Scaling gateway to gateway traffic using flow hash

A method for improving communication between gateway devices in different datacenters using multiple processing units of a first gateway computer in a first datacenter and multiple encryption-secured tunnels, the method comprising:

• defining a plurality of encryption-secured tunnels between a first set of interfaces of the first gateway computer and a second set of interfaces of a second gateway computer in a second data center;
• for each of a plurality of processing units of the first gateway computer, assigning a unique set of encryption-secured tunnels in the plurality of encryption-secured tunnels to the processing unit, wherein the processing unit is to process data messages for its assigned set of encryption-secured tunnels;
• and
• for a data message received at the first gateway computer through a particular one of the encryption-secured tunnels, using the processing unit to which the particular encryption-secured tunnel is assigned to process the data message.

A method of configuring a first computing device to assign different processing units to use different encryption-secured tunnels to transmit data messages requiring encryption, the method comprising:

• associate a virtual tunnel interface (VTI) to each of a plurality of encryption-secured tunnels between a set of interfaces of a first and second computer;
• assign a private network address to each VTI;
• for each processing unit, (1) create a rule for a desired encryption policy in a network address rule table that identifies a routing lookup table to use for data messages matching a network-address-based rule and (2) create a custom routing lookup table that identifies the private network address of at least one VTI as a nexthop for a data message matching the network-address-based rule that points to the custom routing lookup table,
• wherein the network address rule table and the custom routing lookup table are used to select an encryption-based tunnel to transmit a data message requiring encryption.