R2 uses a route-map and takes all the traffic coming from AS 254 and tags it with the no-export community label and then it sends the community to R3 (155.1.23.3) and R5 (155.1.0.5) using the "send-community" command and I completely understand that.
What I dont understand is that why does R3 and R5 send the communitites to each other, but not to R2?
Thanks in advance!