In-service configuration upgrade using virtual machine instances

A network device comprising at least one processor configured to operate as:

• a routing component;
• a first virtual machine running on the routing component, wherein the first virtual machine is configured to execute a first operating system, wherein the first operating system controls a communication session between the network device and a second network device, and controls an in-service configuration update (ISCU) of the routing component;
• and
• a second virtual machine running on the routing component, wherein, in response to receiving an ISCU request with the first virtual machine to update the first operating system for the routing component, the first virtual machine requests initialization of the second virtual machine on the routing component of the network device, requests installation of a second operating system on the second virtual machine running on the routing component of the network device, wherein the second operating system is different than the first operating system, transfers control of the routing communication session from the first operating system on the first virtual machine to the second operating system on the second virtual machine running on the routing component of the network device while a forwarding component of the network device continues to forward data packets from the network device to the second network device, and requests shut down of the first virtual machine after control of the routing communication session is transferred to the second operating system on the second virtual machine.

A non-transitory, computer-readable storage medium comprising instructions that cause one or more programmable processors to:

• on a routing component of a network device, run a first virtual machine executing a first operating system that controls a routing communication session between the network device and a second network device, and controls an in-service configuration update (ISCU) of the routing component of the network device;
• in response to receiving an ISCU request with the first virtual machine to update the first operating system for the routing component, initialize a second virtual machine on the routing component of the network device;
• install a second operating system on the second virtual machine running on the routing component of the network device, wherein the second operating system is different than the first operating system;
• transfer control of the routing communication session from the first operating system on the first virtual machine to the second operating system on the second virtual machine running on the routing component of the network device while continuing to forward data packets from the network device to the second network device;
• and
• after transferring control of the routing communication session to the second operating system on the second virtual machine, shut down the first virtual machine.