Veth paire cant ping bridge IP

[elgamal2020]

In the demo in minute 13 , you show that you are able to ping the bridge IP from the interfaces while I cant

 demobr1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 42:51:a7:b9:ce:c0 brd ff:ff:ff:ff:ff:ff
    inet 172.16.0.1/24 scope global demobr1
       valid_lft forever preferred_lft forever
    inet6 fe80::b027:f8ff:fe08:b93d/64 scope link
       valid_lft forever preferred_lft forever
10: pair1-b@pair1-a: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 7a:52:7e:2e:4c:1e brd ff:ff:ff:ff:ff:ff
    inet 172.16.0.2/24 scope global pair1-b
       valid_lft forever preferred_lft forever
    inet 172.16.0.3/24 scope global secondary pair1-b
       valid_lft forever preferred_lft forever
    inet6 fe80::7852:7eff:fe2e:4c1e/64 scope link
       valid_lft forever preferred_lft forever
11: pair1-a@pair1-b: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master demobr1 state UP group default qlen 1000
    link/ether d6:28:8b:70:62:fe brd ff:ff:ff:ff:ff:ff
    inet6 fe80::d428:8bff:fe70:62fe/64 scope link
       valid_lft forever preferred_lft forever

so I can ping it from the host

gml@ovn:~/netdevops-live-0213$ ping 172.16.0.1
PING 172.16.0.1 (172.16.0.1) 56(84) bytes of data.
64 bytes from 172.16.0.1: icmp_seq=1 ttl=64 time=0.035 ms
64 bytes from 172.16.0.1: icmp_seq=2 ttl=64 time=0.067 ms
^C
--- 172.16.0.1 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1013ms

but not from the veth paris

gml@ovn:~/netdevops-live-0213$ ping 172.16.0.1 -I pair1-a
ping: Warning: source address might be selected on device other than pair1-a.
PING 172.16.0.1 (172.16.0.1) from 192.168.56.198 pair1-a: 56(84) bytes of data.
^C
--- 172.16.0.1 ping statistics ---
173 packets transmitted, 0 received, 100% packet loss, time 176108ms

gml@ovn:~/netdevops-live-0213$ ping 172.16.0.1 -I pair1-b
PING 172.16.0.1 (172.16.0.1) from 172.16.0.2 pair1-b: 56(84) bytes of data.


^C^C
--- 172.16.0.1 ping statistics ---
5 packets transmitted, 0 received, 100% packet loss, time 4075ms

Thanks a lot