Protection against rule map update attacks

1. A method to manage replacement of routing rules for use by a routing device, the method comprising:

receiving a request to replace one or more active rules in the routing device with one or more stored rules, each of the one or more active rules and each of the one or more stored rules specifying a routing rule that specifies how to route packets within a network, wherein the stored rules are not actively being used by the routing device for routing;

determining a number of active rule replacements for the routing device;

determining that the number of the active rule replacements exceeds a threshold; and

in response to determining that the number of the active rule replacements exceeds the threshold, denying the request to replace the one or more active rules in the routing device for a period of time until the routing device is determined to be capable to process the request to replace the one or more active rules.

2. The method of claim 1 , wherein determining the number of the active rule replacements for the routing device comprises determining the number of the active rule replacements for the routing device that occur within a time window.

3. The method of claim 2 , wherein a duration of the time window is changed based at least in part on a detected performance of the routing device.

4. The method of claim 1 , wherein determining the number of the active rule replacements for the routing device comprises determining the number of the active rule replacements for the routing device within a time window for at least one user of the routing device that includes at least one active rule in the routing device.

5. The method of claim 1 , wherein the threshold is based at least in part on a storage capacity of a memory that stores the one or more active rules for the routing device.

6. The method of claim 1 , wherein the threshold is based at least in part on a detected performance of the routing device that includes determining a number of rules the routing device can service under current network conditions.

7. The method of claim 1 , wherein the threshold is dynamically changed during an operation of the routing device.

8. The method of claim 1 , further comprising monitoring the routing device to detect that the routing device is broadcasting packets and, in response to the routing device broadcasting the packets, changing the threshold to a lower value.

9. A system, comprising:

a routing device configured to route packets within a network based at least in part on active rules stored within a memory of the routing device; and

a monitoring device coupled to the routing device, the monitoring device configured to:

receive a request to replace an active rule in the routing device with a stored rule,

determine that a number of rule replacements made by the routing device within a specified period of time exceeds a threshold, and

in response to the determination that the number of the rule replacements exceeds the threshold, deny the request to replace the active rule in the routing device with the stored rule for a period of time until the routing device is determined to be capable to process the request to replace the one or more active rules.

10. The system of claim 9 , wherein the routing device further comprises one or more counters coupled to the memory that are configured to count the number of the rule replacements made by the routing device within the specified period of time.

11. The system of claim 9 , wherein the routing device further comprises one or more counters coupled to the memory that are configured to count the number of the rule replacements made within the specified period of time.

12. The system of claim 9 , wherein the monitoring device further comprises a threshold ditherer that is configured to dynamically change the threshold.

13. The system of claim 9 , wherein the specified period of time is a rolling time window that is based at least in part on a time to replace the active rules in the memory of the routing device.

14. The system of claim 9 , wherein the threshold is based at least in part on one or more of:

a number of active rules stored in the memory of the routing device or a performance of the routing device.

15. A non-transitory computer-readable storage medium that includes computer-executable instructions stored thereon which, in response to execution by a computer, cause the computer to:

determine a number of active rule replacements for a routing device within a rolling time window, wherein the routing device is configured to route packets within a network according to active rules stored within a memory of the routing device;

determine that the number of the active rule replacements within the rolling time window exceeds a threshold; and

in response to the determination that the number of the active rule replacements exceeds the threshold, deny a request to replace one or more of the active rules stored within the memory of the routing device for a period of time until the routing device is determined to be capable to process the request to replace the one or more active rules.

16. The non-transitory computer-readable storage medium of claim 15 , wherein the threshold is set based at least in part on a number of the active rules stored in the memory of the routing device.

17. The non-transitory computer-readable storage medium of claim 15 , comprising further instructions to dynamically change a duration of the rolling time window.