CCNA Discovery 3 - Chapter 6

1,584 views

Published on

1 Comment
0 Likes
Statistics
Notes
  • thanks :)
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • Be the first to like this

No Downloads
Views
Total views
1,584
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
0
Comments
1
Likes
0
Embeds 0
No embeds

No notes for slide

CCNA Discovery 3 - Chapter 6

  1. 1. Routing With a Link-State Protocol Introducing Routing and Switching in the Enterprise – Chapter 6Version 4.0 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 1
  2. 2. Objectives Describe and plan a network using OSPF. Design and configure a network using single-area OSPF. Work with multi-protocol environments. © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 2
  3. 3. Describe and Plan a Network Using OSPF Link-state routing protocol Open standard developed by IETF Classless interior gateway protocol Divides the network into areas for scalability © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 3
  4. 4. Describe and Plan a Network Using OSPF Bandwidth determines the cost of a link Higher bandwidth = lower cost = desirable route• Cost = 100,000,000 / bandwidth of link in bps• Manual cost configuration at an interface: ip ospf cost © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 4
  5. 5. Describe and Plan a Network Using OSPF SPF algorithm (Diijkstra’s Algorithm) Each router has a topological tree SPF tree information stored in topology database © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 5
  6. 6. Describe and Plan a Network Using OSPF Adjacencies: neighbor relationships Hello protocol Router ID Role of loopback interfaces © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 6
  7. 7. Describe and Plan a Network Using OSPF Designated router (DR) Backup designated router (BDR) DROther © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 7
  8. 8. Describe and Plan a Network Using OSPF Area 0 Roles of routers in an OSPF Autonomous System: Area Border Router (ABR) Autonomous System Border Router (ASBR) © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 8
  9. 9. Design and Configure a Network Using Single-Area OSPFOSPF configuration steps: Enable OSPF + process ID Advertise networks + wildcard mask and area ID © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 9
  10. 10. Design and Configure a Network Using Single-Area OSPF Authentication protects integrity of routing information Simple password authentication Message Digest 5 (MD5) © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 10
  11. 11. Design and Configure a Network Using Single-Area OSPFTune OSPF parameters: Interface priority Router ID Loopback and interface addresses Bandwidth (cost ) © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 11
  12. 12. Design and Configure a Network Using Single-Area OSPFVerification and troubleshooting commands: show ip ospf neighbor show ip protocols, show ip route show ip ospf, show ip ospf interface © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 12
  13. 13. Work with Multi-Protocol Environments Default route configured on ASBR ASBR distributes the route into the OSPF network © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 13
  14. 14. Work with Multi-Protocol EnvironmentsBenefits of OSPF summarization: Reduces number of networks advertised Reduces memory requirements Reduces number of entries in router updates Isolates flapping and other problems to their location © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 14
  15. 15. Work with Multi-Protocol EnvironmentsOSPF limitations: Increased router memory and processing demands Strict design requirements Knowledgable administrator required Initial discovery process takes up network bandwidth © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 15
  16. 16. Work with Multi-Protocol Environments Administrative distance (AD) determines routes that appear in routing table © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 16
  17. 17. Summary OSPF is a classless interior link-state routing protocol used in enterprise networks OSPF uses bandwidth to generate the cost metric OSPF routers elect a DR and BDR on multi-access networks Router ID or router priority can be used to dictate the selection of DR and BDR The OSPF network command uses a wildcard mask Default route distribution and inter-area route summarization are used in OSPF networks © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 17
  18. 18. © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 18

×