Route selection using cumulative cost

Patent metadata

Field	Value
Publication number	US-11398973-B2
Application number	US-201916536028-A
Country	US
Kind code	B2
Filing date	Aug 8, 2019
Priority date	Sep 26, 2018
Publication date	Jul 26, 2022
Grant date	Jul 26, 2022

Abstract

Examples include determining a first hop for a preferred route from a networking device to a destination device, calculating a cumulative cost for the preferred route based on a cost of the first hop and an original cost of the preferred route, determining whether a secondary route is available, and, in response to a determination that the secondary route is available, determining a first hop in the secondary route. Examples also include determining a cost of the first hop in the secondary route, determining a new route from the networking device to the destination computing device based on the cumulative cost of the preferred route and the cost of the first hop in the secondary route, and entering the new route into a forwarding data structure of the networking device.

First claim

We claim:

1. A non-transitory machine-readable storage medium comprising instructions, that when executed, cause a processing resource to:
determine a first hop for a preferred route from a networking device to a destination computing device;
determine whether the first hop for the preferred route is directly connected to the networking device;

based on a determination that the first hop for the preferred route is not directly connected to the networking device, determine a second hop for the preferred route;
determine a cost for the second hop for the preferred route;
determine a cumulative cost for the preferred route based on a cost of the first hop, the cost for the second hop and an original cost of the preferred route;
determine whether a secondary route from the networking device to the destination computing device is available;
in response to a determination that the secondary route is available, determine a first hop in the secondary route;
calculate a cost of the first hop in the secondary route;
determine a new route from the networking device to the destination computing device based on the cumulative cost of the preferred route and the cost of the first hop in the secondary route;

enter the new route into a forwarding data structure of the networking device,
calculate the cumulative cost for the preferred route based on the cost for the second hop.

2. The non-transitory machine-readable storage medium of claim 1 , wherein the instructions to determine a new route comprises comparing the cumulative cost of the preferred route to the cost of the first hop in the secondary route.

3. The non-transitory machine-readable storage medium of claim 1 , wherein the determination of the availability of the secondary route is based on a routing information base (RIB).

4. The non-transitory machine-readable storage medium of claim 1 , wherein the forwarding data structure is a Forward Information Base (FIB).

5. The non-transitory machine-readable storage medium of claim 1 , comprising instructions, that when executed, cause the processing resource to:
determine whether the first hop for the secondary route is directly connected to the networking device;
based on a determination that the first hop for the secondary route is not directly connected to the networking device, determine a second hop for the secondary route;
determine a cost for the second hop for the secondary route;
wherein the determination of the new route is based on the cost for the second hop of the secondary route.

6. The non-transitory machine-readable storage medium of claim 1 , wherein the preferred route comprises an original hop and the first hop is between the original hop and the networking device.

7. The non-transitory machine-readable storage medium of claim 6 , wherein the original cost of the preferred route comprises an administrative distance of an original pathway to the original hop.

8. A networking device comprising:
a memory to store a forwarding data structure;

a routing engine:
to determine a preferred route for a packet from the networking device to a destination computing device, wherein the preferred route comprises an original cost;
to determine a first hop for the preferred route, wherein the first hop comprises a cost;
to determine whether the first hop for the preferred route is directly connected to the networking device;
to determine a second hop for the preferred route based on a determination that the first hop is not directly connected to the networking device;
to determine a cost for the second hop for the preferred route;
to calculate a first cumulative cost for the preferred route based on the original cost, the cost of the first hop and the cost of the second hop;
to determine whether a secondary route for the packet from the networking device to a destination computing device is available;
to determine a first hop in the secondary route based on a determination that a secondary route is available;
to determine a cost of the first hop in the secondary route; and
to determine a new route to the destination device from the networking device based on the first cumulative cost of the preferred route and the cost of the first hop in the secondary route; and
a forwarding engine to update the forwarding data structure with the new route.

9. The networking device of claim 8 , wherein the preferred route comprises an original hop and the first hop is a hop between the original hop and the networking device.

10. The networking device of claim 8 , wherein the routing engine is:
to determine whether the first hop in the secondary route is directly connected to the networking device;
to determine a second hop in the secondary route based on a determination that the first hop is not directly connected to the networking device;
to determine a cost for the second hop in the secondary route;
wherein the determination of the new route is based on the cost for the second hop in the secondary route.

11. The networking device of claim 8 , wherein the memory is to store a routing data structure, wherein the determination of the first hop for the preferred route is based on the routing data structure.

12. A method comprising:
determining, by a processing resource, a preferred route from a networking device to a destination computing device, wherein the preferred route is a static route;
determining, by the processing resource, a first hop for the preferred route;
determining, by the processing resource, whether the first hop for the preferred route is directly connected to the networking device; and
based on a determination that the first hop is not directly connected, determining, by the processing resource, a second hop of the preferred route;
calculating, by the processing resource, a first cumulative cost for the preferred route;
determining, by the processing resource, a secondary route from the networking device to the destination computing device;
determining, by the processing resource, a first hop in the secondary route;
calculating, by the processing resource, a second cumulative cost for the secondary route;
determining, by the processing resource, a new route based on a comparison of the first cumulative cost to the second cumulative cost; and
programming, by the processing resource, the new route into a forwarding data structure of the networking device.

13. The method of claim 12 , wherein the preferred route has an original cost; and
wherein the step of determining a first cumulative cost is based on the original cost.

14. The method of claim 12 , comprising:
determining, by the processing resource, a cost for the second hop of the preferred route;
wherein the first cumulative cost is determined based on the cost for the second hop of the preferred route.

15. The method of claim 12 , comprising:
determining, by the processing resource, a cost for a second hop of the secondary route;
wherein the second cumulative cost is determined based on the cost for the second hop of the secondary route.

16. The method of claim 12 , wherein the secondary route is a static route.

17. A method comprising:
determining, by a processing resource, a preferred route from a networking device to a destination computing device, wherein the preferred route is a static route;
determining, by the processing resource, a first hop for the preferred route;
determine whether the first hop for the preferred route is directly connected to the networking device;
based on a determination that the first hop for

Assignees

• Hewlett Packard Entpr Dev Lp

Inventors

• Raj Anil
• Nair Anoop Govindan
• Devarajan Venkatavaradhan

Classifications

• H04L45/14

  Routing performance; Theoretical aspects · CPC title

• H04L45/021

  Ensuring consistency of routing table updates, e.g. by using epoch numbers · CPC title

• H04L45/122 Primary

  by minimising distances, e.g. by selecting a route with minimum of number of hops · CPC title

• H04L45/20

  Hop count for routing purposes, e.g. TTL · CPC title