
206
Chapter 13 VPN
NN47922-500
The Authentication Algorithms, HMAC-MD5 (RFC 2403) and HMAC-SHA-1
(RFC 2404), provide an authentication mechanism for the
AH
and
ESP
protocols.
The
ESP
and
AH
protocols are necessary to create a Security Association (SA),
the foundation of an IPSec VPN. An SA is built from the authentication provided
by the
AH
and
ESP
protocols. The primary function of key management is to
establish and maintain the SA between systems. After the SA is established, the
transport of data can commence.
AH (Authentication Header) protocol
AH
protocol (RFC 2402) was designed for integrity, authentication, sequence
integrity (replay resistance), and nonrepudiation but not for confidentiality, for
which the
ESP
was designed.
In applications where confidentiality is not required or not sanctioned by
government encryption restrictions, an
AH
can be employed to ensure integrity.
This type of implementation does not protect the information from dissemination
but can be used for verification of the integrity of the information and
authentication of the originator.
ESP (Encapsulating Security Payload) protocol
The
ESP
protocol (RFC 2406) provides encryption, as well as the services offered
by
AH
.
ESP
authenticating properties are limited compared to the
AH
due to the
exclusion of the IP header information during the authentication process.
However,
ESP
is sufficient if only the upper layer protocols need to be
authenticated.
Summary of Contents for BSR222
Page 28: ...28 Tables NN47922 500 ...
Page 50: ...50 Chapter 2 Introducing the WebGUI NN47922 500 ...
Page 66: ...66 Chapter 3 Wizard setup NN47922 500 ...
Page 92: ...92 Chapter 5 System screens NN47922 500 ...
Page 104: ...104 Chapter 6 LAN screens NN47922 500 ...
Page 154: ...154 Chapter 9 Static Route screens NN47922 500 ...
Page 196: ...196 Chapter 11 Firewall screens NN47922 500 ...
Page 212: ...212 Chapter 13 VPN NN47922 500 Figure 68 Summary IP Policies ...
Page 256: ...256 Chapter 13 VPN NN47922 500 Figure 82 VPN Client Termination advanced ...
Page 260: ...260 Chapter 13 VPN NN47922 500 ...
Page 264: ...264 Chapter 14 Certificates NN47922 500 Figure 84 My Certificates ...
Page 290: ...290 Chapter 14 Certificates NN47922 500 Figure 95 Trusted remote host details ...
Page 314: ...314 Chapter 16 IEEE 802 1x NN47922 500 ...
Page 318: ...318 Chapter 17 Authentication server NN47922 500 Figure 107 Local User database edit ...
Page 326: ...326 Chapter 17 Authentication server NN47922 500 ...
Page 374: ...374 Chapter 20 Logs Screens NN47922 500 Figure 151 Log settings ...
Page 384: ...384 Chapter 20 Logs Screens NN47922 500 ...
Page 402: ...402 Chapter 22 Maintenance NN47922 500 Figure 170 Restart screen ...