How to filter IPv6 prefixes in Quagga BGP?

Question

Border Gateway Protocol

Good afternoon!

There is the following task: there is a central network (AS65000, networks 192.168.1.0/24 and 2001:470:xxxx::/64) and several additional ones (AS651yy, networks 172.16.yy.0/24 and 2001:470:yyyy::/ 64). Each network has exactly one gateway under Linux or FreeBSD, with the Quagga package. Gateways add. networks are connected to the central network using OpenVPN (subnet topology, networks 172.18.65.0/24 and 2001:470:tttt::/64 are used for tunnels, the central network has tunnel addresses 172.18.65.1 and 2001:470:tttt::1, additional -- 172.18.65.yy and 2001:470:tttt::yy).

You need to configure BGP so that:
* Routes to all additional
networks are available to the core network * Routes to the core network are available to additional networks
* Routes between each other were NOT available to additional networks

Access to some networks is provided only by IPv4, to some - by IPv4 and IPv6, to some - only by IPv6.

At the moment, the bgpd configuration on the central gateway looks like this:

bgpd.conf

!
router bgp 65000
  bgp router-id 172.0.0.1
  !
  neighbor 172.18.65.10 remote-as 65110
  neighbor 172.18.65.10 prefix-list c10-filter-in in
  neighbor 172.18.65.10 prefix-list clients-filter-out out
  !
  neighbor 172.18.65.11 remote-as 65111
  neighbor 172.18.65.11 prefix-list c11-filter-in in
  neighbor 172.18.65.11 prefix-list clients-filter-out out
  !
  neighbor 172.18.65.12 remote-as 65112
  neighbor 172.18.65.12 prefix-list c12-filter-in in
  neighbor 172.18.65.12 prefix-list clients-filter-out out
  !
  neighbor 172.18.65.27 remote-as 65127
  neighbor 172.18.65.27 prefix-list c27-filter-in in
  neighbor 172.18.65.27 prefix-list clients-filter-out out
  !
  neighbor 2001:470:tttt::27 remote-as 65127
  neighbor 2001:470:tttt::27 prefix-list c27-filter6-in in
  neighbor 2001:470:tttt::27 prefix-list c27-filter6-out out
  !
  neighbor 2001:470:tttt::30 remote-as 65130
  neighbor 2001:470:tttt::30 prefix-list c30-filter6-in in
  neighbor 2001:470:tttt::30 prefix-list c30-filter6-out out
  !
  neighbor 2001:470:tttt::40 remote-as 65140
  neighbor 2001:470:tttt::40 prefix-list c40-filter6-in in
  neighbor 2001:470:tttt::40 prefix-list c40-filter6-out out
  !
  address-family ipv4
    network 192.168.1.0/24
    neighbor 172.18.16.2 activate
    neighbor 172.18.65.10 activate
    neighbor 172.18.65.11 activate
    neighbor 172.18.65.12 activate
    neighbor 172.18.65.27 activate
  exit-address-family
  !
  address-family ipv6
    network 2001:470:dc8b:c000::/64
    neighbor 2001:470:tttt::27 activate
    neighbor 2001:470:tttt::30 activate
    neighbor 2001:470:tttt::40 activate
  exit-address-family
  !
  timers bgp 10 30
!
ip prefix-list clients-filter-out seq 20 permit 192.168.1.0/24
ip prefix-list clients-filter-out seq 25 deny any
!
ip prefix-list c10-filter-in seq 20 permit 172.16.10.0/24
ip prefix-list c10-filter-in seq 25 deny any
!
ip prefix-list c11-filter-in seq 20 permit 172.16.11.0/24
ip prefix-list c11-filter-in seq 25 deny any
!
ip prefix-list c12-filter-in seq 20 permit 172.16.12.0/24
ip prefix-list c12-filter-in seq 25 deny any
!
ip prefix-list c27-filter-in seq 20 permit 172.16.27.0/24
ip prefix-list c27-filter-in seq 25 deny any
!
ipv6 prefix-list c27-filter6-in seq 20 permit 2001:470:yy27::/64
ipv6 prefix-list c27-filter6-in seq 25 deny any
ipv6 prefix-list c27-filter6-out seq 20 permit 2001:470:xxxx::/64
ipv6 prefix-list c27-filter6-out seq 25 deny any
!
ipv6 prefix-list c30-filter6-in seq 20 permit 2001:470:yy30::/64
ipv6 prefix-list c30-filter6-in seq 25 deny any
ipv6 prefix-list c30-filter6-out seq 20 permit 2001:470:xxxx::/64
ipv6 prefix-list c30-filter6-out seq 25 deny any
!
ipv6 prefix-list c40-filter6-in seq 20 permit 2001:470:yy40::/48
ipv6 prefix-list c40-filter6-in seq 30 deny any
ipv6 prefix-list c40-filter6-out seq 20 permit 2001:470:xxxx::/64
ipv6 prefix-list c40-filter6-out seq 25 deny any
!
line vty
!

On an additional c27 network gateway (available over IPv4 and IPv6):

bgpd.conf

!
router bgp 65127
  bgp router-id 172.16.27.1
  !
  neighbor 172.18.65.1 remote-as 65000
  neighbor 2001:470:tttt::1 remote-as 65000
  !
  address-family ipv4
    network 172.16.27.1/24
    neighbor 172.18.65.1 activate
  exit-address-family
  !
  address-family ipv6
    network 2001:470:yy27::/64
    neighbor 2001:470:tttt::1 activate
  exit-address-family
  !
  timers bgp 10 30
!

The task is completely solved for IPv4: all gateways of additional networks receive via BGP a single route through the tunnel to the network 192.168.1.0/24 and do not see other additional networks.

For IPv6, it seems that ipv6 prefix-lists do not work at all: all gateways see all networks.
It is required that each gateway in additional networks receive only one route to the network 2001:470:xxxx::/64.