Solution

R3

router bgp 65413

add ipv4

nei 2.2.2.2 allowas-in

nei 4.4.4.4 allowas-in

add ipv6

nei 2001:db8:4:4:4::4 allowas-in

end

copy run start

=======================

R2

router bgp 65413

nei 1.1.1.1 as-override

nei 3.3.3.3 as-override

end

copy run start

=======================

R3

router bgp 65413

nei 10.3.4.2 remot 65412

nei 2001:db8:3:4::2 remot 65412

nei 2001:db8:4:4:4:4::4 remot 65412

nei 2001:db8:4:4:4:4::4 ebgp-multihop 10

add ip4

nei 10.3.4.2 act

ex

add ipv6

nei 2001:db8:4:4:4:4::4 activate

nei 2001:db8:4:4:4:4::4 ebgp-multihop 10

nei 2001:db8:3:4::2 act

end

copy run start

===================

R4

router bgp 65412

nei 10.3.4.1 remot 65413

nei 2001:db8:3:3:3:3::3 remot 65413

nei 2001:db8:3:3:3:3::3 ebgp-multihop 10

nei 2001:db8:3:4::1 remot 65413

add ipv4

nei 10.3.4.1 remot act

nei 10.3.4.1 prefix-limit 10

add ipv6

nei 2001:db8:3:3:3:3::3 activate

nei 2001:db8:3:3:3:3::3 ebgp-multihop 10

nei 2001:db8:3:3:3:3::3 prefix-limit 10

nei 2001:db8:3:4::1 activate

nei 2001:db8:3:4::1 prefix-limit 10

end

copy run start