set protocols bgp parameters no-ipv6-auto-ra is documented, but only describes what the option does going forward — it doesn't mention that it has no effect on router-advertisement sending already active on an established session.

Confirmed empirically on a live VyOS 1.5.1 router (extended-nexthop/RFC8950 rcs_internal peering, unnumbered): after setting no-ipv6-auto-ra and committing, show running-config in vtysh correctly showed no bgp ipv6-auto-ra, but show interface <if> still reported BGP has configured RA and RA packets kept being sent on the wire — neither clear/reset bgp <neighbor> soft nor a full clear/reset bgp <neighbor> (hard) stopped it.

Root cause (per FRR source, bgpd/bgp_zebra.c's bgp_zebra_initiate_radv()/bgp_zebra_terminate_radv(), and upstream PR https://github.com/FRRouting/frr/pull/19487): RA termination is tied to the neighbor's remote-as being removed/re-added (peer_group_remote_as_delete()), not to a plain BGP session clear. The negation flag is only checked on the next initiate — not retroactively enforced on already-active RA.

Propose adding a note to docs/configuration/protocols/bgp.md's no-ipv6-auto-ra section clarifying this, so others don't spend time on clear/reset bgp expecting it to work.