In my lab, ECMP is not working on R3. My output of show bgp ipv6 unicast 2001:db8::6/128 shows: Paths: (2 available, best #1, table default). In yours it is: best #2. Do you know what could be the issue?
Yes, I did. They look equally good. Both routes show in FIB and RIB, but only 1 is used. The only difference that I see in my output compare to yours is that "best #1" instead of "best #2"
@@BorisV8V If both are in the FIB, then both are being used. Best #1 and Best #2 isn't counting the number of best paths. It's telling you which of the two is technically "best". I'm betting your topmost route is best.