remote device, which will decrypt/authenticate the data,
extract it from its tunnel and pass it on to its final destination.
This way, an eavesdropper will only see encrypted traffic
going from one of VPN endpoint to another.
In transport mode, the traffic will not be tunneled, and is
hence not applicable to VPN tunnels. It can be used to secure
a connection from a VPN client directly to the NetDefend
Firewall,
for
example
for
IPsec
protected
remote
configuration.
This setting will typically be set to "tunnel" in most
configurations.
Remote Endpoint
The remote endpoint (sometimes also referred to as the
remote
gateway)
is
the
device
that
does
the
VPN
decryption/authentication and that passes the unencrypted
data on to its final destination. This field can also be set to
None, forcing the NetDefend Firewall to treat the remote
address as the remote endpoint. This is particularly useful in
cases of roaming access, where the IP addresses of the remote
VPN clients are not known beforehand. Setting this to "none"
will allow anyone coming from an IP address conforming to
the "remote network" address discussed above to open a VPN
connection, provided they can authenticate properly.
The remote endpoint can be specified as a URL string such as
vpn.company.com. If this is done, the prefix dns: must be
used. The string above should therefore be specified as
dns:vpn.company.com.
The remote endpoint is not used in transport mode.
Main/Aggressive Mode
The IKE negotiation has two modes of operation, main mode
and aggressive mode.
The difference between these two is that aggressive mode will
pass more information in fewer packets, with the benefit of
slightly faster connection establishment, at the cost of
transmitting the identities of the security firewalls in the clear.
When using aggressive mode, some configuration parameters,
such as Diffie-Hellman groups and PFS, cannot be negotiated
and this mean it is important to have "compatible"
configurations at both ends.
IPsec Protocols
The IPsec protocols describe how the data will be processed.
The two protocols to choose from are AH, Authentication
Header, and ESP, Encapsulating Security Payload.
ESP provides encryption, authentication, or both. However, it
is not recommended to use encryption only, since it will
dramatically decrease security.
Note that AH only provides authentication. The difference
from ESP with authentication only is that AH also
authenticates parts of the outer IP header, for instance source
and destination addresses, making certain that the packet
really came from who the IP header claims it is from.
9.3.2. Internet Key Exchange (IKE)
Chapter 9. VPN
400
Summary of Contents for NetDefend DFL-260E
Page 27: ...1 3 NetDefendOS State Engine Packet Flow Chapter 1 NetDefendOS Overview 27...
Page 79: ...2 7 3 Restore to Factory Defaults Chapter 2 Management and Maintenance 79...
Page 146: ...3 9 DNS Chapter 3 Fundamentals 146...
Page 227: ...4 7 5 Advanced Settings for Transparent Mode Chapter 4 Routing 227...
Page 241: ...5 4 IP Pools Chapter 5 DHCP Services 241...
Page 339: ...6 7 Blacklisting Hosts and Networks Chapter 6 Security Mechanisms 339...
Page 360: ...7 4 7 SAT and FwdFast Rules Chapter 7 Address Translation 360...
Page 382: ...8 3 Customizing HTML Pages Chapter 8 User Authentication 382...
Page 386: ...The TLS ALG 9 1 5 The TLS Alternative for VPN Chapter 9 VPN 386...
Page 439: ...Figure 9 3 PPTP Client Usage 9 5 4 PPTP L2TP Clients Chapter 9 VPN 439...
Page 450: ...9 7 6 Specific Symptoms Chapter 9 VPN 450...
Page 488: ...10 4 6 Setting Up SLB_SAT Rules Chapter 10 Traffic Management 488...
Page 503: ...11 6 HA Advanced Settings Chapter 11 High Availability 503...
Page 510: ...12 3 5 Limitations Chapter 12 ZoneDefense 510...
Page 533: ...13 9 Miscellaneous Settings Chapter 13 Advanced Settings 533...
