About Route Peering
Route peering is a special case of the more generic Cisco Application Centric Infrastructure (ACI) fabric as a transit use case, in which route peering enables the ACI fabric to serve as a transit domain for Open Shortest Path First (OSPF) or Border Gateway Protocol (BGP) protocols. A common use case for route peering is route health injection, in which the server load balancing virtual IP is advertised over OSPF or internal BGP (iBGP) to clients that are outside of the ACI fabric. You can use route peering to configure OSPF or BGP peering on a service device so that the device can peer and exchange routes with the ACI leaf switch to which it is connected.
The following protocols are supported for route peering:
The following figure shows how route peering is commonly deployed:
As shown in the figure, a Web server's public
IP address is advertised to an external router through a firewall by deploying a service
graph with route peering configured. You must deploy OSPF routing policies on each leg
of the firewall. This is typically done by deploying
l3extOut policies. This
enables the Web server reachability information to be advertised over OSPF through the
firewall to the border leaf switch and to the external router.
Route distribution between leaf switches in the fabric is internally accomplished over Multi-Protocol Border Gateway Protocol (MP-BGP).
For a more detailed example of the route peering topology, see Route Peering End-to-End Flow.
For more information
l3extOut policies, see the
Cisco Application Centric Infrastructure Fundamentals
Point-to-point non-broadcast mode is not supported on an Adaptive Security Appliance (ASA). You must remove the point-to-point non-broadcast mode configuration from the Application Policy Infrastructure Controller (APIC) if the configuration exists.