What are the two reasons a customer chooses to use IPsec tunnels over GRE? (Choose two.)

While IPsec can utilize keepalives, its failure detection isn't inherently faster than GRE, which can also be combined with protocols like BFD for rapid failure detection.

GRE tunnels generally have lower overhead than IPsec due to fewer security operations, potentially offering slightly higher bandwidth efficiency in some scenarios, rather than IPsec providing higher bandwidth.

vFlowd is a Cisco proprietary flow monitoring daemon, not a general requirement or distinguishing factor between IPsec and GRE tunnel choices.

IPsec natively supports NAT traversal (NAT-T), allowing IPsec tunnels to be established even when one or both endpoints are behind a NAT device, which is a common scenario in enterprise networks.

IPsec provides robust security features, including data confidentiality (encryption), data integrity, and authentication, making it a more secure choice for protecting data in transit compared to GRE, which primarily encapsulates packets without inherent security.