Heather has been tasked with setting up and implementing VPN tunnels to remote offices.

IPsec VPN tunnels operate at the network layer of the OSI model. This is because IPsec is designed to secure IP communications by authenticating and encrypting each IP packet of a communication session. IPsec includes protocols for establishing mutual authentication between agents at the beginning of a session and negotiation of cryptographic keys to be used during the session. IPsec can protect data flows between a pair of hosts (host-to-host), between a pair of security gateways (network-to-network), or between a security gateway and a host (network-to-host). By functioning at the network layer, IPsec VPNs are able to secure all traffic that passes through them, not just specific applications or sessions.

References: The information provided is based on standard networking protocols and the OSI model as covered in the EC-Council’s Certified Network Defender (CND) program, which includes a comprehensive understanding of network security measures like IPsec123.