AAR - Application Probe Class - BFD question

[jgeralsky]

Hello, 

Please check the attachment for current settings, where Application Probe Class is not enabled yet. 

I have simple question about BFD. 

How many BFD packets will be in the output "show sdwan app-route stats summary" TOTAL PACKETS, when I enable Application Probe Class for SLA class Bulk-Data_wide, Video_wide, Voice_wide ? 

Please note, there is a formula in Cisco documentation : "When BFD packets are sent with app-probe-class along with SLA class, the BFD packets are sent for each SLA app-probe-class separately in a round-robin manner."

https://www.cisco.com/c/en/us/td/docs/routers/sdwan/configuration/policies/ios-xe-17/policies-book-xe/application-aware-routing.html#Cisco_Concept.dita_9a411407-294b-4326-a494-03e9c50432b7:~:text=When%20BFD%20packets%20are%20sent%20with%20app%2Dprobe....

I am only curios about the amount of BFD packets. Nothing more.

Many thanks,

Jan

[Dan Frey]

The BFD probes are set at multiplier 3 and poll interval of 180 seconds.   The first table shows mpls transport with 7 classes.  There is the default class(None) along with user configured classes of BE,AF1,AF2,AF3,AF4,EF.   Add up all the probes on this mpls -> private transport for each index which roughly comes out to 28 or 29 probles on each index0 and there are 7 index zeros which comes out to about 200 probes total for index0 on the first table .   The second table is another transport that only has the default BFD probe and no app-probe-class associated for a total of 200 bfd probes per index.   

[jgeralsky]

Hello Dan,

thank you for the reply. 

 I checked your output.

If you use an "app probe class", then you send fewer BFD packets overall, because BFD packets are sent for each SLA app-probe class separately in a round-robin manner—correct?

I'm trying to figure out if there's any additional BFD overhead when using app probe classes.

Many thanks for the feedback.