be Prioritized Based Upon Application Streaming Media IP Telephony Real Time Control (automation) Mission Critical Applications Network Factors Impacting Quality: Throughput Dropped Packets Errors Latency Jitter Packet Delivery Out of Order 48 Engineers Part 2 24

25 QoS continued.. Implementing QoS VLAN Implementation Bandwidth Over Provisioning Traffic Shaping DiffServ Implementation Mark Packets According to Type of Service Assigned to Multiple Queues Queue Scheduling Algorithms: Techniques Raise or Lower Queue Priority WFQ Weighted Fair Queuing Class Based Weighted Fair Queuing WRR Weighted Round Robin HFSC Hierarchical Fair Service Curve 49 QoS continued.. QoS Implementation Architecture Packet Identification & Marking Network Element Provisioning End End Policy Management 50 Engineers Part 2 25

26 Controlling Network Traffic Traffic Shaping (packet shaping) is Generally Achieved by Delaying Packets Used to Optimize or Guarantee Performance Control Volume of Traffic Placed on A Network Segment (ingress) Traffic Classification: Sensitive Best Effort Undesired Traffic File Sharing (P2P Traffic) 51 Network Security Concerns Focused on Protecting the Network Infrastructure Common Threats: Packet Sniffers / Port Scanning IP Spoofing Denial of Service Attacks Application Layer Attacks Implementation Considerations: Know Your Enemy Cost Human Factors Understand Your Network Limit Scope of Access Don t Overlook Physical Security 52 Engineers Part 2 26

27 Network Security Tools Firewall Used to Create a Trusted Network Segment by Permitting or Denying Network Packets Types of Firewalls: Packet Filtering Stateless Statefull Application Layer Proxies NAT Detection Tools Intrusion Detection Systems (IDS) Signature Based Anomaly Based Intrusion Prevention Systems (IPS) Combine Firewall & IDS Functions 53 Takeaways QoS Basics Network Quality Factors QoS Implementation Techniques Traffic Shaping Basics Awareness of Network Security Threats Awareness of Network Security Implementation Considerations Firewall Types IDS/ IPS Use 54 Engineers Part 2 27

28 Visualizing The Internet Current IPv4 Internet Routing Table: 353,698 BGP Routes (Monday ) 55 Routing Trivia First Router as We Know is Was the Interface Message Processor IMP Developed in the Late 60 s for ARPANET First Message lo Was Sent on October 29, 1969 from UCLA to the Stanford Research Institute After Recovery From a System Crash, the Word login Was Successfully Transmitted Life Has Never Been the Same Since! 56 Engineers Part 2 28

29 Reference Sources: My Favorite Reference Texts: Ethernet: The Definitive Guide Charles Spurgeon Cisco CCNA Simplified 3 rd Edition Paul Browning Cisco IOS in a Nutshell 2 nd edition James Boney Network Maintenance & Troubleshooting 2 nd Edition Neal Allen Network Warrior Gary Donahue The Illustrated Network Walter Goralski Wireshark Network Analysis Laura Chappell Subnet Calculation Tools: calculator.com subnet calculator.html (Ipv4 and IPv6 capable) IpHONE Aps (itunes Store): IP Calc IP Calculator RFC Documents: editor.org 57 Reference Sources: RFC Documents: editor.org IPv6 References: ipv6.com/ Internet Routing Metrics: World IPv6 Day 58 Engineers Part 2 29

30 Wrap Up? Questions? Thank You for Attending! Wayne M. Pecena, CPBE, 8-VSB, AMD, DRB, CBNT Texas A&M University 59 Engineers Part 2 30