I have been looking to allow multiple fixed-ip on a single vm port, and I was running into the error message indicating reaching max limit (1), so after poking around I discovered max_fixed_ips_per_port, which I see some discussions about it being removed from openstack but not sure where that stands.
Having said that, this is not a "production system" so I modified max_fixed_ips_per_port from 1 to 5 and restarted neutron-server on each controller, and on the surface this seems to work fine as long as the subnet being specified does not have dhcp enabled, if dhcp is enabled it will add the IP however bail out during dhcp process and leave you in an inconsistent state where openstack shows the IP assigned but some other neutron/nsx steps have not taken place so the traffic is still filtered inside nsx/hypervisor somewhere.
From /etc/neutron/neutron.conf on the controllers:
# Maximum number of fixed ips per port. This option is deprecated and will be
# removed in the N release. (integer value)
# This option is deprecated for removal.
# Its value may be silently ignored in the future.
max_fixed_ips_per_port = 1
If there is some other way I should be trying to accomplish this I would love to hear, but this is a specific situation where I have vm's that attach to a vlan based network which has an external physical router, and they need to allocate multiple public ip's directly on the single interface, floating ip's / nat will not work in this situation, I will use the topology of floating ip's etc as I onboard new projects where it is appropriate.
SO, long story short, is there an appropriate way for me to make this modification to neutron.conf in a way that it will not be overwritten during future updates etc, should I be modifying the ansible template on the management -server?
Thanks!