A network designer wants to improve a company network design due to multiple network crashes. Which technology would allow for the restore of a network connection without informing the Layer 3…

BFD actively detects forwarding plane failures and then notifies Layer 3 routing protocols to trigger reconvergence - it informs Layer 3 of the failure rather than hiding it.

APS is a Layer 1/2 mechanism used in SONET/SDH and similar technologies that detects physical-layer failures and automatically switches traffic to a pre-provisioned protection circuit, typically within 50ms. Because the switchover occurs entirely below the Layer 3 plane, routing protocols such as OSPF or BGP do not detect the failure and do not reconverge - the connection is restored without the Layer 3 protocol ever being informed.

UDLD detects unidirectional Ethernet link failures and disables the affected port, but it does not restore connectivity or switch to an alternate path transparently.

Ethernet OAM (IEEE 802.3ah/802.1ag) provides link monitoring and fault notification but does not perform automatic protection switching or restore connectivity in a way that is transparent to Layer 3.