Is overlay session ID unique and persistent across the SDWAN

[tzhang_rvbd]

The Traffic Monitoring guide (https://www.cisco.com/c/en/us/td/docs/routers/sdwan/configuration/policies/ios-xe-17/policies-book-xe/traffic-flow-monitor.html#concept_wd2_zjm_5pb) states that the IPFIX template has 32-bit ingressoverlaysessionid (12432) and egressoverlaysessionid (12433) fields. Does anyone know if such session IDs are globally defined by vManage and then assigned to the individual cEdge routers? And if so, are these IDs and their assignments persistent across vManage reboots?

Thanks!

[tzhang_rvbd · Accepted solution]

After making Cflowd policy configuration changes and upgrading both vManage (to 20.10.1.1) and cEdges (to 17.10.1a) in the lab, we found the session IDs had changed in the IPFIX exports from both.routers. So it seems the session/overlay ID is unique only within the router and does not persist across reboot.

[tzhang_rvbd · Accepted solution]

Got confirmation from Cisco Support:

"Unfortunately, at this time, the Overlay Session ID information is not persistent. This decision was apparently was due to shear amount of data that would have needed to be processed."