The sla-class and the preferred-color options tell the WAN edge router what to do when one or more colors meet the SLA requirements. However, if none of the colors meet the SLA requirements, these options do nothing, and the WAN edge router load-balances traffic across all available transports regardless of the SLA. This may not be the best in every scenario. That’s why, AAR introduced some additional actions that let us choose how to handle the data traffic when no tunnel meets SLA:
- strict
- backup-sla-preferred-color
- fallback-to-best-path