Dell S4048T, Configuration Manual

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Internet Protocol Security (IPSec)
Internet protocol security (IPSec) is an end-to-end security scheme for protecting IP communications by
authenticating and encrypting all packets in a communication session. Use IPSec between hosts, between
gateways, or between hosts and gateways.
IPSec is compatible with Telnet and FTP protocols. It supports two operational modes: Transport and Tunnel.
• Transport mode — (default) Use to encrypt only the payload of the packet. Routing information is
unchanged.
• Tunnel mode — Use to encrypt the entire packet including the routing information of the IP header.
Typically used when creating virtual private networks (VPNs).
NOTE: Due to performance limitations on the control processor, you cannot enable IPSec on all packets
in a communication session.
IPSec uses the following protocols:
• Authentication Headers (AH) — Disconnected integrity and origin authentication for IP packets
• Encapsulating Security Payload (ESP) — Confidentiality, authentication, and data integrity for IP packets
• Security Associations (SA) — Necessary algorithmic parameters for AH and ESP functionality
IPSec supports the following authentication and encryption algorithms:
• Authentication only:
• MD5
• SHA1
• Encryption only:
• 3DES
• CBC
• DES
• ESP Authentication and Encryption:
• MD5 & 3DES
• MD5 & CBC
• MD5 & DES
• SHA1 & 3DES
• SHA1 & CBC
• SHA1 & DES
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