Hub-and-Spoke Network SAF Advertisements

E.

In this scenario, the collaboration engineer has implemented SAF as a hub-and-spoke network, where the hub router uses its loopback interface for SAF advertisements. However, the issue is that updates are coming into the hub router but are not being advertised out. Let's review each of the options and see which one describes the issue:

A. Multicast is not enabled across the WAN: This option is unlikely to be the issue as multicast is required for SAF, and if it were not enabled, updates would not be coming into the hub router.

B. SAF is set up on a VR: This option is also unlikely to be the issue as SAF can be set up on a virtual router (VR), and this configuration should not impact the advertisements from the hub router.

C. SAF username/password are incorrect: This option is not relevant to the issue as SAF does not require a username or password for operation.

D. The autonomous system is mismatched: This option is a possibility as SAF requires a matching autonomous system (AS) number across all routers in the network. If the hub router's AS number does not match the AS numbers of the other routers, then updates may be received but not advertised out.

E. Split horizon is enabled: This option is a possibility as split horizon is a feature that can prevent updates from being advertised back out of the interface they were received on. If split horizon is enabled on the hub router, it could prevent updates from being advertised out to the spoke routers.

Therefore, the issue is most likely either a mismatched autonomous system number or enabled split horizon. The collaboration engineer should verify the configuration and disable split horizon if necessary to allow updates to be advertised out to the spoke routers.