The Illustrated Network- P2 docx

IEEE 802.11 MAC Layer Protocol 100
The IEEE 802.11 Frame 102
Questions for Readers 105
Part II Core Protocols
CHAPTER 4 IPv4 and IPv6 Addressing 109
IP Addressing 112
The Network/Host Boundary 117
The IPV4 Address 118
Private IPv4 Addresses 122
Understanding IPv4 Addresses 122
The IPv6 Address 123
Features of IPv6 Addressing 124
IPv6 Address Types and Notation 125
IPv6 Address Prefi xes 126
Subnetting and Supernetting 127
Subnetting in IPv4 127
Subnetting Basics 128
CIDR and VLSM 131
IPV6 Addressing Details 135
IP Address Assignment 138
Questions for Readers 141
CHAPTER 5 Address Resolution Protocol 143
ARP and LANs 146
ARP Packets 153
Example ARP Operation 155
ARP Variations 157
Proxy ARP 157
Reverse ARP 158
ARPs on WANs 158
ARP and IPv6 159
Neighbor Discovery Protocol 160

ND Address Resolution 161
Questions for Readers 163
CHAPTER 6 IPv4 and IPv6 Headers 165
Packet Headers and Addresses 168
The IPv4 Packet Header 170
Fragmentation and IPv4 172
Fragmentation and MTU 175
Contents ix
Fragmentation and Reassembly 176
Path MTU Determination 176
A Fragmentation Example 177
Limitations of IPv4 179
The IPv6 Header Structure 179
IPv4 and IPv6 Headers Compared 182
IPv6 Header Changes 183
IPv6 and Fragmentation 184
Questions for Readers 187
CHAPTER 7 Internet Control Message Protocol 189
ICMP and Ping 192
The ICMP Message Format 196
ICMP Message Fields 197
ICMP Types and Codes 198
Sending ICMP Messages 203
When ICMP Must Be Sent 204
When ICMP Must Not Be Sent 204
Ping 204
Traceroute 205
Path MTU 206
ICMPv6 208
Basic ICMPv6 Messages 209

Neighbor Discovery and Autoconfi guration 211
Routers and Neighbor Discovery 212
Interface Addresses 212
Neighbor Solicitation and Advertisement 213
Questions for Readers 215
CHAPTER 8 Routing 217
Routers and Routing Tables 220
Hosts and Routing Tables 222
Direct and Indirect Delivery 226
Routing 229
Direct Delivery without Routing 230
Indirect Delivery and the Router 231
Questions for Readers 235
CHAPTER 9 Forwarding IP Packets 237
Router Architectures 242
Basic Router Architectures 243
Another Router Architecture 246
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Router Access 248
The Console Port 248
The Auxiliary Port 248
The Network 248
Forwarding Table Lookups 249
Dual Stacks, Tunneling, and IP
V6 251
Dual Protocol Stacks 252
Tunneling 252
Tunneling Mechanisms 255
Transition Considerations 256
Questions for Readers 257

CHAPTER 10 User Datagram Protocol 259
UDP Ports and Sockets 262
What UDP Is For 266
The UDP Header 267
IPv4 and IPv6 Notes 268
Port Numbers 269
Well-Known Ports 269
The Socket 273
UDP Operation 274
UDP Overfl ows 274
Questions for Readers 277
CHAPTER 11 Transmission Control Protocol 279
TCP and Connections 282
The TCP Header 282
TCP Mechanisms 285
Connections and the Three-Way Handshake 286
Connection Establishment 288
Data Transfer 289
Closing the Connection 291
Flow Control 292
TCP Windows 293
Flow Control and Congestion Control 294
Performance Algorithms 294
TCP and FTP 296
Questions for Readers 299
CHAPTER 12 Multiplexing and Sockets 301
Layers and Applications 301
The Socket Interface 304
Contents xi
Socket Libraries 305

TCP Stream Service Calls 306
The Socket Interface: Good or Bad? 307
The “Threat” of Raw Sockets 308
Socket Libraries 309
The Windows Socket Interface 309
TCP/IP and Windows 310
Sockets for Windows 310
Sockets on Linux 311
Questions for Readers 317
Part III Routing and Routing Protocols
CHAPTER 13 Routing and Peering 321
Network Layer Routing and Switching 324
Connection-Oriented and Connectionless Networks 325
Quality of Service 326
Host Routing Tables 328
Routing Tables and FreeBSD 329
Routing Tables and RedHat Linux 330
Routing and Windows XP 331
The Internet and the Autonomous System 332
The Internet Today 334
The Role of Routing Policies 336
Peering 338
Picking a Peer 340
Questions for Readers 343
CHAPTER 14 IGPs: RIP, OSPF, and IS–IS 345
Interior Routing Protocols 353
The Three Major IGPs 354
Routing Information Protocol 355
Distance-Vector Routing 355
Broken Links 356

Distance-Vector Consequences 357
RIPv1 358
RIPv2 359
RIPng for IPv6 362
A Note on IGRP and EIGRP 364
Open Shortest Path First 365
Link States and Shortest Paths 365
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What OSPF Can Do 366
OSPF Router Types and Areas 368
OSPF Designated Router and Backup
Designated Router 370
OSPF Packets 371
OSPFv3 for IPv6 372
Intermediate System–Intermediate System 372
The IS–IS Attraction 373
IS–IS and OSPF 373
Similarities of OSPF and IS–IS 374
Differences between OSPF and IS–IS 374
IS–IS for IPv6 376
Questions for Readers 377
CHAPTER 15 Border Gateway Protocol 379
BGP as a Routing Protocol 379
Confi guring BGP 382
The Power of Routing Policy 384
BGP and the Internet 386
EGP and the Early Internet 386
The Birth of BGP 387
BGP as a Path-Vector Protocol 388
IBPG and EBGP 389

IGP Next Hops and BGP Next Hops 390
BGP and the IGP 391
Other Types of BGP 392
BGP Attributes 393
BGP and Routing Policy 395
BGP Scaling 395
BGP Message Types 396
BGP Message Formats 397
The Open Message 397
The Update Message 397
The Notifi cation Message 399
Questions for Readers 401
CHAPTER 16 Multicast 403
A First Look at IPV4 Multicast 406
Multicast Terminology 408
Contents xiii
Dense and Sparse Multicast 410
Dense-Mode Multicast 410
Sparse-Mode Multicast 410
Multicast Notation 411
Multicast Concepts 411
Reverse-Path Forwarding 411
The RPF Table 412
Populating the RPF Table 412
Shortest-Path Tree 413
Rendezvous Point and Rendezvous-Point Shared Trees 414
Protocols for Multicast 415
Multicast Hosts and Routers 415
Multicast Group Membership Protocols 416
Multicast Routing Protocols 417

Any-Source Multicast and SSM 418
Multicast Source Discovery Protocol 419
Frames and Multicast 420
IPv4 Multicast Addressing 421
IPv6 Multicast Addressing 423
PIM-SM 425
The Resource Reservation Protocol and PGM 425
Multicast Routing Protocols 426
IPv6 Multicast 428
Questions for Readers 429
CHAPTER 17 MPLS and IP Switching 431
Converging What? 435
Fast Packet Switching 435
Frame Relay 435
Asynchronous Transfer Mode 438
Why Converge on TCP/IP? 441
MPLS 442
MPLS Terminology 446
Signaling and MPLS 447
Label Stacking 448
MPLS and VPNs 449
MPLS Tables 449
Confi guring MPLS Using Static LSPs 450
The Ingress Router 450
The Transit Routers 450
The Egress Router 451
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Traceroute and LSPs 452
Questions for Readers 455
Part IV Application Level

CHAPTER 18 Dynamic Host Confi guration Protocol 459
DHCP and Addressing 462
DHCP Server Confi guration 462
Router Relay Agent Confi guration 464
Getting Addresses on LAN2 465
Using DHCP on a Network 466
BOOTP 468
BOOTP Implementation 469
BOOTP Messages 469
BOOTP Relay Agents 471
BOOTP “Vendor-Specifi c Area” Options 471
Trivial File Transfer Protocol 472
TFTP Messages 473
TFTP Download 473
DHCP 475
DHCP Operation 475
DHCP Message Type Options 478
DHCP and Routers 479
DHCPv6 479
DHCPv6 and Router Advertisements 479
DHCPv6 Operation 480
Questions for Readers 481
CHAPTER 19 The Domain Name System 483
DNS Basics 486
The DNS Hierarchy 486
Root Name Servers 487
Root Server Operation 487
Root Server Details 489
DNS in Theory: Name Server, Database, and Resolver 489
Adding a New Host 490

Recursive and Iterative Queries 490
Delegation and Referral 491
Glue Records 493
DNS in Practice: Resource Records and
Message Formats 493
DNS Message Header 496
Contents xv
DNSSec 496
DNS Tools: nslookup, dig, and host 497
DNS in Action 498
Questions for Readers 507
CHAPTER 20 File Transfer Protocol 509
Overview 512
PORT and PASV 513
FTP and GUIs 516
FTP Basics 518
FTP Commands and Reply Codes 519
FTP Data Transfers 521
Passive and Port 524
File Transfer Types 526
When Things Go Wrong 526
FTP Commands 527
Variations on a Theme 529
A Note on NFS 530
Questions for Readers 533
CHAPTER 21 SMTP and Email 535
Architectures for Email 538
Sending Email Today 540
The Evolution of Email in Brief 544
SMTP Authentication 544

Simple Mail Transfer Protocol 545
Multipurpose Internet Mail Extensions 547
MIME Media Types 548
MIME Encoding 548
An Example of a MIME Message 549
Using POP3 to Access Email 550
Headers and Email 552
Home Offi ce Email 555
Questions for Readers 557
CHAPTER 22 Hypertext Transfer Protocol 559
HTTP in Action 562
Uniform Resources 565
URIs 565
URLs 566
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URNs 568
HTTP 569
The Evolution of HTTP 570
HTTP Model 571
HTTP Messages 572
Trailers and Dynamic Web Pages 573
HTTP Requests and Responses 573
HTTP Methods 575
HTTP Status Codes 576
HTTP Headers 576
General Headers 577
Request Headers 577
Response Headers 578
Entity Headers 579
Cookies 580

Questions for Readers 583
CHAPTER 23 Securing Sockets with SSL 585
SSL and Web Sites 585
The Lock 591
Secure Socket Layer 592
Privacy, Integrity, and Authentication 593
Privacy 593
Integrity 593
Authentication 594
Public Key Encryption 595
Pocket Calculator Encryption at the Client 595
Example 596
Pocket Calculator Decryption at the Server 597
Public Keys and Symmetrical Encryption 598
SSL as a Protocol 598
SSL Protocol Stack 599
SSL Session Establishment 599
SSL Data Transfer 601
SSL Implementation 601
SSL Issues and Problems 602
A Note on TLS 1.1 604
SSL and Certifi cates 604
Questions for Readers 605
Contents xvii
Part V Network Management
CHAPTER 24 Simple Network Management Protocol 609
SNMP Capabilities 612
The SNMP Model 616
The MIB and SMI 618
The SMI 618

The MIB 620
RMON 622
The Private MIB 622
SNMP Operation 623
SNMPv2 Enhancements 627
SNMPv3 628
Questions for Readers 629
Part VI Security
CHAPTER 25 Secure Shell (Remote Access) 633
Using SSH 633
SSH Basics 636
SSH Features 637
SSH Architecture 639
SSH Keys 640
SSH Protocol Operation 641
Transport Layer Protocol 642
Authentication Protocol 644
The Connection Protocol 645
The File Transfer Protocol 647
SSH in Action 649
Questions for Readers 657
CHAPTER 26 MPLS-Based Virtual Private Networks 659
PPTP for Privacy 662
Types of VPNs 662
Security and VPNs 664
VPNs and Protocols 665
PPTP 666
L2TP 667
PPTP and L2TP Compared 668
Types of MPLS-Based VPNs 668

Layer 3 VPNs 668
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