High availability of host data path with tunneling in software defined networks

A system comprising:

• an active network appliance;
• and
• a backup network appliance;
• the system configured to perform operations comprising:
• receiving a packet associated with a communication session of a VM in a software defined network (SDN), wherein:
• the active network appliance and backup network appliance are configured to process connections in the SDN;
• the active network appliance is configured to actively process connections, and the backup network appliance maintains connection states such that the backup network appliance can actively process connections in response to a failure of the active network appliance;
• network interfaces from the VM are provisioned on multiple network interface devices at each of the network appliances;
• identifying an active network interface device on the active network appliance associated with the communication session, wherein a backup network interface device on the backup network appliance is also associated with the communication session;
• forwarding the packet to the active network interface device for processing the packet associated with the communication session;
• and
• in response to determining that the active network interface device has failed, causing subsequent packets associated with the communication session to be routed to the backup network interface device associated with the communication session, thereby allowing the backup network interface device to maintain connection state information and avoid performing new connection state processing for the communication session.

A network appliance comprising a plurality of network interface devices, the network appliance configured to perform operations comprising:

• receiving a packet associated with a communication session of a VM of a software defined network (SDN), wherein:
• the network appliance is configured to process connections in the SDN,
• the network appliance includes an active network interface device communicatively coupled to a backup network interface device that maintains connection states such that the backup network interface can actively process connections in response to a failure of the active network interface, and
• network interfaces from the VM are provisioned on multiple network interface devices at the network appliance;
• identifying an active network interface device of the network appliance that is associated with the communication session, wherein a backup network interface device of the network appliance is also associated with the communication session;
• forwarding the packet to the active network interface device for processing the packet associated with the communication session;
• and
• in response to determining that the active network interface device has failed, causing subsequent packets associated with the communication session to be routed to the backup network interface device associated with the communication session, thereby allowing the backup network interface device to maintain connection state information and avoid performing new connection state processing for the communication session.