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2204

  1. 1. 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 1 Introduction to Routing Protocols Session 2204 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 2
  2. 2. Agenda • IP, IPX Addressing Concepts • Generic Routing Concepts • Specific Routing Protocols • Static and Defaults Routes 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 3 MAC Address 48 Bit Hexadecimal (Base16) Unique Layer two address 1234.5678.9ABC First 24 bits = Manufacture Code Second 24 bits = Specific interface, assigned by IEEE assigned by Manufacture 0000.0c XX.XXXX XXXX.XX00.0001 All F’s= Broadcast FFFF.FFFF.FFFF 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 4
  3. 3. IP Addressing 32 Bits Network Host 8 Bits 8 Bits 8 Bits 8 Bits 172 . 16 . 122 . 204 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 5 IP Subnetting, Mask Network Host IP Address 172 16 0 0 Network Host Default Subnet 255 255 0 0 Mask Network Subnet Host 8-bit Subnet 255 255 255 0 Mask Use Host Bits, Starting at the High Order Bit Position 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 6
  4. 4. IP Address Classes Start 1 0 0 0 Class A: End 126 255 255 254 Mask 255 0 0 0 Start 128 0 0 0 Class B: End 192 255 255 254 Mask 255 255 0 0 Start 192 0 0 0 Class C: End 223 255 255 254 Mask 255 255 255 0 Class D: for multicast 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 7 IP Address Mask Formats The Router will display different Mask formats at different times. • bitcount ---172.16.31.6/24 • decimal ---- 172.16.31.6 255.255.255.0 • hexadecimal 172.16.31.6 0xFFFFFF00 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 8
  5. 5. Finding the IP Address on the LAN • ARP = Address Resolution UNIX Host A Protocol • Host and routers have pre assigned MAC addresses 1111.1111.1111 1111.1111.1111 5555.5555.5555 5555.5555.5555 • Host A sends a ARP request for router R1 2222.2222.2222 2222.2222.2222 • The ARP request is a broadcast packet R1 3333.3333.3333 3333.3333.3333 • R1 replies with ARP response unicast address 4444.4444.4444 4444.4444.4444 • Now both Host A and Router R1 R2 have the IP and MAC address for each other in their ARP Table 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 9 How Do I Get there From Here? UNIX Host UNIX Host Street A Street H • Path choice is based on location • Location is represented by an address 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 10
  6. 6. Host Addresses 172. 16. 200.11 10.1.1.1/8 255.255. 0. 0 E0 E1 172. 16.3.10 10.250.8.11 255.255.0.0 255. 0. 0. 0 172.16.12.12/16 10.180.30.118/8 IP: 172.16.2.1/16 IP: 10.6.24.2/8 Forwarding Table 172 .16 12 . 12 Network Interface 255.255 0.0 172.16.0.0 E0 Network Host 10.0.0.0 E1 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 11 Subnet Addressing 172.16. 3 . 5 172.16.2.11/24 E0 E1 255.255.255.0 172. 16. 2 . 2 172.16.3.100/24 255.255.255.0 172.16.2.160/24 172.16.3.150/24 IP: 172.16.2.1/24 IP: 172.16.3.1/24 Forwarding Table Network Interface 172 .16 2 160 172.16.2.0 E0 255.255 .255 .0 Network Subnet Host 172.16.3.0 E1 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 12
  7. 7. Discontiguous IP Subnet A Where Is 172.16.50.1 172 172.16.0.0? 255.255.255.0 192.168.1.4 .5 255.255.255.252 .13 B .6 172.16.40.1 172.16 255.255.255.0 192.168.1.12 255.255.255.252 .9 192.168.1.8 .14 255.255.255.252 .10 172.16.60.1 255.255.255.0 Routing Protocols will by Default Summarize Major Networks C 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 13 Variable Length Subnet Mask A 172.16.50.1 .5 255.255.255.0 172.16.1.4 255.255.255.252 .13 B .6 172.16.40.1 255.255.255.0 172.16.1.12 255.255.255.252 .9 172.16.1.X With a 172.16.1.8 .14 255.255.255.252 mask 255.255.255.252 .10 172.16.60.1 Or /30 the 1 subnet 255.255.255.0 my be broken into 64 Subnets C Conserve IP Addresses 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 14
  8. 8. IPX Addressing 80 Bits Network Node 32 Bits 48 Bits 000C 15C0 0077.0650.2328 IPX Network # IPX STATION # Usulay same a MAC address 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 15 Address Configuration Router (config-if) # ip address ip-address subnet-mask • Assigns an address and subnet mask • Starts IP processing on an interface ipx network network • Assigns a network number • Starts IPX processing on an interface • Must have ipx routing configured 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 16
  9. 9. Agenda • IP, IPX Addressing Concepts • Generic Routing Concepts • Specific Routing Protocols • Static and Defaults Routes 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 17 Convergence • Time required for router to identify and use an alternate path • Dependent on timer values and algorithm • Difficult to predict precisely A,B,C A,B,C B,C D,E,F D,E,F D,E,F 2 4 6 Router’s 5 and 6 C E F B D Have no knowledge of A the new Network A Yet 1 3 A,B,C 5 A,B,C B,C D,E,F D,E,F D,E,F 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 18
  10. 10. Load Balancing T1 T1 R2 N1 N2 R1 R4 T1 R3 T1 • Equal cost paths • Rapid failover 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 19 Load Balancing 256K 768K R2 N1 N2 R1 512K R4 R3 T1 • Unequal cost load balancing: Eigrp 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 20
  11. 11. Holddown I Will Ignore Routes to X While in Holddown x • Sets minimum convergence time • Prevents forwarding loops 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 21 Forwarding Loop: A Routing Disagreement Packets for Network X • Packets do not get to the destination • Temporary traffic surge until convergence 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 22
  12. 12. Split Horizon “ Do not send routing data back in the direction from which it came ” 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 23 Split Horizon Frame Relay Multipoint Network Router 2,3,4 All advertise their Respective Ethernets to Router D, Router D knows all networks PVC 2 A A PVC D 1 3 B B S0 PVC C 4 C 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 24
  13. 13. Split Horizon Frame Relay Network Router 1 Advertises network D to routers 2,3,4 2 A PVC PVC D 1 3 B S0 PVC Router 1 4 C Knows all networks but Will only advertise D out of S0 Because it learned A,B,C from S0 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 25 Metrics (Cost) • Numeric value used to choose among paths • RIP/RIPv2 is hop count and ticks (IPX) • OSPF/ISIS is interface cost (bandwidth) • (E)IGRP is compound • BGP can be complicated • Path determination depends on metric 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 26
  14. 14. Agenda • IP, IPX Addressing Concepts • Generic Routing Categories • Specific Routing Protocols • Static and Defaults Routes 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 27 Forwarding Table One Forwarding Table per Router One Forwarding Table per Network Protocol Network # Interface Next Hop Metric Age Source 198.113.181.0 Ethernet0 192.150.42.177 [170/304793] 02:03:50 D 198.113.178.0 Ethernet0 192.150.42.177 [110/9936] 02:03:50 O 192.168.96.0 Ethernet0 192.150.42.177 [120/3] 00:00:20 R 192.168.97.0 Ethernet0 C 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 28
  15. 15. Building the Forwarding Table • Directly connected Routes that the router is attached to • Static Routes are manually defined • Dynamic Routes protocol are learned from a Protocol 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 29 Routing Protocols I Know About: I Know About: Network A Network X Network B Network Y A Network C Routing Update Network Z X B Y C Exchanges Network Knowledge Z • Routing protocol updates are exchanged by routers to learn about paths to other logical networks • Each routing protocol offers features that can make it desirable as part of an internetwork design 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 30
  16. 16. Routing Protocol Goals • Optimal path selection • Easy to configure • Loop-free routing • Adapts to changes easily and quickly • Fast convergence • Does not create a lot • Limited design of traffic administration • Scales to a large size • Minimize update traffic • Compatible with existing • Handle address limitations hosts and routers • Support hierarchical • Supports variable length topology subnet masks and • Incorporate rapid discontiguous subnets convergence • Supports policy routing 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 31 IP RIP • Routing Information • RFC 1058 Protocol • Simple = limited • Widely available • Slow convergence • Hop count metric • No VLSM • Periodic update • No discontiguous • Easy to implement subnets • One of the first • Max 15 Hops available 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 32
  17. 17. RIP—Distance Vector Net A Net D R1 R2 R3 Net B Net C E0 S0 S0 S1 S0 E0 Network Interface Network Interface Network Interface A E0 B S0 C S0 B S0 C S1 D E0 C S0 A S0 B S0 D S0 D S1 A S0 Send RIP Routing Table to Neighbors 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 33 Broadcast Routing Updates All Stations Have to Listen to Rip Broadcast’s S 10.1.1.1 D 255.255.255.255 RIP V1 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 34
  18. 18. RIP Metric 1 Hop Hops Path A R2 T1 T1 56k R1 R3 Path B 0 Hops 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 35 RIP V2 • RFC 1723 • Cisco IOS® 11.1 support • Advertises masks • Variable length subnet masks • Route summarization • Routing updates use multicast • Authenticated updates using MD5 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 36
  19. 19. Multicast Routing Updates RIP V2 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 37 When to Use RIPv2 • Subnet mask support • Reduce broadcast load • Validated updates • Multivendor environment 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 38
  20. 20. IPX RIP • Widely available • Tied to SAP protocol • Hop count metric • Simple = limited • Ticks (1/18 sec) • Slow convergence • Periodic update • No default route • Easy to implement • Routing loops • Free on servers • Max 15 hops 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 39 IPX RIP—Ticks • Ticks are used • IPXWAN to determine calculates for server timeout its interfaces • Default for LAN • can be set via interfaces is 1 the ipx delay number interface • Default for WAN sub command interfaces is 4 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 40
  21. 21. IGRP • Interior Gateway • Cisco IOS 9.21 Routing Protocol • Periodic update • Cisco developed • No VLSM • Distance vector • Default timers • Compound produce slow metric convergence 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 41 IGRP Compound Metric • Administrative weight T1 R2 • Delay • Bandwidth T1 • Reliability 56k • Load R1 R3 (K2 * BW) K5 = ((K1 * BW + (256-load) + K3* delay)) * (reliability + K )) 4 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 42
  22. 22. How the IGRP Metrics Work Delay Metric- D1 D2 D3 Based on D1 + D2 + D3 Bandwidth 1.5 Mbps 64 kbps 1.5 Mbps Metric-Based on 64 kbps • Bandwidth dominates short paths • Delay dominates long paths • Configure bandwidth on all interfaces 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 43 Enhanced IGRP • Extremely fast • Best of DV and LS convergence • Low overhead • VLSM support • Guaranteed • Discontiguous loop-free subnets • Reliable, incremental • Arbitrary route update-based summarization • Multiprotocol: • Supports prefix and IP, IPX®, AppleTalk host routing • Easy to configure 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 44
  23. 23. Advanced Distance Vector On Startup Routing Tables Are Exchanged; Routing A 27 Table Built Based on Best B 12 Paths from Topology Table A 1 Z C 35 B 13 C 20 A 27 Z A Q 2 1 Q B Z 13 Q Y 5 X C X 13 B 12 Z .. .. .. Y’s Table A 5 Topology Table B 3 C 3 X • Construct neighbor tables X’s Table • Construct topology tables • Compute routes 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 45 EIGRP Tables • Topology table • Neighbor table • Acted upon by DUAL • Keeps adjacent neighbor’s address • All routes advertised by neighbors • Keeps the hold time • List of neighbors for • Information for each route reliable transport • Routes passive or active 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 46
  24. 24. Diffusing Update Algorithm (DUAL) • DUAL is a loop-free routing algorithm that performs a diffused computation of a routing table Uses a new routing algorithm Achieves fast convergence Network changes propagate only to affected nodes (“bounded updates”) • No need for route holddown 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 47 IPX EIGRP • Automatic redistribution of routes into RIP/SAP • Maximum network size is 224 hops vs 15 for RIP • Incremental SAPs sent, reducing bandwidth usage • All other benefits of EIGRP 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 48
  25. 25. When to Use EIGRP • Very large, complex networks • VLSM • For fast convergence • Little network design • Multiprotocol support 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 49 Link State Routing Z’s Link State Q’s Link State Topology Information Is Z Kept in a Database Separate from the Forwarding Table A Q 2 B Z 13 Q Y C X 13 • OSPF X X’s Link State • IS-IS • NLSP 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 50
  26. 26. Link State Routing • Neighbor discovery • Constructing an LSA (Link State Advertisement) • Distribute LSA • Compute routes using SPF (Shortest Path First) • On network failure New LSAs flooded All routers recompute link state databases 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 51 OSPF • Open Shortest • Fast convergence Path First • Variable-length • Link state or SPF subnet masks technology • Discontiguous • Developed by OSPF subnets working group of • No periodic updates IETF (RFC 1253) • Route authentication • Designed expressly for TCP/IP Internet • Delivered two years environment after IGRP 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 52
  27. 27. OSPF Areas and Rules Area • Backbone area (0) Border Router must be present • All other areas Area 2 Area 3 must have Area 0 Internal connection Backbone Router to backbone Router • Backbone must Area 4 be contiguous Area 1 • Do not partition area (0) Autonomous Internet System (AS) Border Router 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 53 When to Use OSPF • Large hierarchical networks • Complex networks, except… Topology restrictive Additional network design • VLSM • Fast convergence • Multivendor 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 54
  28. 28. IS-IS • IS = Intermediate • ISO 10589 System • Two types of areas: • Dual IS-IS Level-1 other areas • Integrated IS-IS Level-2 backbone • Metric is 10 bits • Default for wide each level • All interfaces • Much like OSPF default to 10 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 55 NetWare Link Services Protocol • Derived from ISIS • NLSP specs 3 levels of routers • Only two levels are defined • Spec is Novell NLSP version 1.1 http://www.novell.com http://developer.novell.com/research 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 56
  29. 29. BGP • RFC 1771 • Many options for policy enforcement • Border Gateway Protocol • Classless Inter Domain Routing • Version 4 is current (CIDR) • Exterior routing • Widely used for protocol (vs. Internet backbone interior) • AS=Autonomous • Uses TCP for systems transport 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 57 BGP Basics Peering A C AS 100 AS 101 B D E • Runs over TCP AS 102 • Path vector protocol • Incremental update 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 58
  30. 30. Internal BGP (IBGP) Peering AS 100 D A B E • BGP peer within the same AS • Not required to be directly connected • IBGP neighbors should be fully meshed • Few BGP speakers in corporate network 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 59 External BGP (EBGP) Peering A AS 100 AS 101 C B • Between BGP speakers in different AS • Should be directly connected • Don’t run an IGP between EBGP peers 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 60
  31. 31. Policy Drives BGP Requirements AS 200 Static Route BGP AS 100 BGP AS 400 BGP AS 300 • Policy for AS 100: Always use AS 300 path to reach AS 400 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 61 When Not to Use BGP Network Static Number C A ISP Runs BGP B B Advertise Default Network Via IGP Use a Static Route to Provide Connectivity • Avoid BGP configuration by using default networks and static routes Appropriate when the local policy is the same as the ISP policy 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 62
  32. 32. Agenda • IP, IPX Addressing Concepts • Generic Routing Categories • Specific Routing Protocols • Static and Defaults Routes 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 63 Static Routes • Routes configured manually • Useful when few or just one route exist • Can be administrative burden • Frequently used for default route 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 64
  33. 33. Administrative Distance • The router treats different routing protocols with a different preference Route Source Default Distance Connected Interface 0 Static Route 1 Enhanced IGRP Summary Route 5 External BGP 20 Internal Enhanced IGRP 90 IGRP 100 OSPF 110 IS-IS 115 RIP 120 EGP 140 External Enhanced IGRP 170 Internal BGP 200 Unknown, Discard Route 255 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 65 Floating Static Routes • A static route with a high distance • Can be overridden by dynamic info T1 172.16.3.2 3 172.16.1.0 ISDN C15C0 172.16.3.1 3 ip route 172.16.1.0 255.255.255.0 172.16.3.1 140 ipx route C15C0 3.0000.0c15.3628 floating-static 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 66
  34. 34. Default Routes • Route used if no match is found in forwarding table • Can be carried by routing protocols • Two models Special network number: 0.0.0.0 (IP) -2 (IPX) Flagged in routing protocol • Protocols support multiple models 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 67 Creating a Default Route • RIP, RIPv2: network 0.0.0.0 • IGRP, EIGRP: ip default-network • OSPF:ISIS default originate • IPX: ipx route default • default gateway is for “host mode” 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 68
  35. 35. Default IP Subnet 172.16.0.0 Internet s0 s1 172.16.1.0 • Two defaults For unknown networks For unknown subnets • Controlled by ip classless 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 69 Comparison of Routing Protocols Link Traditional Advanced Path State Distance Distance Vector Vector Vector Scalability Good Low Excellent Outstanding Bandwidth Low High Low Low Memory High Low Moderate High CPU High Low Low Moderate Convergence Fast Slow Fast Moderate Configuration Moderate Easy Easy Hard 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 70
  36. 36. Internet Routing Protocols • IP routing protocols are characterized as Name Type Proprietary Function Updates Metric VLSM Summ RIP DV No Interior 30 Sec Hops No Auto RIPv2 DV No Interior 30 Sec Hops Yes Auto IGRP DV Yes Interior 90 Sec Comp No Auto EIGRP Adv DV Yes Interior Trig Comp Yes Both OSPF LS No Interior Trig Cost Yes Man IS-IS LS No Interior Trig Cost Yes Auto BGP Path Vec No Exterior Incr N/A Yes Auto 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 71 Topology/Technology Considerations • Routing and services overhead is usually not a big deal when you have a lot of bandwidth (i.e. LANs) • Protect WAN bandwidth using update-based protocols—more bandwidth and buffers for application traffic • High densities of sub (interfaces) can cause “hot spots” and router CPU overload • NBMA (Non-Broadcast Multi-Access) technologies always require good design practices 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 72
  37. 37. For Further Reference… • EIGRP Network Design Solutions by Ivan Pepelnjak,(ISBN: 1578701651) • Interconnections : Bridges and Routers by Radia Perlman (ISBN: 0-20156-332-0) • Internetworking with TCP / IP, Volume 1: Principles, Protocols, and Architecture by Douglas Comer (ISBN: 0-13216-987-8) • IP Routing Fundamentals by Mark Sportack (ISBN: 1-57870-071-x) • IP Routing Primer by Robert Wright (ISBN: 1-57870-108-2) • OSPF Network Design Solutions by Thomas, Thomas M. (ISBN: 1-57870-046-9) 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 73 For Further Reference… • Routing in the Internet by Christian Huitema (ISBN: 0-13132-192-7) • OSPF Network Design Solutions by Thomas, Thomas M. (ISBN: 1-57870-046-9) • ISP Survival Guide : Strategies for Running a Competitive ISP by Geoff Huston (ISBN:0-47131-499-4) • Internet Routing Architectures by Bassam Halabi (ISBN: 1-56205-652-2) 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 74
  38. 38. Thank You! • Related sessions: 2208 Deploying IGRP/EIGRP 2205 Deploying OSPF 2209 Deploying BGP 2200 Advanced IP Routing 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 75 Introduction to Routing Protocols Session 2204 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 76
  39. 39. Please Complete Your Evaluation Form Session 2204 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 77 2204 1241_05_2000_c1 © 2000, Cisco Systems, Inc. 78

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