My new BGP book: 'Internet Routing with BGP' by Iljitsch van Beijnum BGPexpert My BGP book from 2002: 'BGP' by Iljitsch van Beijnum

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BGP Expert Test

Answer these ten questions and we'll tell you if you're BGP expert. Enjoy!

For some questions, more than one answer is correct.

We also have another set of questions and answers for self-study purposes.

  • Question 1

    What is the version of BGP that first supported CIDR?

    BGP version 1
    BGP version 2
    BGP version 3
    BGP version 4
    BGP version 5
    None of the above

  • Question 2

    What are valid BGP terms? (Multiple answers are possible.)

    Communities
    Conglomerates
    Confederations
    Corporations
    None of the above

  • Question 3

    On top of which protocol does BGP run?

    Directly on top of IP
    UDP
    TCP
    None of the above

  • Question 4

    Suppose the IPv4 global BGP table has 880000 prefixes. A router connects to two ISPs that provide a full BGP feed and one peer that advertises 6000 prefixes. The network also has 4000 prefixes in OSPF. How many entries does the router have in its BGP table (BGP RIB)?

    1.77 million
    1.766 million
    0.886 million
    0.884 million
    0.88 million

  • Question 5

    The same numbers as in question 4: how many entries does the router have in its main routing table (main RIB)?

    1.77 million
    1.766 million
    0.886 million
    0.884 million
    0.88 million

  • Question 6

    In the global routing table, sometimes the same AS number shows up more than once in an AS path.

    Yes, that's normal BGP behavior
    Yes, if a router is configured to make the AS path longer
    No

  • Question 7

    When ARIN, RIPE or the APNIC assigns you the range 221.30.48.0 - 221.30.50.255 out of a 221.30.48.0 - 221.30.63.255 allocation, you should announce over BGP:

    Three /24's
    A /23 and a /24
    A /22
    A /20
    A /19
    None of the above

  • Question 8

    What do you need to use IPv6 with BGP?

    BGP version 3
    BGP version 4
    BGP version 5
    BGP version 6
    BGP multiprotocol extensions
    None of the above

  • Question 9

    Local preference is:

    Local to a single router
    Local to a single AS
    Local to a single neighbor connection
    None of the above

  • Question 10

    When selecting the best path, the BGP protocol takes into account the following information in the stated order:

    AS path, multi-exit discriminator, local preference
    AS path, local preference, multi-exit discriminator
    Local preference, AS path, multi-exit discriminator
    Multi-exit discriminator, AS path, local preference
    None of the above