Understanding the network.pdf - Back to Home

More documents

Recommendations

Info

Because the hub is effectively the backbone, there is no backbone cabling specification. Instead, hubs can be linked together using a special crossover cable. The pinout is illustrated in Figure 4.13. NOTE Figure 4.13. Ethernet 10Base-T station-to-hub interconnect and hub-to-hub crossover cable. As an alternative to using a crossover cable, certain hub manufactures provide an MDI/MDI-X port. This port is wired with a switch that can change the pin signals so the port can behave as a crossover or straight-through port. This is a nice feature as it eliminates the need for the crossover cable. It is not available on multiport bridges (or switches), however, which follow the same device interconnection scheme. A 10Base-T hub-to-hub crossover link has the same maximum distance (100m) as a station-to-hub interconnection. In addition to the maximum distance between hubs, no end-station can be separated by more than four hubs connected tougher by five 10Base-T cable segments for a total cable distance of 500m. It is possible to have more than one hub connected to an end-station (see Figure 4.14).
Figure 4.14. 10Base-T hub-to-hub interconnection using 10Base-T cabling. To provide for greater network distance, it is common to use a 10Base-5 for backbone cabling. This allows for longer distances between hubs and eliminates the hub cascading limitation by forcing the 10Base-5 backbone to provide the interconnection link between 10Base-T hubs. Most manufacturers provide an AUI or BNC interface on 10Base-T hubs just for this purpose. For longer distances beyond 500M, 10Base-FL (which can support link distances up to 2,000m) can be used. Figure 4.15 illustrates a 10Base-5 backbone with 10Base-T hubs.
Page 2 and 3:
Understanding the Network A Practic
Page 4 and 5:
IOS Authentication and Accounting S
Page 6 and 7:
About the Reviewers These reviewers
Page 8 and 9:
Tell Us What You Think As the reade
Page 10 and 11:
mostly dealt with interconnecting m
Page 12 and 13:
• A short introduction to SNMP Ap
Page 14 and 15:
In theory, a computer network can o
Page 16 and 17:
Coaxial cable has a single solid co
Page 18 and 19:
• Radio transmission—It is achi
Page 20 and 21:
• Baseband transmission applies t
Page 22 and 23:
Ring Topology Figure 1.3. The bus t
Page 24 and 25:
Packets and frames are often used a
Page 26 and 27:
Asynchronous transmission involves
Page 28 and 29:
Figure 1.6. Collision handling unde
Page 30 and 31:
In a ring topology, a token is pass
Page 32 and 33:
Repeaters The repeater was introduc
Page 34 and 35:
the network. If your 50-node networ
Page 36 and 37:
Figure 1.12. A collection of nodes
Page 38 and 39:
their destination, type, and conten
Page 40 and 41:
shop, you are using Novell's Direct
Page 42 and 43:
Figure 1.14. The OSI and Internet r
Page 44 and 45:
Layer 7: Application This layer pro
Page 46 and 47:
end-to-end, sequenced data delivery
Page 48 and 49:
outer, the delivery path might be d
Page 50 and 51:
and network transport is a very imp
Page 52 and 53:
Figure 1.16. The "bottom up" commun
Page 54 and 55:
Chapter 2. The Networker's Guide to
Page 56 and 57:
Internet Society, a nonprofit organ
Page 58 and 59:
• First, it performs translations
Page 60 and 61:
Figure 2.2. The IP header. • Vers
Page 62 and 63:
To assist in the reassembly process
Page 64 and 65:
Figure 2.3. IP address classes comp
Page 66 and 67:
taking the natural mask of the addr
Page 68 and 69:
Classful Subnetting Examples The im
Page 70 and 71:
21 2,000 8,000 255.255.248.0 22 1,0
Page 72 and 73:
classful-based address space model.
Page 74 and 75:
Table 2.6. Classless Network Addres
Page 76 and 77:
NOTE Because CIDR is used for addre
Page 78 and 79:
will connect in the future, it is b
Page 80 and 81:
Routers are also called intermediat
Page 82 and 83:
IP datagrams for which the local ho
Page 84 and 85:
1. The Layer 3 to Layer 2 address m
Page 86 and 87:
3. Router B—Router B receives the
Page 88 and 89:
connected networks. Figure 2.11 ill
Page 90 and 91:
Figure 2.12. A simple regional (ISP
Page 92 and 93:
gw1, gw2, gw4 3 gw1, gw3, gw4 3 gw1
Page 94 and 95:
Dynamic routing might not be requir
Page 96 and 97:
The transport layer as a whole repr
Page 98 and 99:
window to reflect changes in the pa
Page 100 and 101:
The TCP Header The TCP header provi
Page 102 and 103:
53 DNS (Domain Name Service) 67 BOO
Page 104 and 105:
SNMP Simple Network Management Prot
Page 106 and 107:
uses both TCP and UDP for service d
Page 108 and 109:
RFC 974 Mail routing and the domain
Page 110 and 111:
Figure 3.1. Physical versus logical
Page 112 and 113:
Figure 3.2. The AppleTalk protocol
Page 114 and 115:
AppleTalk Address Resolution Protoc
Page 116 and 117:
of 400 microseconds, in addition to
Page 118 and 119:
Along with the SAP, there is a 5-by
Page 120 and 121:
delivery is a best-effort delivery
Page 122 and 123:
• DDP checksum (long header only)
Page 124 and 125:
eachable within the internetwork. T
Page 126 and 127:
information from the router's other
Page 129 and 130:
AppleTalk Update Based Routing Prot
Page 131 and 132:
• type is the service classificat
Page 133 and 134:
application layers. AppleTalk has n
Page 135 and 136:
Figure 3.10. ZIP message formats. E
Page 137 and 138: Printer Access Protocol Printer Acc
Page 139 and 140: Figure 3.11. Novell (IPX) protocol
Page 141 and 142: The other nodes on the network that
Page 143 and 144: Figure 3.13. IPX datagram format.
Page 145 and 146: the cumulative information gleaned
Page 147 and 148: • Hop Count is the number of rout
Page 149 and 150: Upper Layer Protocols IPX is used t
Page 151 and 152: Msg.Add.Name Adds a unique name to
Page 153 and 154: Related RFCs RFC 1001 RFC 1002 RFC
Page 155 and 156: service enhancement or replacement
Page 157 and 158: Figure 4.1. The LLC interfaces in r
Page 159 and 160: it does not provide for error recov
Page 161 and 162: and smooth pattern flow enables MTL
Page 163 and 164: cabling, backbone length 800m Categ
Page 165 and 166: combination of light refraction and
Page 167 and 168: NOTE Cladding is the glass "shell"
Page 169 and 170: Ethernet The original Ethernet prot
Page 171 and 172: UTP telephone cabling infrastructur
Page 173 and 174: Since the introduction of the IEEE
Page 175 and 176: In the event that two Ethernet end-
Page 177 and 178: The 802.3 frame type used in Figure
Page 179 and 180: • Frame check sequence (4 bytes)
Page 181 and 182: • Physical layer signaling (PLS)
Page 183 and 184: cable segment length (for coaxial s
Page 185 and 186: transmission medium using BNC (Brit
Page 187: Figure 4.12. A basic 3-cable 10Base
Page 191 and 192: Figure 4.16. 10Base-T in a consulta
Page 193 and 194: • Support for full-duplex operati
Page 195 and 196: mechanisms, in terms of encoding an
Page 197 and 198: etween different PHY encoding imple
Page 199 and 200: 100Base Ethernet) is based on the p
Page 201 and 202: The Gigabit PHY The Gigabit PHY con
Page 203 and 204: CSMA/CD is sensitive to operating r
Page 205 and 206: The main advantage of using FDR ove
Page 207 and 208: have to transmit against the priori
Page 209 and 210: • Ring timing maintenance—The A
Page 211 and 212: check the lobe cable. If the lobe t
Page 213 and 214: Token Ring addresses are expressed
Page 215 and 216: • Report Active Monitor Error (RA
Page 217 and 218: they first join the ring or in the
Page 219 and 220: Figure 4.22. The IBM type 1 MIC con
Page 221 and 222: FDDI Work on the Fiber Distributed
Page 223 and 224: However, all this comes at a cost,
Page 225 and 226: Figure 4.25. FDDI MAC data frame an
Page 227 and 228: topologies needed for the transmiss
Page 229 and 230: Chapter 5. WAN Internetworking Tech
Page 231 and 232: Placing a Call The functional model
Page 233 and 234: LATAs to provide local exchange ser
Page 235 and 236: The PSTN was originally designed fo
Page 237 and 238: sampling rate is 8,000 times per se
Page 239 and 240:
Figure 5.1. A multiplexer from a lo
Page 241 and 242:
Table 5.1. The American (DS) and In
Page 243 and 244:
The M24/D4 frame standard is the ba
Page 245 and 246:
contains consecutive ones and zeros
Page 247 and 248:
• Line loopback/line build-out (L
Page 249 and 250:
process. The T3 multiplexer adds st
Page 251 and 252:
committee. The committee provided t
Page 253 and 254:
The photonic layer defines the elec
Page 255 and 256:
such as T1/E1, FDDI, and others. Th
Page 257 and 258:
SS7 signaling components are connec
Page 259 and 260:
SCCP operates as an OSI-RM Layer 3.
Page 261 and 262:
WAN point-to-point links. It can be
Page 263 and 264:
Figure 5.11. The ISDN protocol refe
Page 265 and 266:
• The R interface acts as a point
Page 267 and 268:
• Flag—This is an 8-bit (011111
Page 269 and 270:
terminals attached to the ISDN swit
Page 271 and 272:
X.25 networks are comprised of four
Page 273 and 274:
Frame Relay, like the ISDN effort i
Page 275 and 276:
• Flag—This functions as a fram
Page 277 and 278:
Figure 5.17. the B-ISDN reference m
Page 279 and 280:
environments is implemented using A
Page 281 and 282:
endpoints. A Virtual Path Link (VPL
Page 283 and 284:
ATM endpoints. The user adaptation
Page 285 and 286:
1. The ATM end-device issues a setu
Page 287 and 288:
Data-Link Framing Point-to-point de
Page 289 and 290:
PPP PPP can provide multiprotocol d
Page 291 and 292:
PPP Framing There are three HDLC fr
Page 293 and 294:
• The HDLC and PPP data-link prot
Page 295 and 296:
Chapter 6. Network Switches In this
Page 297 and 298:
Figure 6.1. Partial and full mesh m
Page 299 and 300:
protocol. Figure 6.3 illustrates th
Page 301 and 302:
All hosts can see the traffic that
Page 303 and 304:
To get a better understanding of th
Page 305 and 306:
Figure 6.5. A bridged LAN with span
Page 307 and 308:
support a path discovery method. So
Page 309 and 310:
or performance limitations, network
Page 311 and 312:
network data encryption, WAN reacha
Page 313 and 314:
The Impact of Switching on Traditio
Page 315 and 316:
• Switch backplane—Also referre
Page 317 and 318:
Switch Port Flow Control In full-du
Page 319 and 320:
In the event that the primary trunk
Page 321 and 322:
Figure 6.9. Layer 2 collision domai
Page 323 and 324:
Figure 6.10. Multiport repeaters an
Page 325 and 326:
Figure 6.11. Distributed and collap
Page 327 and 328:
utilization performance. To calcula
Page 329 and 330:
Ideally, the goal of all switch and
Page 331 and 332:
Cut-through uses the same technolog
Page 333 and 334:
VLANs A switch that supports VLAN p
Page 335 and 336:
MAC Address-Based VLANs Another com
Page 337 and 338:
Figure 6.13. Switches running indep
Page 339 and 340:
The configuration layer uses the Ge
Page 341 and 342:
Layer 2 infrastructures to operate
Page 343 and 344:
need. This method not only allocate
Page 345 and 346:
transmitting and receiving. Without
Page 347 and 348:
ATM-specific applications would be
Page 349 and 350:
ATM private-class switches are comp
Page 351 and 352:
Because both the VPI and VCI are us
Page 353 and 354:
environment. The goal is to have La
Page 355 and 356:
Broadcast and Unknown Server The Br
Page 357 and 358:
Figure 6.15. An LEC and its VCC rel
Page 359 and 360:
ATM hosts are accomplished by estab
Page 361 and 362:
• VLANs • Full-duplex switch po
Page 363 and 364:
Chapter 7. Introduction to Cisco Ro
Page 365 and 366:
The 4000 series routers come in a t
Page 367 and 368:
series routers, this partition can
Page 369 and 370:
need to crimp the CAT 5 strands fol
Page 371 and 372:
Use the cable set to build the cabl
Page 373 and 374:
Step 2. This command specifies whic
Page 375 and 376:
AppleTalk FDDI IPX Token Ring VINES
Page 377 and 378:
The IOS Command Line and Configurat
Page 379 and 380:
disconnect Disconnect an existing n
Page 381 and 382:
changes (user to privileged, for ex
Page 383 and 384:
• Router(config)#hostname test-ro
Page 385 and 386:
or • On 7x00 only, use: • •
Page 387 and 388:
Null Null interface Tunnel Tunnel i
Page 389 and 390:
Router(config)#ip rou? route routin
Page 391 and 392:
Ctrl+P, up arrow Previous command i
Page 393 and 394:
mop Copy from a MOP server (not ava
Page 395 and 396:
Now let's see what is on the PCMCIA
Page 397 and 398:
When copying any file, unless no pr
Page 399 and 400:
Ethernet LANs with a dedicated T1 c
Page 401 and 402:
Compiled Fri 03-Apr-98 07:00 by rna
Page 403 and 404:
172.16.2.0 /25 172.16.2.128 /26 or
Page 405 and 406:
Ridge-GW(config)# ip route 0.0.0.0
Page 407 and 408:
In addition to their native protoco
Page 409 and 410:
D - EIGRP, EX - EIGRP external, O -
Page 411 and 412:
Configuring Dumb Terminal Service T
Page 413 and 414:
Ctrl+Shift+6+X suspends a session).
Page 415 and 416:
cornpops|Printer on Cisco termserve
Page 417 and 418:
Concord-GW(config-if)#flowcontrol h
Page 419 and 420:
The AUX port configuration for Ridg
Page 421 and 422:
outer and enter the break sequence
Page 423 and 424:
Setting the conf-reg Value in ROM M
Page 425 and 426:
• Register setting 0x2010—Confi
Page 427 and 428:
8. 9. Router#configure terminal 10.
Page 429 and 430:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Page 431 and 432:
Router#config t Enter configuration
Page 433 and 434:
-#- ED --type----crc--- -seek--nlen
Page 435 and 436:
to xmodem or TFTP (2600 only) an IO
Page 437 and 438:
Mountain Standard Time (MST) -7 Pac
Page 439 and 440:
eference time is BB0FC7AA.95E93186
Page 441 and 442:
in production for a little while. T
Page 443 and 444:
use debug mode often. When using th
Page 445 and 446:
uucp UNIX-to-UNIX copy system IOS a
Page 447 and 448:
Log Management Logs are useless unl
Page 449 and 450:
IOS Authentication and Accounting I
Page 451 and 452:
hostnames (which can be corrected w
Page 453 and 454:
$telnet 192.160.56.5 Trying 192.160
Page 455 and 456:
In this example, the authentication
Page 457 and 458:
makes it easier to configure, becau
Page 459 and 460:
define what authentication type sho
Page 461 and 462:
Caution should be taken when using
Page 463 and 464:
pairs (similar to those used to cre
Page 465 and 466:
• Using rommon and disaster recov
Page 467 and 468:
In the following section, we review
Page 469 and 470:
Deciding to Use a Routing Protocol
Page 471 and 472:
Now, here is the qualifier: Not eve
Page 473 and 474:
If RIP was the routing protocol for
Page 475 and 476:
Distance Vector Protocols All routi
Page 477 and 478:
space) based on a power of 2. Class
Page 479 and 480:
address space), but you would run i
Page 481 and 482:
destination address that falls with
Page 483 and 484:
the different IP address spaces int
Page 485 and 486:
Weaknesses of Static Routing Static
Page 487 and 488:
Today, RIP is considered by some to
Page 489 and 490:
RIP 192.124.32.0 /24 192.124.35.1 3
Page 491 and 492:
All routers on the network keep tra
Page 493 and 494:
RIP's Value Today RIP is old, it's
Page 495 and 496:
• Better reliability—OSPF route
Page 497 and 498:
Figure 8.10. Single- and multi-area
Page 499 and 500:
• Internal routers—These router
Page 501 and 502:
to the backbone. In Figure 8.13, al
Page 503 and 504:
Figure 8.14. OSPF router designatio
Page 505 and 506:
oundary routers. They describe netw
Page 507 and 508:
outer's point of view. The path con
Page 509 and 510:
Autonomous Systems and Exterior Rou
Page 511 and 512:
Figure 8.16. The IGP to ERP handoff
Page 513:
Figure 8.17. The BGP finite state m
Page 516 and 517:
EGPs have been increasing in popula
Page 518 and 519:
Chapter 9. Advanced Cisco Router Co
Page 520 and 521:
specified ACL number range. Table 9
Page 522 and 523:
default, all traffic is denied. Onl
Page 524 and 525:
asbr-a2#config t Enter configuratio
Page 526 and 527:
trying to build ACLs with the comma
Page 528 and 529:
trace Multicast trace IGMP log Log
Page 530 and 531:
Tftp Trivial File Transfer Protocol
Page 532 and 533:
access-list 100 permit tcp any 172.
Page 534 and 535:
Table 9.5. AppleTalk ACL Filtering
Page 536 and 537:
Figure 9.1. The AnyCo corporate App
Page 538 and 539:
One word of caution: If you plan to
Page 540 and 541:
You can also log hits on ports by a
Page 542 and 543:
Table 9.8. Route-Map Operators for
Page 544 and 545:
exists, a group identifier (which c
Page 546 and 547:
hegel# With this configuration, bec
Page 548 and 549:
NAT is commonly used in a fashion s
Page 550 and 551:
The [prefix-length] or [netmask] se
Page 552 and 553:
NAT's Shortcomings Although NAT is
Page 554 and 555:
NOTE Administrators beware: Tunneli
Page 556 and 557:
connects, the active key informatio
Page 558 and 559:
encapsulation, framing, and line si
Page 560 and 561:
asbr-a2(config-if)#ip address 172.1
Page 562 and 563:
problem if you are provisioning ISD
Page 564 and 565:
22:41:34: %LINK-3-UPDOWN: Interface
Page 566 and 567:
POP mail request is made. Now let's
Page 568 and 569:
leibniz(config-if)#backup interface
Page 570 and 571:
When the primary link fails, the BR
Page 572 and 573:
1.544Mbps. The actual transport lin
Page 574 and 575:
the cost-effective and bandwidth-ef
Page 576 and 577:
interface configuration subcommand
Page 578 and 579:
it is possible to exchange packets
Page 580 and 581:
interface serial0.2 point-to-point
Page 582 and 583:
Figure 9.6. A multipoint FR example
Page 584 and 585:
2. ATM encapsulation must be enable
Page 586 and 587:
are commonly used in large-scale cl
Page 588 and 589:
persephone(config)#interface atm 3/
Page 590 and 591:
• The creation and application of
Page 592 and 593:
Chapter 10. Configuring IP Routing
Page 594 and 595:
After you have a list of requiremen
Page 596 and 597:
Control commands: Displaying
Page 598 and 599:
not active, it is quite common for
Page 600 and 601:
Incoming update filter list for all
Page 602 and 603:
When changing any IP routing behavi
Page 604 and 605:
asbr-a1(config-if)#^Z asbr-a1# When
Page 606 and 607:
For asbr-a2 to reach all the testne
Page 608 and 609:
192.168.160.0/30 is subnetted, 1 su
Page 610 and 611:
order to maintain computability wit
Page 612 and 613:
Configuring Dynamic IGP and EGP IP
Page 614 and 615:
passive-interface s1 By enabling th
Page 616 and 617:
asbr-a1(config-router)#network 12.0
Page 618 and 619:
To verify that the adjusted route m
Page 620 and 621:
The command is a general routing p
Page 622 and 623:
EIGRP, as I'm sure you have guessed
Page 624 and 625:
No matter how the announcement entr
Page 626 and 627:
Incoming update filter list for all
Page 628 and 629:
is adjustable using the router con
Page 630 and 631:
• IOS also supports various debu
Page 632 and 633:
outers: • Backbone Routers—Thes
Page 634 and 635:
process. The router would construct
Page 636 and 637:
e1/1 192.168.9.0 fe0/0 192.168.0.0
Page 638 and 639:
An alternative to this is to use th
Page 640 and 641:
C 192.168.191.0/24 is directly conn
Page 642 and 643:
Link State Age Interval is 00:20:00
Page 644 and 645:
C 192.168.191.0/24 is directly conn
Page 646 and 647:
to asbr-a1 was a remote office that
Page 648 and 649:
interface Serial1 ip address 192.16
Page 650 and 651:
which to exchange OSPF messages. Th
Page 652 and 653:
OSPF Monitoring Commands Throughout
Page 654 and 655:
• • • NOTE • will display
Page 656 and 657:
Figure 10.4. AURP tunnel interfaces
Page 658 and 659:
appletalk glean-packets hostname as
Page 660 and 661:
For many users, the usefulness of B
Page 662 and 663:
internal/Internet access router whe
Page 664 and 665:
externally destined traffic arrives
Page 666 and 667:
Routers asbr-a1/a2 and asbr-b1/b2 a
Page 668 and 669:
BGP Reflectors An alternative to ha
Page 670 and 671:
network 192.168.0.0 mask 255.255.25
Page 672 and 673:
dynamic routing protocols are used
Page 674 and 675:
Figure 10.8. An example network run
Page 676 and 677:
Controlling Redistribution In some
Page 678 and 679:
hostname ABR-a57 ! access-list 1 pe
Page 680 and 681:
access-list 2 deny 10.0.1.0 access-
Page 682 and 683:
Keep in mind that route-maps, li
Page 684 and 685:
Chapter 11. Network Troubleshooting
Page 686 and 687:
However, the most valuable tool of
Page 688 and 689:
• Description of primary function
Page 690 and 691:
of cable fault, different CSFSs are
Page 692 and 693:
For Windows Systems, check out the
Page 694 and 695:
command. On a Windows NT system, us
Page 696 and 697:
#Do not change these variables logf
Page 698 and 699:
# If any of the hosts fail to respo
Page 700 and 701:
upgrade. So, when the time comes to
Page 702 and 703:
throughput over time, instead of si
Page 704 and 705:
protocol is the most prone to perfo
Page 706 and 707:
NOTE When looking at network broadc
Page 708 and 709:
NOTE Another common network error n
Page 710 and 711:
and the physical ring segment that
Page 712 and 713:
tolerances the frames, timing shift
Page 714 and 715:
practical terms, this means that at
Page 716 and 717:
etransmissions, however, usually ha
Page 718 and 719:
4. Don't get lost in the big pictur
Page 720 and 721:
• Link and services monitoring, n
Page 722 and 723:
eports on network utilization, avai
Page 724 and 725:
o Bandwidth utilization rates o Rat
Page 726 and 727:
and improved management capabilitie
Page 728 and 729:
After the supported SNMP version is
Page 730 and 731:
Table 11.3. ASN.1 Keywords Used wit
Page 732 and 733:
application-wide tags, which are us
Page 734 and 735:
TestSequence ::= SEQUENCE { example
Page 736 and 737:
The MIB-2 and RMON-MIB modules are
Page 738 and 739:
iso.identfied-orgnaization.dod.inte
Page 740 and 741:
accepted values are getRequest, get
Page 742 and 743:
Spectrum is available in both UNIX
Page 744 and 745:
Figure 11.8. Windows NT 4.0 SNMP Ag
Page 746 and 747:
To access any of the NT SNMP agent
Page 748 and 749:
The installation of the SNMP agent
Page 750 and 751:
Figure 11.13. The Windows 95/98 Sel
Page 752 and 753:
Figure 11.15. Locating the Windows
Page 754 and 755:
Figure 11.17. The SNMP configuratio
Page 756 and 757:
2. Scroll to Network Connectivity o
Page 758 and 759:
sysLocation information, go to the
Page 760 and 761:
example that just implements the ba
Page 762 and 763:
protocol, service, and application
Page 764 and 765:
RFC 1089 RFC 1147 RFC 1155 RFC 1157
Page 766:
Appendix A. Binary Conversion Table
show all

Understanding the network.pdf - Back to Home

Create successful ePaper yourself

Delete template?

Save as template?