Hi,
I have a question about how the AAR SLA Class strict option works (vManage version 20.9, IOS-XE cEdges).
Imagine a router with 2 colors: mpls and public-internet
By using an SLA class, you want to force FTP traffic over the public-internet color.
When the SLA class fails for the public-internet color, the FTP traffic should be dropped. It should never use the mpls color, even if this one meets the SLA while the public-internet color does not.
For this requirement, is it sufficient to have an AAR policy that matches FTP traffic, and sets action preferred color public-internet + strict option? Or will this cause it to fall back to mpls if this color matches the SLA while public-internet doesn't?
The documentation (https://www.cisco.com/c/en/us/td/docs/routers/sdwan/configuration/policies/ios-xe-17/policies-book-xe/application-aware-routing.html) states the following:
" sla-class sla-class-name preferred-color color—To set a specific tunnel to use when data traffic matches an SLA class, include the preferred-color option, specifying the color of the preferred tunnel. If more than one tunnel matches the SLA, traffic is sent to the preferred tunnel. If a tunnel of the preferred color is not available, traffic is sent through any tunnel that matches the SLA class. If no tunnel matches the SLA, data traffic is sent through any available tunnel. In this sense, color preference is considered to be a loose matching, not a strict matching, because data traffic is always forwarded, whether a tunnel of the preferred color is available or not.
If no tunnel matches the SLA, data traffic is sent through any available tunnel. In this sense, color preference is considered to be a loose matching, not a strict matching, because data traffic is always forwarded, whether a tunnel of the preferred color is available or not. When no tunnel matches the SLA, you can choose how to handle the data traffic:
This would lead me to believe it would fall back to mpls. However, during my labbing, FTP seems to get blackholed when the SLA is down for public-internet, even when the SLA is still met for the mpls color.
Another way of asking the same question: can AAR by itself be used to force traffic over a specific color (and only this color)? Or do you need to accompany it with a Traffic Data policy to make sure it doesn't fall back to a color that meets the SLA Class?
Thanks.
