You are configuring an L3Out interface for a VRF for which OSPF is configured on an ACI fabric.
You notice that the OSPF routing table is rebuilt every 10 seconds.
Which reason for this behavior is true?
Click on the arrows to vote for the correct answer
A. B. C. D.Explanation.
The answer to this question is D. This is the normal behavior of the ACI fabric.
When an L3Out interface is configured for a VRF on an ACI fabric, OSPF is used as the routing protocol to exchange routing information between the ACI fabric and the external network. The OSPF process in the ACI fabric maintains a routing table, also known as the RIB (Routing Information Base), which contains the learned routes and their associated metrics.
By default, the OSPF process in the ACI fabric rebuilds the RIB every 10 seconds. This behavior is normal and is not indicative of any issue or misconfiguration. However, if the RIB is being rebuilt too frequently, it can result in increased CPU and memory usage on the ACI fabric, which can impact its performance.
It is important to note that OSPF timers can be configured in the ACI fabric to control the frequency of the RIB rebuild process. However, this is not the reason for the behavior observed in the question.
Option A, a duplex mismatch on the L3Out interface, can cause issues with connectivity and can impact OSPF routing, but it is not the reason for the frequent RIB rebuilds.
Option B, configuring loopback interfaces with an IP address that is already in use can cause IP address conflicts, but it does not impact OSPF routing or the RIB rebuild process.
In summary, the frequent rebuilding of the OSPF RIB every 10 seconds is normal behavior in an ACI fabric and not indicative of any issue or misconfiguration.