Netopia 3300-ENT - page 127

Internet Key Exchange (IKE) IPsec Key Management for VPNs 5-1
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IPsec stands for IP Security, a set of protocols that supports secure exchange of IP packets at the IP layer.
IPsec is deployed widely to implement Virtual Private Networks (VPNs). See “Virtual Private Networks (VPNs)”
on page 4-1 for more information.
The Netopia Firmware Version 8.4 supports Internet Key Exchange (IKE) for secure encrypted communication
over a VPN tunnel.
This chapter covers the following topics:
•“Overview” on page 5-1
•“Internet Key Exchange (IKE) Configuration” on page 5-2
•“Key Management” on page 5-8
•“IPsec WAN Configuration Screens” on page 5-18
•“IPsec Manual Key Entry” on page 5-19
Overview
IPsec supports two encapsulation modes: Transport and Tunnel. Transport mode encrypts only the data por tion
(payload) of each packet, but leaves the header untouched. Tunnel mode encrypts both the header and the
payload. On the receiving side, an IPsec-compliant device decrypts each packet. Netopia Routers support
Tunnel mode.
DES stands for Data Encryption Standard, a popular symmetric-key encryption method. DES uses a 56-bit key.
Netopia Routers offer IPsec 3DES (triple DES) encryption as a standard option.
Internet Key Exchange (IKE) is an authentication and encryption key management protocol used in conjunction
with the IPsec standard.
IKE is a two-phase protocol for key exchange.
•Phase 1 authenticates the security gateways and establishes the Security Parameters (SPs) they will use
to negotiate on behalf of the clients. Security Associations (SAs) are sets of information values that allow
the two devices on the Internet to communicate securely.
•Phase 2 establishes the tunnel and provides for secure transport of data.
IPsec can be configured without IKE, but IKE offers additional features, flexibility, and ease of configuration. Key
exchange between your local Router and a remote point can be configured either manually or by using the key
exchange protocol.