IPsec is a suite of protocols used to secure connections over the internet. It provides a network-layer security architecture that applies its security protections to each IP packet, securing them with data source authentication, integrity verification, confidentiality protection, and more. The three main protocols comprising IPsec are Authentication Header (AH), Encapsulating Security Payload (ESP), and Internet Key Exchange (IKE). IPsec VPNs are commonly used for remote access and site-to-site connections due to their high level of protection. However, it has some drawbacks related to its complexity, which can lead to incorrect implementation or configuration, resulting in unintended security consequences. Despite this, IPsec is a mature protocol suite that supports a range of encryption and hashing algorithms and is highly scalable and interoperable.