Which two statements about import and export route control in an ACI fabric are true? (Choose two.)
Click on the arrows to vote for the correct answerA. B. C. D. E.
In an ACI fabric, import and export route control can be used to control the routes learned from external networks via various protocols such as BGP, OSPF, and EIGRP.
A. The statement "Prefixes learned from BGP L3outs cannot be filtered inbound" is true. When prefixes are learned from external BGP L3outs, inbound route filtering cannot be applied due to BGP's loop prevention mechanisms. Instead, route maps can be used to filter BGP prefixes.
B. The statement "Prefixes learned from OSPF/EIGRP are never permitted inbound by default" is also true. ACI fabric, by default, blocks all incoming OSPF and EIGRP prefixes, and an import policy must be configured to permit them.
C. The prefixes that are permitted inbound are redistributed into MP-BGP at the ingress leaf. In the ACI fabric, the ingress leaf node is responsible for redistributing the external routes learned from OSPF or EIGRP into MP-BGP. The prefixes permitted inbound are redistributed into the MP-BGP domain.
D. Export route control controls whether the prefixes are redistributed from MP-BGP to the egress leaf. Export route control in the ACI fabric is used to control the prefixes that are advertised to external networks. It determines which prefixes are advertised to the egress leaf for distribution to external networks.
E. The statement "By default, import route control is always enabled while export route control is always disabled" is false. Both import and export route control are disabled by default in the ACI fabric, and they must be explicitly configured.
In summary, statements A and B are true. Statement C explains the mechanism of how incoming prefixes are redistributed into MP-BGP, and statement D explains how export route control determines the prefixes to be advertised to external networks. Finally, statement E is false as both import and export route control are disabled by default in the ACI fabric.