Using a routing protocol for network port failover

A computer system for using an OSI (open systems interconnection) model layer-three protocol for network port failover in a single network stack environment having a single default route, comprising:

• a processor;
• a plurality of network ports;
• and
• a computer storage medium that stores computer-executable instructions that are executable by the processor to cause the computer system to at least:
• identify a plurality of interfaces configured at a network stack that does not perform reverse path forwarding, including identifying at least:
• a first interface provided by the network stack as a loopback interface, and that is assigned a first IP (internet protocol) address corresponding to a first IP subnet,
• a second interface provided by the network stack as an interface to a first network port of the plurality of network ports, and that is assigned a second IP address corresponding to a second IP subnet that is different than the first IP subnet, and
• a third interface provided by the network stack as an interface to a second network port of the plurality of network ports, and that is assigned a third IP address corresponding to a third IP subnet that is different than each of the first IP subnet and the second IP subnet;
• configure an OSI model layer-three routing protocol to communicate over the second interface with a first port at one or more remote network devices, and to communicate over the third interface with a second port at one or more remote network devices;
• announce, to the one or more remote network devices, a route comprising the first IP address;
• configure a default route of the network stack to egress IP packets via the second interface;
• after configuring the network stack to route IP packets via the second interface, determine, based on the OSI model layer-three routing protocol, that there is a forwarding failure associated with the second interface;
• and
• based on determining that there is a forwarding failure associated with the second interface, configure the default route of the network stack to egress IP packets via the third interface.

A computer program product comprising a hardware storage medium that stores computer-executable instructions that are executable by a processor to cause a computer system to use a routing protocol for network port failover in a single network stack environment having a single default route, the computer-executable instructions including instructions that are executable by the processor to cause the computer system to at least:

• identify a plurality of interfaces configured at a network stack that does not perform reverse path forwarding, including identifying at least:
• a first interface provided by the network stack as a loopback interface, and that is assigned a first IP (internet protocol) address corresponding to a first IP subnet,
• a second interface provided by the network stack as an interface to a first network port of a plurality of network ports of the computer system, and that is assigned a second IP address corresponding to a second IP subnet that is different than the first IP subnet, and
• a third interface provided by the network stack as an interface to a second network port of the plurality of network ports, and that is assigned a third IP address corresponding to a third IP subnet that is different than each of the first IP subnet and the second IP subnet;
• configure a routing protocol to communicate over the second interface with a first port at one or more remote network devices, and to communicate over the third interface with a second port at one or more remote network devices;
• announce, to the one or more remote network devices, a route comprising the first IP address;
• configure a default route of the network stack to egress IP packets via the second interface;
• after configuring the network stack to route IP packets via the second interface, determine, based on the routing protocol, that there is a forwarding failure associated with the second interface;
• and
• based on determining that there is a forwarding failure associated with the second interface, configure the default route of the network stack to egress IP packets via the third interface.