1 / 25

OSPF Packet Types, Hello Intervals, and Router Configuration for Effective Routing

This document explores key OSPF concepts, including the types of packets used for neighbor adjacency establishment, default hello packet intervals on point-to-point links, and route selection based on administrative distances (ADs). It discusses how to properly configure OSPF on routers and what factors influence OSPF neighbor relationships and DR (Designated Router) elections. Additionally, the document examines performance optimization techniques for OSPF across varied bandwidth links, helping network engineers apply best practices for routing efficiency.

brygid
Télécharger la présentation

OSPF Packet Types, Hello Intervals, and Router Configuration for Effective Routing

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. After 11.1 Last modified 12-2-10

  2. What type of OSPF packets are used to establish neighbor adjacencies? • Hello • DBD • LSR • LSU • LSAck 1 of 4

  3. How often are OSPF hello packets sent on point-to-point serial links by default? • 5 seconds • 10 seconds • 15 seconds • 30 seconds • Something else 2 of 4

  4. A router has three possible routes to the same internal network: one from RIP, one from OSPF, and one from EIGRP. All ADs are at default values. Which one will be placed into the routing table? • RIP • OSPF • EIGRP • More than one route will be placed into the routing table • None of the above 3 of 4

  5. How many of these values must match for routers to form an OSPF adjacency? • Hello interval • Router ID • Dead interval • Hold-down interval • DR • None • 1 • 2 • 3 • Some other number 4 of 4

  6. After 11.2

  7. Which commands correctly configure this router? • router ospf 1net 172.16.1.0net 10.0.0.0 • router ospf 0net 172.16.1.0 0.0.0.255 area 0net 10.0.0.0 0.0.0.3 area 0 • router ospf 1net 172.16.1.0 0.0.0.255 area 0net 10.0.0.0 0.0.0.3 area 0 • router ospf 1net 172.16.1.0 0.0.0.255 area 2net 10.0.0.0 0.0.0.3 area 3 • More than one of the above

  8. Which commands correctly configure R1, if R2 and R3 are configured to use OSPF process-id 2, area 0? • router ospf 2net 172.16.1.0 0.0.0.255 area 0net 10.0.0.0 0.0.0.3 area 0 • router ospf 1net 172.16.1.0 0.0.0.255 area 0net 10.0.0.0 0.0.0.3 area 0 • router ospf 1net 172.16.1.0 0.0.0.255 area 2net 10.0.0.0 0.0.0.3 area 2 • More than one of the above • None of the above

  9. Which commands correctly configure R1, if R2 and R3 are configured to use OSPF process-id 2, area 0? • router ospf 2net 172.16.1.0 0.0.0.255 area 0net 10.1.1.0 0.0.0.3 area 0net 10.2.2.0 0.0.0.3 area 0 • router ospf 1net 172.16.1.0 0.0.0.255 area 0net 10.1.1.0 0.0.0.3 area 0net 10.3.3.0 0.0.0.3 area 0 • router ospf 1net 172.16.1.0 0.0.0.255 area 2net 10.1.1.0 0.0.0.3 area 2net 10.3.3.0 0.0.0.3 area 2 • More than one of the above • None of the above

  10. No router-id command has been used. What is this router's OSPF Router ID? • 172.16.1.1 • 10.1.1.1 • 10.3.3.1 • Something else Interface IP-Address OK? Method Status Protocol FastEthernet0/0 172.16.1.1 YES manual up up Serial0/0/0 10.1.1.1 YES manual down down Serial0/0/1 10.3.3.1 YES manual down down

  11. No router-id command has been used. What is this router's OSPF Router ID? • 172.16.1.1 • 10.1.1.1 • 10.3.3.1 • Something else Interface IP-Address OK? Method Status Protocol FastEthernet0/0 172.16.1.1 YES manual administratively down down Serial0/0/0 10.1.1.1 YES manual up up Serial0/0/1 10.3.3.1 YES manual up up

  12. No router-id command has been used. What is this router's OSPF Router ID? • 172.16.1.1 • 10.1.1.1 • 10.3.3.1 • 2.67.200.1 • Something else Interface IP-Address OK? Method Status Protocol FastEthernet0/0 172.16.1.1 YES manual administratively down down Serial0/0/0 10.1.1.1 YES manual up up Serial0/0/1 10.3.3.1 YES manual up up Loopback1 2.67.200.1 YES manual up up

  13. After 11.3

  14. You have serial links of varying speeds. When should you use the bandwidth command? • To properly route traffic with EIGRP • To properly route traffic with OSPF • To properly route traffic with RIPv2 • More than one of the above • None of the above 1 of 2

  15. When should you use the ipospf cost command instead of the bandwidth command? • For serial links slower than 1.544 Mbps • To properly route with OSPF • To properly route with non-Cisco routers • More than one of the above • None of the above 2 of 2

  16. After 11.4

  17. What type of links are used in this network? • Point-to-point • Broadcast Multiaccess • NonbroadcastMultiaccess (NBMA) • Point-to-multipoint • Virtual links

  18. What is the DR in this OSPF network? • R1 is the DR • R2 is the DR • R3 is the DR • There is no DR • The answer cannot be determined

  19. A link on R1 changes state on this OSPF network, and sends out an LSU. How many copies of that LSU does R4 receive? • None • 1 • 2 • 3 • Some other number

  20. How many of these values affect DR choice in an OSPF election? • OSPF interface priority • Bandwidth • Delay • Router ID • 0 • 1 • 2 • 3 • Some other number

  21. This network uses OSPF. How many of these routers are DROthers? • None • 1 • 2 • 3 • Some other number

  22. After 11.5

  23. How many of these values are used to calculate the OSPF metric? • Bandwidth • Delay • Reliability • Load • 0 • 1 • 2 • 3 • 4 1 of 3

  24. Which adjustment can make OSPF converge faster, but will create more network traffic? • Change reference bandwidth • Redistribute default route • Modify intervals • Use multiple areas • Assign costs manually 2 of 3

  25. Which adjustment is needed to properly route networks with gigabit links? • Change reference bandwidth • Redistribute default route • Modify intervals • Use multiple areas • Assign costs manually 3 of 3

More Related