Openstack Create instance error: Failed to allocate the network(s) with error No fixed IP addresses available for network

The log indicates that sending HDR request to TGT fails, so there is a problem with tgtd service [tgtd iSCSI target daemon]. Tgtd iSCSI target daemon means that tgtd is the background service of iSCSI target, that is, the daemon. Execute the command systemctl status tgtd and find that the service is in the disabled state, so start the service systemctl start tgtd to solve the problem