RUGGEDCOM ROX II
CLI User Guide
Chapter 12
Tunneling and VPNs
IPsec Modes
405
based on the Diffie-Hellman key exchange protocol, which allows two parties without any initial shared secret to
create one in a manner immune to eavesdropping.
CONTENTS
•
Section 12.8.1.1, “IPsec Modes”
•
Section 12.8.1.2, “Supported Encryption Protocols”
•
Section 12.8.1.3, “Public and Secret Key Cryptography”
•
Section 12.8.1.4, “X509 Certificates”
•
Section 12.8.1.5, “NAT Traversal”
•
Section 12.8.1.6, “Remote IPsec Client Support”
•
Section 12.8.1.7, “IPsec and Router Interfaces”
Section 12.8.1.1
IPsec Modes
IPsec has two basic modes of operation. In
transport
mode, IPsec headers are added as the original IP datagram
is created. The resultant packet is composed of an IP header, IPsec headers and IP payload (including a transport
header). Transport mode is most commonly used between IPsec end-stations, or between an end-station and a
gateway.
In
tunnel
mode, the original IP datagram is created normally and then encapsulated into a new IP datagram. The
resultant packet is composed of a new IP header, IPsec headers, old IP header and IP payload. Tunnel mode is most
commonly used between gateways, the gateway acting as a proxy for the hosts behind it.
Section 12.8.1.2
Supported Encryption Protocols
Libreswan supports the following standard encryption protocols:
•
3DES (Triple DES)
Uses three Data Encryption Standard (DES) encryptions on a single data block, with at least two different keys,
to get higher security than is available from a single DES pass. 3DES is the most CPU intensive cipher.
•
AES
The Advanced Encryption Standard (AES) protocol cipher uses a 128-bit block and 128, 192 or 256-bit keys. This
is the most secure protocol in use today, and is much preferred to 3DES due to its efficiency.
Section 12.8.1.3
Public and Secret Key Cryptography
In
public key
cryptography, keys are created in matched pairs (called public and private keys). The public key is
made public while the private key is kept secret. Messages can then be sent by anyone who knows the public key
to the holder of the private key. Only the owner of the private key can decrypt the message.
When this form of encryption is used, each router configures its VPN connection to use the RSA algorithm and
includes the public signature of its peer.
Содержание RUGGEDCOM ROX II
Страница 2: ...RUGGEDCOM ROX II CLI User Guide ii ...
Страница 4: ...RUGGEDCOM ROX II CLI User Guide iv ...
Страница 39: ...RUGGEDCOM ROX II CLI User Guide Table of Contents xxxix 19 5 VLANs 752 ...
Страница 40: ...Table of Contents RUGGEDCOM ROX II CLI User Guide xl ...
Страница 46: ...Preface RUGGEDCOM ROX II CLI User Guide xlvi Customer Support ...
Страница 96: ...Chapter 2 Using RUGGEDCOM ROX II RUGGEDCOM ROX II CLI User Guide 50 Accessing Maintenance Mode ...
Страница 170: ...Chapter 5 System Administration RUGGEDCOM ROX II CLI User Guide 124 Deleting a Scheduled Job ...
Страница 256: ...Chapter 6 Security RUGGEDCOM ROX II CLI User Guide 210 Enabling Disabling a Firewall ...
Страница 402: ...Chapter 11 Wireless RUGGEDCOM ROX II CLI User Guide 356 Managing Cellular Modem Profiles ...
Страница 646: ...Chapter 13 Unicast and Multicast Routing RUGGEDCOM ROX II CLI User Guide 600 Deleting a Multicast Group Prefix ...
Страница 732: ...Chapter 15 Network Discovery and Management RUGGEDCOM ROX II CLI User Guide 686 Viewing NETCONF Statistics ...
Страница 790: ...Chapter 17 Time Services RUGGEDCOM ROX II CLI User Guide 744 Deleting a Broadcast Multicast Address ...