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ATM uses a connection-oriented, virtual circuit (VC) transport model that transports data in 53-byte cells between ATM endpoints. This small cell size makes ATM well suited to transmit voice, video, and data. ATM supports point-to-point bidirectional SVCs, unidirectional point-to-multipoint SVCs, and bidirectional point-to-point PVCs to establish connections between DTE endpoints. These VC connections, unlike traditional packet-switched WAN technologies, support Quality of Service (QoS) features that can provide guaranteed bit rate delivery services. As you are already familiar with the general operation concepts behind packet-switched networks (VCs, congestion control, and so on), we will look at how ATM implements these operational functions, using the ATM architecture model as a reference. ATM Architecture During the ISDN development process, the ITU-T realized that a need existed for developing standards to provide digital transmission services beyond that of the ISDN primary rate. The B-ISDN reference model, illustrated in Figure 5.17, uses the same basic control/user/management plane model used by the ISDN reference model. The B-ISDN layers and planes define the following functions:
Figure 5.17. the B-ISDN reference model. • Control plane—Manages the signaling and addressing functions needed to establish VCs (call setup and teardown) • User plane—Addresses the processes pertaining to the user data delivery functions • Management plane—Addresses system-wide management functions between the control and user layers • Physical layer—Defines the transmission of the ATM cells between the various DTE and DCE interfaces • ATM layer—Addresses the construction of the ATM cells (header generation, flow control, and VC addressing issues) • ATM adaptation layer—Provides the "processing" for different types of user data (voice, video, binary) between the ULPs and the ATM layer In 1990, the ITU-T revised the B-ISDN standards. In 1991, the ATM Forum was created (made up of Cisco, Stratcom, Newbridge, and NET) to develop a set of interoperability standards to facilitate the development of ATM-based products (ATM network adapters and switches). Without the ATM Forum, ATM would probably still be just a set of standards documents and no more. What the ATM Forum
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Understanding the Network A Practic
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IOS Authentication and Accounting S
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About the Reviewers These reviewers
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Tell Us What You Think As the reade
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mostly dealt with interconnecting m
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• A short introduction to SNMP Ap
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In theory, a computer network can o
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Coaxial cable has a single solid co
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• Radio transmission—It is achi
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• Baseband transmission applies t
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Ring Topology Figure 1.3. The bus t
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Packets and frames are often used a
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Asynchronous transmission involves
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Figure 1.6. Collision handling unde
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In a ring topology, a token is pass
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Repeaters The repeater was introduc
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the network. If your 50-node networ
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Figure 1.12. A collection of nodes
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their destination, type, and conten
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shop, you are using Novell's Direct
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Figure 1.14. The OSI and Internet r
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Layer 7: Application This layer pro
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end-to-end, sequenced data delivery
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outer, the delivery path might be d
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and network transport is a very imp
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Figure 1.16. The "bottom up" commun
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Chapter 2. The Networker's Guide to
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Internet Society, a nonprofit organ
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• First, it performs translations
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Figure 2.2. The IP header. • Vers
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To assist in the reassembly process
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Figure 2.3. IP address classes comp
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taking the natural mask of the addr
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Classful Subnetting Examples The im
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21 2,000 8,000 255.255.248.0 22 1,0
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classful-based address space model.
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Table 2.6. Classless Network Addres
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NOTE Because CIDR is used for addre
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will connect in the future, it is b
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Routers are also called intermediat
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IP datagrams for which the local ho
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1. The Layer 3 to Layer 2 address m
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3. Router B—Router B receives the
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connected networks. Figure 2.11 ill
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Figure 2.12. A simple regional (ISP
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gw1, gw2, gw4 3 gw1, gw3, gw4 3 gw1
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Dynamic routing might not be requir
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The transport layer as a whole repr
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window to reflect changes in the pa
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The TCP Header The TCP header provi
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53 DNS (Domain Name Service) 67 BOO
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SNMP Simple Network Management Prot
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uses both TCP and UDP for service d
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RFC 974 Mail routing and the domain
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Figure 3.1. Physical versus logical
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Figure 3.2. The AppleTalk protocol
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AppleTalk Address Resolution Protoc
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of 400 microseconds, in addition to
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Along with the SAP, there is a 5-by
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delivery is a best-effort delivery
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• DDP checksum (long header only)
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eachable within the internetwork. T
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information from the router's other
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AppleTalk Update Based Routing Prot
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• type is the service classificat
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application layers. AppleTalk has n
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Figure 3.10. ZIP message formats. E
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Printer Access Protocol Printer Acc
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Figure 3.11. Novell (IPX) protocol
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The other nodes on the network that
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Figure 3.13. IPX datagram format.
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the cumulative information gleaned
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• Hop Count is the number of rout
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Upper Layer Protocols IPX is used t
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Msg.Add.Name Adds a unique name to
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Related RFCs RFC 1001 RFC 1002 RFC
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service enhancement or replacement
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Figure 4.1. The LLC interfaces in r
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it does not provide for error recov
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and smooth pattern flow enables MTL
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cabling, backbone length 800m Categ
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combination of light refraction and
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NOTE Cladding is the glass "shell"
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Ethernet The original Ethernet prot
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UTP telephone cabling infrastructur
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Since the introduction of the IEEE
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In the event that two Ethernet end-
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The 802.3 frame type used in Figure
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• Frame check sequence (4 bytes)
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• Physical layer signaling (PLS)
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cable segment length (for coaxial s
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transmission medium using BNC (Brit
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Figure 4.12. A basic 3-cable 10Base
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Figure 4.14. 10Base-T hub-to-hub in
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Figure 4.16. 10Base-T in a consulta
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• Support for full-duplex operati
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mechanisms, in terms of encoding an
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etween different PHY encoding imple
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100Base Ethernet) is based on the p
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The Gigabit PHY The Gigabit PHY con
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CSMA/CD is sensitive to operating r
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The main advantage of using FDR ove
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have to transmit against the priori
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• Ring timing maintenance—The A
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check the lobe cable. If the lobe t
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Token Ring addresses are expressed
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• Report Active Monitor Error (RA
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they first join the ring or in the
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Figure 4.22. The IBM type 1 MIC con
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FDDI Work on the Fiber Distributed
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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: • Flag—This functions as a fram
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
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utilization performance. To calcula
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Ideally, the goal of all switch and
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Cut-through uses the same technolog
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VLANs A switch that supports VLAN p
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MAC Address-Based VLANs Another com
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Figure 6.13. Switches running indep
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The configuration layer uses the Ge
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Layer 2 infrastructures to operate
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need. This method not only allocate
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transmitting and receiving. Without
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ATM-specific applications would be
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ATM private-class switches are comp
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Because both the VPI and VCI are us
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environment. The goal is to have La
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Broadcast and Unknown Server The Br
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Figure 6.15. An LEC and its VCC rel
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ATM hosts are accomplished by estab
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• VLANs • Full-duplex switch po
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Chapter 7. Introduction to Cisco Ro
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The 4000 series routers come in a t
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series routers, this partition can
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need to crimp the CAT 5 strands fol
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Use the cable set to build the cabl
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Step 2. This command specifies whic
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AppleTalk FDDI IPX Token Ring VINES
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The IOS Command Line and Configurat
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disconnect Disconnect an existing n
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changes (user to privileged, for ex
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• Router(config)#hostname test-ro
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or • On 7x00 only, use: • •
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Null Null interface Tunnel Tunnel i
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Router(config)#ip rou? route routin
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Ctrl+P, up arrow Previous command i
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mop Copy from a MOP server (not ava
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Now let's see what is on the PCMCIA
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When copying any file, unless no pr
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Ethernet LANs with a dedicated T1 c
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Compiled Fri 03-Apr-98 07:00 by rna
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172.16.2.0 /25 172.16.2.128 /26 or
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Ridge-GW(config)# ip route 0.0.0.0
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In addition to their native protoco
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D - EIGRP, EX - EIGRP external, O -
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Configuring Dumb Terminal Service T
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Ctrl+Shift+6+X suspends a session).
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cornpops|Printer on Cisco termserve
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Concord-GW(config-if)#flowcontrol h
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The AUX port configuration for Ridg
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outer and enter the break sequence
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Setting the conf-reg Value in ROM M
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• Register setting 0x2010—Confi
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8. 9. Router#configure terminal 10.
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!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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Router#config t Enter configuration
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-#- ED --type----crc--- -seek--nlen
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to xmodem or TFTP (2600 only) an IO
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Mountain Standard Time (MST) -7 Pac
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eference time is BB0FC7AA.95E93186
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in production for a little while. T
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use debug mode often. When using th
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uucp UNIX-to-UNIX copy system IOS a
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Log Management Logs are useless unl
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IOS Authentication and Accounting I
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hostnames (which can be corrected w
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$telnet 192.160.56.5 Trying 192.160
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In this example, the authentication
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makes it easier to configure, becau
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define what authentication type sho
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Caution should be taken when using
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pairs (similar to those used to cre
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• Using rommon and disaster recov
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In the following section, we review
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Deciding to Use a Routing Protocol
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Now, here is the qualifier: Not eve
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If RIP was the routing protocol for
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Distance Vector Protocols All routi
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space) based on a power of 2. Class
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address space), but you would run i
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destination address that falls with
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the different IP address spaces int
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Weaknesses of Static Routing Static
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Today, RIP is considered by some to
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RIP 192.124.32.0 /24 192.124.35.1 3
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All routers on the network keep tra
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RIP's Value Today RIP is old, it's
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• Better reliability—OSPF route
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Figure 8.10. Single- and multi-area
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• Internal routers—These router
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to the backbone. In Figure 8.13, al
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Figure 8.14. OSPF router designatio
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oundary routers. They describe netw
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outer's point of view. The path con
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Autonomous Systems and Exterior Rou
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Figure 8.16. The IGP to ERP handoff
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Figure 8.17. The BGP finite state m
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EGPs have been increasing in popula
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Chapter 9. Advanced Cisco Router Co
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specified ACL number range. Table 9
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default, all traffic is denied. Onl
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asbr-a2#config t Enter configuratio
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trying to build ACLs with the comma
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trace Multicast trace IGMP log Log
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Tftp Trivial File Transfer Protocol
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access-list 100 permit tcp any 172.
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Table 9.5. AppleTalk ACL Filtering
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Figure 9.1. The AnyCo corporate App
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One word of caution: If you plan to
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You can also log hits on ports by a
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Table 9.8. Route-Map Operators for
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exists, a group identifier (which c
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hegel# With this configuration, bec
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NAT is commonly used in a fashion s
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The [prefix-length] or [netmask] se
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NAT's Shortcomings Although NAT is
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NOTE Administrators beware: Tunneli
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connects, the active key informatio
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encapsulation, framing, and line si
Page 560 and 561:
asbr-a2(config-if)#ip address 172.1
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problem if you are provisioning ISD
Page 564 and 565:
22:41:34: %LINK-3-UPDOWN: Interface
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POP mail request is made. Now let's
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leibniz(config-if)#backup interface
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When the primary link fails, the BR
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1.544Mbps. The actual transport lin
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the cost-effective and bandwidth-ef
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interface configuration subcommand
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it is possible to exchange packets
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interface serial0.2 point-to-point
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Figure 9.6. A multipoint FR example
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2. ATM encapsulation must be enable
Page 586 and 587:
are commonly used in large-scale cl
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persephone(config)#interface atm 3/
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• The creation and application of
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Chapter 10. Configuring IP Routing
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After you have a list of requiremen
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Control commands: Displaying
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not active, it is quite common for
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Incoming update filter list for all
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When changing any IP routing behavi
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asbr-a1(config-if)#^Z asbr-a1# When
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For asbr-a2 to reach all the testne
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192.168.160.0/30 is subnetted, 1 su
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order to maintain computability wit
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Configuring Dynamic IGP and EGP IP
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passive-interface s1 By enabling th
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asbr-a1(config-router)#network 12.0
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To verify that the adjusted route m
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The command is a general routing p
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EIGRP, as I'm sure you have guessed
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No matter how the announcement entr
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Incoming update filter list for all
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is adjustable using the router con
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• IOS also supports various debu
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outers: • Backbone Routers—Thes
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process. The router would construct
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e1/1 192.168.9.0 fe0/0 192.168.0.0
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An alternative to this is to use th
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C 192.168.191.0/24 is directly conn
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Link State Age Interval is 00:20:00
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C 192.168.191.0/24 is directly conn
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to asbr-a1 was a remote office that
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interface Serial1 ip address 192.16
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which to exchange OSPF messages. Th
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OSPF Monitoring Commands Throughout
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• • • NOTE • will display
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Figure 10.4. AURP tunnel interfaces
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appletalk glean-packets hostname as
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For many users, the usefulness of B
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internal/Internet access router whe
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externally destined traffic arrives
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Routers asbr-a1/a2 and asbr-b1/b2 a
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BGP Reflectors An alternative to ha
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network 192.168.0.0 mask 255.255.25
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dynamic routing protocols are used
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Figure 10.8. An example network run
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Controlling Redistribution In some
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hostname ABR-a57 ! access-list 1 pe
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access-list 2 deny 10.0.1.0 access-
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Keep in mind that route-maps, li
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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
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upgrade. So, when the time comes to
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throughput over time, instead of si
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protocol is the most prone to perfo
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NOTE When looking at network broadc
Page 708 and 709:
NOTE Another common network error n
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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
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• Link and services monitoring, n
Page 722 and 723:
eports on network utilization, avai
Page 724 and 725:
o Bandwidth utilization rates o Rat
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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
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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
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To access any of the NT SNMP agent
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The installation of the SNMP agent
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Figure 11.13. The Windows 95/98 Sel
Page 752 and 753:
Figure 11.15. Locating the Windows
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Figure 11.17. The SNMP configuratio
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2. Scroll to Network Connectivity o
Page 758 and 759:
sysLocation information, go to the
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example that just implements the ba
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protocol, service, and application
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RFC 1089 RFC 1147 RFC 1155 RFC 1157
Page 766:
Appendix A. Binary Conversion Table
show all

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