Comment 5 for bug 1782026

@Vlad
After debugging, I found that the root cause is that the non-local subnet introduced by the routed network scenario has no interface in the local DHCP agent's namespace. Thus a KeyError will be raised when trying to get the subnet_dhcp_ip and fail to add host routes. This happens when force_metadata or enable_isolated_metadata has been set in your neutron dhcp config.

A same issue was reported in [1]. And a fix has been proposed and released in Rocky [2].

Please kindly have a try. :)

[1] https://bugs.launchpad.net/neutron/+bug/1758952
[2] https://review.openstack.org/#/c/468744