Solved: MPLS and upstream and downstream

zillah2004 · ‎03-13-2007

http://www.cisco.com/warp/public/105/mpls_faq_4649.shtml#qa6

Referring to the question below from the link above :

<quote>

Q. Is R3 a "Downstream" LSR to R4 for 10.1.1.0/24?

A. No, data flows from upstream to downstream.

</quote>

When I read the answer above, I felt there is a typo (any comment) , since the traffic flows from R4 through R3 to reach its final destination 10.1.1.0/24 , hence R3 downstream router to R4, because data flows from upstream (R4) to downstream (R3) to reach its network destination (10.1.1.0/24).

Any insight ?

Regards

Harold Ritter · ‎03-13-2007

Please read this statement that precedes the question:

"The R4 routing table has R1 and R2 as the "next-hops" to reach 10.1.1.0/24."

As you see, R3 is therefore not consider a downstream router.

Hope this helps,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México

View solution in original post

Harold Ritter · ‎03-13-2007

Please read this statement that precedes the question:

"The R4 routing table has R1 and R2 as the "next-hops" to reach 10.1.1.0/24."

As you see, R3 is therefore not consider a downstream router.

Hope this helps,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México