Dual-Stack BGP

[Marcm19921]

Trying to learn BGP and I'm attempting to lab up some Multiprotocol BGP and I'm having a problem because my Routers are only sharing their IPv6 routes, not the IPv4 routes. Can someone please let me know if I've misconfigured something? 

R1

int f1/0

no shut 

description IXP 

ip address 172.16.120.221 255.255.255.0

ipv6 address 2001:A120::21/64

ipv6 address FE80:2100::1 link-local

ip route 172.21.0.0 255.255.0.0 null0

ipv6 route 2001:2100::/48 null0 

router bgp 21

bgp router-id 172.16.120.221

no bgp default ipv4 

no bgp default ipv4-unicast 

neighbor 172.16.120.22 remote-as 22

neighbor 172.16.120.23 remote-as 23

neighbor 2001:A120::22 remote-as 22

neighbor 2001:A120::23 remote-as 23

address-family ipv4

neighbor 172.16.120.22 activate

neighbor 172.16.120.23 activate

network 172.21.0.0 mask 255.255.0.0

exit 

address-family ipv6 

neighbor 2001:A120::22 activate

neighbor 2001:A120::23 activate

network 2001:2100::/48




R2

int f1/0

no shut 

description IXP 

ip address 172.16.120.222 255.255.255.0

ipv6 address 2001:A120::22/64

ipv6 address FE80:2200::1 link-local

ip route 172.22.0.0 255.255.0.0 null0

ipv6 route 2001:2200::/48 null0 

router bgp 22

bgp router-id 172.16.120.222

no bgp default ipv4 

no bgp default ipv4-unicast 

neighbor 172.16.120.21 remote-as 21

neighbor 172.16.120.23 remote-as 23

neighbor 2001:A120::21 remote-as 21

neighbor 2001:A120::23 remote-as 23

address-family ipv4

neighbor 172.16.120.21 activate

neighbor 172.16.120.23 activate

network 172.22.0.0 mask 255.255.0.0

exit 

address-family ipv6 

neighbor 2001:A120::21 activate

neighbor 2001:A120::23 activate

network 2001:2200::/48

[Harold Ritter · Accepted solution]

Hi @Marcm19921 ,

I think you use the wrong IPv4 peer addresses. Shouldn't it be 172.16.120.221 and 172.16.120.222 in place of 172.16.120.21 and 172.16.120.22?

Also, you can use the

show bgp ipv4 unicast

to verify that the ipv4 session is up and working as expected. 

Regards,