Comment 3 for bug 2004004

Hello Rodolfo,

openstack subnet show xxxxxxxxx -c gateway_ip -c allocation_pools -c cidr
+------------------+-------------------------------+
| Field | Value |
+------------------+-------------------------------+
| allocation_pools | 100.100.100.42-100.100.100.46 |
| cidr | 100.100.100.40/29 |
| gateway_ip | 100.100.100.33 |
+------------------+-------------------------------+

openstack subnet show yyyyyyyyy -c gateway_ip -c allocation_pools -c cidr
+------------------+-------------------------------+
| Field | Value |
+------------------+-------------------------------+
| allocation_pools | 100.100.100.34-100.100.100.38 |
| cidr | 100.100.100.32/29 |
| gateway_ip | 100.100.100.33 |
+------------------+-------------------------------+

You are right, the GW is out of the subnet xxxxxxxxx BUT this is not a problem from a technical point of view (with L3-Agent and Keepalived).
Two options:
A: The Linux kernel is able to route packages to that GW with a "onlink" route.
B: Keepalived (in rocky) is configured (by the l3 agent) to add a net route:

    virtual_routes {
        0.0.0.0/0 via 100.100.100.33 dev qg-7b9963a7-72
        100.100.100.32/29 dev qg-7b9963a7-72 scope link <<<<<<<<<<<<<
    }

The only problem with option B is the "order". The net route has to exist before the default route is added.

If this is not possible anymore with neutron >= 18.x.x how to do the following:

1. Admin: create a public network
2. Admin: create a subnetpool for this network
3. User: create a subnet from this subnetpool in this public network to get a "dedicated" public IP range that can be used for floating IPs and routers.

When the "physical" network was created, there is only ONE gateway IP. This single GW IP has to be used for each subnet, right?

All the best,
Florian