[Mainline-Build 2672]: IPv6-not able to allocate ipv6 floating IP

[alok kumar]

IPv6 FIP allocation throws error - "Error: Virtual-Network(['default-domain', 'admin', 'vn3']) has exhausted subnet(all)".
This is through contrail UI, not yet tried with script.

root@nodeg18:/var/log/nova# neutron net-show vn3
+-------------------------+-------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-------------------------+-------------------------------------------------------------------------------------------------------------------------+
| admin_state_up | True |
| contrail:fq_name | default-domain |
| | admin |
| | vn3 |
| contrail:instance_count | 0 |
| contrail:subnet_ipam | {"subnet_cidr": "2002:8192:5666:5::/64", "ipam_fq_name": ["default-domain", "default-project", "default-network-ipam"]} |
| id | 4ce9de5c-b540-4e95-a337-a1948b92efbc |
| name | vn3 |
| router:external | False |
| shared | False |
| status | ACTIVE |
| subnets | 9f4e61a5-0df7-4d2f-bc9b-0d7bdc7da9ae |
| tenant_id | 7346470257d14b64af22ff586bba1bc1 |
+-------------------------+-------------------------------------------------------------------------------------------------------------------------+

setup info:

env.roledefs = {
    'all': [host1,host2,host3,host4],
    'cfgm': [host1],
    'openstack':[host2],
    'control': [host1,host2],
    'compute': [host3,host4],
    'collector': [host1,host2],
    'webui': [host1],
    'database': [host1],
    'build': [host_build],
}

env.hostnames = {
    'all': ['nodec64', 'nodeg18', 'nodec62', 'nodec12']
}