Hello FRRouting community, I've tried to add an IPv6-only downstream to my dual-stack FRRouting-powered BGP setup, but for some reason the prefix of that downstream wasn't distributed to my upstream ISP. So, I consulted `show bgp summary` and spotted that this is the only route which isn't marked as `valid` indicated by a `*`. RPKI isn't enabled, otherwise I would have immediately suspected that to cause some prefix to be invalid. The only thing that makes this downstream different is that it is IPv6-only. What does it mean that a (received) prefix is considered "invalid"? Here is the output for `show bgp 2001:XX:YY::`: ``` BGP routing table entry for 2001:XX:YY::/48 Paths: (1 available, no best path) Not advertised to any peer ZZZZZZ 2a0d:f300:0:VVVV::1 (inaccessible) from 2a0d:f300:0:VVVV::1 (193.219.VV.VV) Origin IGP, invalid, external Last update: Mon Nov 9 09:00:00 2020 ``` ZZZZZZ ... is the downstreams ASN 2001:XX:YY:: ... is the IPv6 prefix the downstream wants to announce 2a0d:f300:0:VVVV::1 ... is the IPv6 address used to run the BGP router of the downstream 193.219.VV.VV ... is the IPv4 address assigned by me to the downstream, but he doesn't really use that one In case the FRRouting version is relevant for this issue, I'm running 7.3.1. Thanks in advance for any help, Michael