Failback on Primary vSmart controller

[ravi310859]

Hi 

I need to know in case of failover from primary to secondary vSmart node. What would be the behavior If primary vSmart would comeup , would it be remain on secondary node or it will come back to primary node. Does these controller support Preempt. 

Note: I am considering that I have configured the controller group on each VSmart.

Thanks & Regards

Ravi

[Kanan Huseynli]

Hi,

here is what happens in normal SD-WAN deployment:

• each vSmart has connection vBond
• each router has connection to each vSmart (default, 2 per interface) - number of connections depends on max-control-connection per interface command) ; the WAN Edge router control connections will be hashed to a subset of vSmart controllers to choose vSmarts
• each router has OMP peering to each vSmart (default, 2 per router) - number of peering depends on max-omp-sessions
• there is full mesh OMP peering between vSmarts (over DTLS/TLS)

See example, in case of max-omp-sessions to be 2 and max-control-connection to be 2 (this is per interface command). Result is, 2 omp peering, 2*2=4 control connections in case of 2 local TLOC on router (picture from CVD, link is shared).

https://www.cisco.com/c/en/us/td/docs/solutions/CVD/SDWAN/cisco-sdwan-design-guide.html#vSmartController

"If one of the vSmart controllers fails, the other vSmart controllers seamlessly take over handling control of the network. The remaining vSmart controllers are able to work with Cisco IOS XE SD-WAN devices and Cisco vEdge devices joining the network and are able to continue sending route updates to the routers. As long as one vSmart controller is present and operating in the domain, the Cisco SD-WAN network can continue operating without interruption."

https://www.cisco.com/c/en/us/td/docs/routers/sdwan/configuration/ha-scaling/vedge-20-x/high-availability-book-vedge/m-high-availability-and-scaling-vedge.html#concept_fpj_v53_x3b

Regarding, primary backup, if you mean configuring two groups in order with different controller-group-id, then when router can not connect to any of vsmart from primary controller-group, it connects to the secondary one and when primary is available it re-connects to the primary.

https://www.cisco.com/c/en/us/td/docs/routers/sdwan/configuration/ha-scaling/vedge-20-x/high-availability-book-vedge/m-high-availability-and-scaling-vedge.html#concept_tg1_wxy_4lb

[MHM Cisco World]

you ask about preempt like found in HSRP, I will check it.
update you soon

[MHM Cisco World]

friend did you config vSmart in same group or different ?
did you specify max controller connection in group ?