Chapter 19 VPN
VMG1312-B10C User’s Guide
216
The Encryption Algorithm describes the use of encryption techniques such as DES (Data Encryption
Standard) and Triple DES algorithms.
The Authentication Algorithms, HMAC-MD5 (RFC 2403) and HMAC-SHA-1 (RFC 2404, provide an
authentication mechanism for the
AH
and
ESP
protocols.
Key Management
Key management allows you to determine whether to use IKE (ISAKMP) or manual key
configuration in order to set up a VPN.
19.3.2 Encapsulation
The two modes of operation for IPSec VPNs are
Transport
mode and
Tunnel
mode. At the time of
writing, the Device supports
Tunnel
mode only.
Figure 123
Transport and Tunnel Mode IPSec Encapsulation
Transport Mode
Transport
mode is used to protect upper layer protocols and only affects the data in the IP packet.
In
Transport
mode, the IP packet contains the security protocol (
AH
or
ESP
) located after the
original IP header and options, but before any upper layer protocols contained in the packet (such
as TCP and UDP).
With
ESP,
protection is applied only to the upper layer protocols contained in the packet. The IP
header information and options are not used in the authentication process. Therefore, the
originating IP address cannot be verified for integrity against the data.
With the use of
AH
as the security protocol, protection is extended forward into the IP header to
verify the integrity of the entire packet by use of portions of the original IP header in the hashing
process.
Tunnel Mode
Tunnel
mode encapsulates the entire IP packet to transmit it securely. A
Tunnel
mode is required
for gateway services to provide access to internal systems.
Tunnel
mode is fundamentally an IP
tunnel with authentication and encryption. This is the most common mode of operation.
Tunnel
mode is required for gateway to gateway and host to gateway communications.
Tunnel
mode
communications have two sets of IP headers:
•
Outside header
: The outside IP header contains the destination IP address of the VPN gateway.
Содержание VMG1312-B10C
Страница 4: ...Contents Overview VMG1312 B10C User s Guide 4 Diagnostic 265 Troubleshooting 271 ...
Страница 14: ...Table of Contents VMG1312 B10C User s Guide 14 ...
Страница 15: ...15 PART I User s Guide ...
Страница 16: ...16 ...
Страница 22: ...Chapter 1 Introducing the Device VMG1312 B10C User s Guide 22 ...
Страница 33: ...33 PART II Technical Reference ...
Страница 34: ...34 ...
Страница 64: ...Chapter 5 Broadband VMG1312 B10C User s Guide 64 ...
Страница 100: ...Chapter 6 Wireless VMG1312 B10C User s Guide 100 ...
Страница 124: ...Chapter 7 Home Networking VMG1312 B10C User s Guide 124 ...
Страница 166: ...Chapter 10 Network Address Translation NAT VMG1312 B10C User s Guide 166 ...
Страница 176: ...Chapter 12 Interface Group VMG1312 B10C User s Guide 176 ...
Страница 192: ...Chapter 14 Firewall VMG1312 B10C User s Guide 192 ...
Страница 198: ...Chapter 16 Parental Control VMG1312 B10C User s Guide 198 ...
Страница 208: ...Chapter 18 Certificates VMG1312 B10C User s Guide 208 ...
Страница 211: ...Chapter 19 VPN VMG1312 B10C User s Guide 211 Figure 121 IPSec VPN Add ...
Страница 224: ...Chapter 20 Log VMG1312 B10C User s Guide 224 ...
Страница 234: ...Chapter 24 IGMP Status VMG1312 B10C User s Guide 234 ...
Страница 238: ...Chapter 25 xDSL Statistics VMG1312 B10C User s Guide 238 ...
Страница 242: ...Chapter 27 User Account VMG1312 B10C User s Guide 242 ...
Страница 248: ...Chapter 30 TR 064 VMG1312 B10C User s Guide 248 ...
Страница 252: ...Chapter 31 Time Settings VMG1312 B10C User s Guide 252 ...
Страница 264: ...Chapter 35 Configuration VMG1312 B10C User s Guide 264 ...
Страница 270: ...Chapter 36 Diagnostic VMG1312 B10C User s Guide 270 ...
Страница 288: ...Appendix B Legal Information VMG1312 B10C User s Guide 288 ...