OSPF Case study Questions

toufiqtoufiq Member Posts: 34 ■■□□□□□□□□
I have almost completed my case study from JNCIP book.
but some below points needs to be cleared from you guys.

1. In some points, i found that metrics advertised with defaults values, my question is that is this will be requirement in JNCIP real exam or we will configure it with any value.

2.On page 190 I observed that R4 is configured with default metric 10 and Metric Type-2 while on page 233 R3 is configured with default metric 1 and with no metric type but both are ABRs with same configuration requirements.

Please guide, why we above difference.



  • hoogen82hoogen82 Member Posts: 272
    1. I think it would be best to assume it to be left to default. But if you decide to put any value.. make sure it doesn't break any other rule in the exam.

    2. Pg 190 requirement No type 5 or type 3 LSAs in area 10. => It doesn't mention type-1 or type-2 ... type-2 is default.. author just mentions it specifically and chooses to assign some value

    In Page 233 also there is no type 1 requirement.. author doesn't mention type 2.. as it is default.. And he chooses to assign some value.
    IS-IS Sleeps.
    BGP peers are quiet.
    Something must be wrong.
  • hoogen82hoogen82 Member Posts: 272
    This is something I got from Harry in another Forum.. Posting my email and his replies

    Thank You so much for that nice explanation. Somehow missed checking it.. I
    loaded the configs and saw what you meant..
    lab@R1# run show route exact detail

    inet.0: 12 destinations, 13 routes (12 active, 0 holddown, 0 hidden) (1 entry, 1 announced)
    *OSPF Preference: 150
    Next-hop reference count: 2
    Next hop: via ge-0/0/1.200, selected
    Age: 4d 17:11:32 *Metric: 11* Tag: 0
    Task: OSPFv2
    Announcement bits (1): 0-KRT
    AS path: I


    It did add up the metric count when it received the route from R3.

    lab@R1# run show ospf database nssa extensive

    OSPF link state database, Area
    Type ID Adv Rtr Seq Age Opt Cksum
    NSSA 0x800000b2 1821 0x20 0xa4cb 36
    * Type 1, TOS 0x0, metric 1, fwd addr, tag*
    Aging timer 00:29:38
    Installed 00:30:18 ago, expires in 00:29:39, sent 00:30:16 ago
    Last changed 4d 17:14:39 ago, Change count: 1
    NSSA 0x800000cc 610 0x20 0x6aea 36
    * Type 1, TOS 0x0, metric 1, fwd addr, tag*
    Aging timer 00:49:49
    Installed 00:10:04 ago, expires in 00:49:50, sent 00:10:02 ago
    Last changed 4d 17:14:26 ago, Change count: 1


    On Tue, Sep 29, 2009 at 1:13 PM, Harry Reynolds wrote:

    > I too thought the default for type 7 was always a metric type 2, but as
    > noted I have a confirmed errata note that the **default** route is
    > originated with a type 1 by default, hence the text is wrong on page 191.
    > While the metric type does not matter in this example, if you want metric 2
    > you do need to specify. Does seem that other nssa type 7s have type 2 as
    > their default, so no wonder no one can keep it straight.
    > [edit routing-instances ce1 protocols ospf]
    > regress@vpn11# run show version
    > Hostname: vpn11
    > Model: m10
    > JUNOS Base OS boot [10.0B3.7]
    > JUNOS Base OS Software Suite [10.0B3.7]
    > [edit routing-instances ce1 protocols ospf]
    - Show quoted text -
    > summaries are enabled (also the default), so technically the type-7
    > statement is not needed either. If no summaries is specified then a type 3
    > is generated, unless you also add the type-7 statement.
    > Nssa with summaries = type 7 is default, and the default has metric type 1
    > Nssa with no-summaries = type 3 by default, unless type 7 is specified,
    > again default has metric type 1
    IS-IS Sleeps.
    BGP peers are quiet.
    Something must be wrong.
  • toufiqtoufiq Member Posts: 34 ■■□□□□□□□□
    Thanks so it means that we dont need to configure metric-type-2 when configuring NSSA.further i have configured 1g metric on R1 & R2 but still not receving the 30 metric on R5. Can you please share the config for reference bandwidth on R1 router.

    root# run show route

    inet.0: 24 destinations, 25 routes (24 active, 0 holddown, 0 hidden)
    + = Active Route, - = Last Active, * = Both *[OSPF/150] 00:00:02, metric 13, tag 420
    > to via em2.0
  • hoogen82hoogen82 Member Posts: 272
    The requirement doesn't state to enable type-2.. so leaving it default would mean type 1.. If requirement asks us not the change the metric value when it traverses links.. Then you need type 2

    Reference bandwidth has to be 1g on all ospf routers...this is a standard rule..

    What you need is a bandwidth command

    Something like "set interface em0.0 bandwidth 100m" --> fast Ethernet
    IS-IS Sleeps.
    BGP peers are quiet.
    Something must be wrong.
  • adeel32adeel32 Member Posts: 27 ■□□□□□□□□□
    Thanks for your reply but the command you mentioned for setting interface bandwidth is not working in olive. Can you please crosscheck and confirm?
  • hoogen82hoogen82 Member Posts: 272
    I do not use Olives.. I just assumed it might work.. In real world this is the command used...
    IS-IS Sleeps.
    BGP peers are quiet.
    Something must be wrong.
  • AldurAldur Member Posts: 1,460
    Yea, I think with olives most physical interface properties aren't going to work. I think any physical properties that you can set for a normal OOB fxp0 interface can be set on an olive em or fxp interface.

    This is one of the unfortunate limitations of working with olives icon_sad.gif
    "Bribe is such an ugly word. I prefer extortion. The X makes it sound cool."

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