Instance Failing to Initialize Networking (Unable to Receive DHCP Response)

Problem

• Instance is failing to boot or be reachable.
• No DHCP reply is received.
• DHCP request is observed on both the physical (e.g. bond0) interface of both the hypervisor, and designated DHCP agent host(s).

Environment

• Platform9 Managed OpenStack - All Versions

Cause

Either on which the hypervisor on which the instance resides, or one of the associated hosts of the designated DHCP agents for the given network, the Linux/OVS bridge which is defined as part of the bridge_mappings variable in /opt/pf9/etc/pf9-neutron-ovs-agent/ml2.conf is either invalid, or the bridge has no associated physical interface (e.g. bond0).

Resolution

1. Ensure that bridge_mappings in the /opt/pf9/etc/pf9-neutron-ovs-agent/ml2_conf.ini configuration file on the affected host (whether the hypervisor, or DHCP host) has the correct physical interface name specified.
2. If it has been modified, restart the pf9-neutron-ovs-agent service.
3. Otherwise, ensure the physical interface is added to the specified interface, e.g.

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ovs-vsctl add-port br-pf9 bond0