Comment 6 for bug 1858132

Finally have a re-creator test.

I can confirm that classic charms conform to the expectation:

A snippet from keystone's haproxy.cfg

frontend tcp-in_public-port
    bind *:5000
    bind :::5000
    acl net_172.20.0.36 dst 172.20.0.36/255.255.255.0
    use_backend public-port_172.20.0.36 if net_172.20.0.36
    acl net_172.16.0.35 dst 172.16.0.35/255.255.255.0
    use_backend public-port_172.16.0.35 if net_172.16.0.35
    acl net_192.168.100.29 dst 192.168.100.29/255.255.255.0
    use_backend public-port_192.168.100.29 if net_192.168.100.29
    default_backend public-port_192.168.100.29

backend public-port_172.20.0.36
    balance leastconn
    server keystone-0 172.20.0.36:4990 check
    server keystone-1 172.20.0.6:4990 check
    server keystone-2 172.20.0.15:4990 check

backend public-port_172.16.0.35
    balance leastconn
    server keystone-0 172.16.0.35:4990 check
    server keystone-1 172.16.0.41:4990 check
    server keystone-2 172.16.0.21:4990 check

backend public-port_192.168.100.29
    balance leastconn
    server keystone-0 192.168.100.29:4990 check
    server keystone-1 192.168.100.21:4990 check
    server keystone-2 192.168.100.12:4990 check

Digging into the root cause now.