OSPF Confusion

JBeamJBeam Posts: 19Member ■□□□□□□□□□
I'm currently enrolled at a Cisco academy for the CCNA, we are finishing up Semester 3 and I took the practice exam today. I got this question wrong and I don't understand the reasoning, can someone help me out?
Router XYZ is to be added to OSPF area 0. Which of the following is the correct syntax for enabling OSPF on this router? 
	XYZ(config)# router ospf 
	XYZ(config)# router ospf 0 
	XYZ(config)# router ospf 10 
	XYZ(config)# router ospf process 0 
	XYZ(config)# router ospf process 10 
	XYZ(config)# router ospf processid 10

The correct answer is option 3. I chose option 2. To assign it to Area 0 wouldn't that be the correct command? I asked my instructor, but his answer just confused me more so I'm lookin for some other views.



  • rossonieri#1rossonieri#1 Posts: 800Member

    nope --- you are wrong icon_wink.gif

    pls check your note,

    your instructor maybe told you to look again your note icon_wink.gif

    conf#router ospf <proc-id>
    conf-router#network <ipsubnet> <inv-mask> area <area>

    cheers... icon_cool.gif
    the More I know, that is more and More I dont know.
  • mikej412mikej412 Posts: 10,090Member
    The area 0 was just a distraction.

    You set the process id on the router ospf command line. You set the area on the network command line.

    The question was the correct syntax for "enabling OSPF" -- with is the router ospf command.

    Process ID is required and the valid range is 1-65535. Only the 3rd one is the correct syntax for enabling OSPF.
    R3640-1#config t
    Enter configuration commands, one per line.  End with CNTL/Z.
    R3640-1(config)#router ospf ?
      <1-65535>  Process ID
    R3640-1(config)#router ospf 1
    R3640-1(config-router)#network ?
      area  Set the OSPF area ID
    R3640-1(config-router)#network area ?
      <0-4294967295>  OSPF area ID as a decimal value
      A.B.C.D         OSPF area ID in IP address format
    R3640-1(config-router)#network area 0
    :mike: Cisco Certifications -- Collect the Entire Set!
  • mgeorgemgeorge Posts: 777Member
    Answer 3 would be correct

    Answer 2 would be incorrect because you cannot use Process ID 0. It will give you an error.


    Router#conf t
    Enter configuration commands, one per line. End with CNTL/Z.
    Router(config)#router ospf ?
    <1-65535> Process ID

    Router(config)#router ospf

    You see you have to select a process id between 1 and 65535.

    Answer 1 would be %Incomplete Command.
    Answer 2 would be % Invalid input detected at '^' marker.
    Answer 3 would be Correct.
    Answer 4 would be %Unreconized Command.
    Answer 5 would be %Unreconized Command.
    Answer 6 would be %Unreconized Command.

    To assign a network to a paticular area you use the command
    Router(config-router)#network <networkip> <wildcard> area <area>

    Router(config-router)# area 0

    Hope this helps, enjoy icon_lol.gif
    There is no place like
  • mgeorgemgeorge Posts: 777Member
    Rrrrrr, looks like mike beat me to it AGIAN!!! icon_rolleyes.gif

    This is starting to become an everyday thing mike lol...
    There is no place like
  • JBeamJBeam Posts: 19Member ■□□□□□□□□□
    I understand now. Thanks for explaining. My instructor just said "0 isnt a proccess id" and that was it =/
  • JBeamJBeam Posts: 19Member ■□□□□□□□□□
    Another OSPF Question:
    What will be the result of OSPF DR/BDR elections in the network shown in the diagram? (Choose three.)
    R1 will be the DR for the network.
    R1 will be the DR for the network.
    R1 will be the DR for the network.
    R2 will be the DR for the network.
    R3 will be the DR for the network.
    R4 will be the DR for the network.

    I got this one right, I chose Options 2, 4 and 6. But now that I review, I'm not sure how I came up with the answer. I read the section again and it says that the highest Router ID will be come the DR, and to get the router ID its based off the IP address. Therefore wouldn't 1, 3, and 5 be correct?
  • JBeamJBeam Posts: 19Member ■□□□□□□□□□
    I figured it out, Its the HIGHEST IP on the router, makes it the default route. Been looking for the reasoning and found it! Thanks
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