Q on ACI route summarization

[SandevChopra07800]

Hi, we have ACI multi-site setup and thinking to use OSPF route-summarization towards the external Core Router. The L3Out and External EPG are local to the site (not stretched). Let's say we want to summarize all the 10.x.x.x.x/x subnets to the classfull level - 10.0.0.0/8, will the fabric advertise the summary route as well as its local BD subnets which are associated with that site-local L3Out? 

[Robert Burns]

Routes can be summarized applied to the L3out ExtEPG.  If you apply a summary route, only that will be advertised externally and not the individual BD subnets.
https://www.cisco.com/c/en/us/td/docs/dcn/aci/apic/5x/l3-configuration/cisco-apic-layer-3-networking-configuration-guide-52x/route-summarization-layer3-config-52x.html 

Robert

[Robert Burns · Accepted solution]

Example.

Without Summary route (Export Route defined), BD subnets get advertised by their prefix:

Now with a Summary Route:

Robert

[SandevChopra07800]

Hey Robert, what about host-based routes for the stretched BDs. Does those get affected as well?