|Question||How can excessive mDNS traffic be throttled using global credits in Airgroup implementation? How is it configured?|
|Environment||This article applies to Aruba Mobility Controllers running ArubaOS version 220.127.116.11 with Airgroup feature enabled.|
In an AirGroup network, AirGroup devices generate excess mDNS query and response packets and excessive mDNS packets can impact the performance of AirGroup. Throttling mechanism such as "credit values" has been added to rate limit the number of mDNS packets processed by the controller.
Controller assigns separate credit values to query and response packets.Credit is decremented by one, when a query or response packet is processed by controller. Controller will drop any query/response packets when the corresponding credit is zero. The controller rejects any packets beyond this credit limit which renews every 15 seconds. The renewal time is not a configurable parameter.
The credit values are local to a airgroup controller and can be seen using the command:
"Show airgroup global-credits"
NOTE: The counters under Global Credits – Current will display the remaining credits at that point of time.
Based on the controller model, the global credits are defined by default, which is the number of mDNS queries or responses that needs to be processed. But, with the given load on the controller administrator can increase or decrease the global credits.
Below screenshot shows how the global credits can be configured:
(Aruba-3400) (Config)#airgroup global-credits <no. of queries> <no of responses>
NOTE: The minimum value for queries and responses is 15 and the maximum is 15000.