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shop, you are using Novell's Directory Services, based on the X.500 standard. The X.25 network standard is also an ISO creation. X.25 is used to connect ATM machines, credit card validation systems, and some of the older networks run TCP/IP over it. X.25 has an error checking and correcting version. Frame Relay and X.25 are commonly used WAN protocols. All Cisco Systems products are GOSIP compliant. Figure 1.13. The U.S. government OSI profile. There are several Network Communication Protocol (NCP) suites available to interconnect computers today. For example, DECnet was developed to connect end stations and Digital VAX systems. IBM has Systems Network Architecture (SNA) for mainframe and mini-communication. Apple Computer uses AppleTalk to provide print and file access. Novell's NetWare network operating system uses the IPX/SPX protocol suite based on Xerox's open standard XNS system. Of course, there is the "mother" of all protocol suites: TCP/IP. Transmission Control Protocols, on the other hand, (before OSI) were largely considered separate from the complete data communication process. Data transport was seen as different
from data communication. NCPs defined operational specifications and support for specific TCPs or operated over their own proprietary TCP. The problem with having a large variety of network transmission and communication protocols is that they do not interoperate with one another from a protocol basis, and some are even closed proprietary systems with limitedsupport for proprietary computer systems. The OSI dream (created by telecommunications and business worlds drifting in the sea of incompatible protocols) was to fulfill a rather difficult task: to build data communication networks that work over a variety of infrastructures and allow communication between a variety of system types. Because the majority of NCPs were vendor-specific—that is, SNA, DECnet, AppleTalk, Novell—TCP/IP was the only contender. TCP/IP was a vendor-independent protocol suite developed in the government and research world. This meant that it was a public domain network communication protocol suite, free from royalty obligations. Until OSI came along, the standard networking reference model for many was the Internet-RM (based on the TCP/IP protocol suite), as shown in Figure 1.14.
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 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
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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
Page 153 and 154:
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,
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Figure 4.25. FDDI MAC data frame an
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topologies needed for the transmiss
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Chapter 5. WAN Internetworking Tech
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Placing a Call The functional model
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LATAs to provide local exchange ser
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The PSTN was originally designed fo
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sampling rate is 8,000 times per se
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Figure 5.1. A multiplexer from a lo
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Table 5.1. The American (DS) and In
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The M24/D4 frame standard is the ba
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contains consecutive ones and zeros
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• Line loopback/line build-out (L
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process. The T3 multiplexer adds st
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committee. The committee provided t
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The photonic layer defines the elec
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such as T1/E1, FDDI, and others. Th
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SS7 signaling components are connec
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SCCP operates as an OSI-RM Layer 3.
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WAN point-to-point links. It can be
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Figure 5.11. The ISDN protocol refe
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• The R interface acts as a point
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• Flag—This is an 8-bit (011111
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terminals attached to the ISDN swit
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X.25 networks are comprised of four
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Frame Relay, like the ISDN effort i
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• Flag—This functions as a fram
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Figure 5.17. the B-ISDN reference m
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environments is implemented using A
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endpoints. A Virtual Path Link (VPL
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ATM endpoints. The user adaptation
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1. The ATM end-device issues a setu
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Data-Link Framing Point-to-point de
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PPP PPP can provide multiprotocol d
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PPP Framing There are three HDLC fr
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• The HDLC and PPP data-link prot
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Chapter 6. Network Switches In this
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Figure 6.1. Partial and full mesh m
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protocol. Figure 6.3 illustrates th
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All hosts can see the traffic that
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To get a better understanding of th
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Figure 6.5. A bridged LAN with span
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support a path discovery method. So
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or performance limitations, network
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network data encryption, WAN reacha
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The Impact of Switching on Traditio
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• Switch backplane—Also referre
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Switch Port Flow Control In full-du
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In the event that the primary trunk
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Figure 6.9. Layer 2 collision domai
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Figure 6.10. Multiport repeaters an
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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
Page 467 and 468:
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
Page 483 and 484:
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
Page 491 and 492:
All routers on the network keep tra
Page 493 and 494:
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
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asbr-a2(config-if)#ip address 172.1
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problem if you are provisioning ISD
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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
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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
Page 664 and 665:
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
Page 684 and 685:
Chapter 11. Network Troubleshooting
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However, the most valuable tool of
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• Description of primary function
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of cable fault, different CSFSs are
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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
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# 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
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NOTE Another common network error n
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and the physical ring segment that
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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
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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
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iso.identfied-orgnaization.dod.inte
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accepted values are getRequest, get
Page 742 and 743:
Spectrum is available in both UNIX
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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
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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
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