רשימת קורסים כניסה

מידע

יוצרים Olivier Bonaventure
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כניסה

כניסה

BGP Route Reflection

These questions assume that you have read the following article :

Jong Han Park et al, BGP Route Reflection Revisited, IEEE Communications Magazine, June 2012, http://irl.cs.ucla.edu/~j13park/rr-commag.pdf

שאלה 1: BGP Attributes

Which of the BGP attributes are only used when there are BGP Route Reflectors inside a network ?

שאלה 2: Number of iBGP sessions

Consider the network whose topology is shown by the ASCII drawing below.

R1------R2----R6
|       |
R3------R4----R5

All these routers belong to the same AS. If one of them is a Route Reflector, how many iBGP sessions do you need to create ?

שאלה 3: Number of iBGP sessions

Consider the network whose topology is shown by the ASCII drawing below.

R1------R2----R6
|       |
R3------R4----R5

All these routers belong to the same AS. If R2 and R4 are redundant route reflectors, how many iBGP sessions do you need to create inside this AS ?

שאלה 4: Basics of BGP Route Reflection

Consider the simple network shown in the ASCII figure below.

    +                  +
Rx -+- R1 --- RR --- R2 -+- Ry
    +                  +

In this network, R1, RR and R2 belong to AS1. R1 and R2 are clients of the Route Reflector RR. Rx belongs to AS2 and Ry to AS3. These two ASes are connected to AS4 that advertises prefix p. This implies that :

  • Rx advertises prefix p with AS-Path:`AS2:AS4 to R1
  • Ry advertises prefix p with AS-Path:`AS3:AS4 to R2

If link R1-RR has a cost of 1 and link RR-R2 a cost of 2, what are the BGP routes known by these three routers ? (routes marked with * are the best ones, we assume that BGP Nexthop self is not used)

שאלה 5: Basics of BGP Route Reflection

Consider the simple network shown in the ASCII drawing below.

    +                  +
Rx -+- R1 --- RR --- R2 -+- Ry
    +                  +

In this network, R1, RR and R2 belong to AS1. R1 and R2 are clients of the Route Reflector RR. Rx belongs to AS2 and Ry to AS3. Rx advertises prefix p with AS-Path:`AS2:AS4 to R1

If link R1-RR has a cost of 1 and link RR-R2 a cost of 1, what are the BGP routes known by these three routers ? (routes marked with * are the best ones, BGP Nexthop self is not used in this network)