Refer to the exhibit. Which BGP metric is preserved when router R2 sends routes to confederation router R3?
A. AS_PATH
B. local preference
C. origin
D. AS4_PATH
Which BGP metric is preserved when router R2 sends routes to confederation router R3?
https://www.routerfreak.com/bgp-network-design-bgp-confederation/ supports B
correct answer is C – Origin will always be preserved
A is incorrect – R1, R2 and R3 are actually in different ASes (123,100,101)
It must be A (AS_PATH). It is well known mandatory attribute. Local preference is confined to an AS and is not advertised outside an AS.
Answer must be ‘A’