olemus
virtuaalne privaatvõrk, mis põhineb protokolli IPsec tunnelirežiimil
= a VPN that is based on the tunnel mode of the IPSec protocol

ülevaateid
https://www.freebsd.org/doc/en/books/handbook/ipsec.html

http://www.eetimes.com/document.asp?doc_id=1275828

https://www.ietf.org/proceedings/49/slides/ppvpn-2.pdf

http://www.infosecwriters.com/text_resources/pdf/Demystifying_IPSec_VPNs.pdf

https://cdn.ttgtmedia.com/rms/pdf/Basic_IPsec_VPN_topologies_and_configurations.pdf

https://www.oracle.com/a/ocom/docs/ipsec-vpn-best-practices.pdf

https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-77r1.pdf