Aggregate export flag under L3Out EXT EPG in ACI

[SandevChopra07800]

Hi fellow enthusiasts, I came across a customer requirement to use the 0.0.0.0/0 with the aggregate export flag under the External EPG of a L3Out. Now I know this will advertise everything out, but does it also advertise the transit routes that the ACI learnt from other L3Outs? 

[M02@rt37]

Hello @SandevChopra07800 

If the export control policy is configured to include the transit routes learned from other L3Outs, then those routes will be advertised along with the default route.

[SandevChopra07800]

there only will be a quad-zero with the aggregate flags as shown in the below screenshot - 

Will it still advertise transit routes + default R + Local BDs ? 

[M02@rt37]

@SandevChopra07800 

The advertisement of transit routes would depend on the export control policies and routing configurations. If your export control policies allow the advertisement of transit routes, and if your routing protocol (e.g., BGP) is configured to advertise those routes, then they may also be included in the advertisements.

By default, local BD routes are not advertised to the external network unless explicitly configured to do so. If you want to advertise local BD routes, you would need to include them in the export control policies.

[SandevChopra07800]

There are no explicit export control policies/Route-maps configured anywhere. The BD subnets are associated with this L3Out, so coming back to my Q, will this quad-zero with aggregated flag advertise the transit routes? Simple yes or no?