Refer to the Exhibit
The 10.200/16 network is announced as an IS-IS route by R2 to its IS-IS neighbors. R3 and R4
are configured with an IS-IS export policy, which announces this route to R5 and R6.
Which statement is true?
A.
When viewed on R5 the 10.200/16 route will be marked down.
B.
When viewed on R5 the 10.200/16 route will be marked up.
C.
The 10.200/16 route will not be visible on R5.
D.
The 10.200/16 route will be marked with the overload bit.
Explanation:
As a result of provided information answer is B.
Route is not marked as down in order to disable the attached bit on R4 and R5.
Answer should be A, reason : when route cross the boundary from level 2 to level 1, it will be marked as down. THis is a way to prevent loop – so that any route marked as down should NOT be re-advertised back up from level 1 to 2.
area 2 routes must be leaked to area1 other-vise they appears down….A is correct answer.
correction L2 ==>> L1 level 2 to Level1
Correct answer is B. Reference below RFC and search for “The up/down Bit”
https://tools.ietf.org/html/rfc5305#section-4.1
The down mark is for going up a tier, for example level 1 back to level 2 distribution to prevent loops