Nortel Networks 608(WL) Manuale Utente

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Chapter 4
Configuration via the Command Line Interface
E-DOC-CTC-20051017-0169 v0.1
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Physical Interface [phyif]
You can tie the peer to one of your SpeedTouch™ interfaces. This interface is then 
used as the primary carrier for your VPN connection. In general, the primary 
untrusted interface is your DSL connection to the public Internet. On the DSL line, 
various logical connections can be defined, eventually using different protocol 
stacks (IpoA, PPPoE, PPPoA,…). The peer entity has to be tied to the correct IP 
connection.
In the SpeedTouch™ the routing engine determines which interface is used for the 
VPN connection (your DSL connection to the Internet in most cases). So, what is the 
relevance to select a physical interface? 
First of all, for incoming VPN connections where your SpeedTouch™ is the 
responder in the IKE negotiations, the interface is part of the matching process for 
accepting the connection. Selecting the default value any has the effect of removing 
this matching criterion. If you select a specific interface as Primary Untrusted 
Physical Interface
, then a 
new
 incoming VPN connection on a 
backup
 
interface
 is 
not accepted.
Secondly, if your SpeedTouch™ is equipped with a backup physical interface, for 
example an ISDN backup interface, then this field determines the 
preferred
 
interface for your VPN connection. This interface is used whenever it is available. 
When this interface fails, the active VPN connections are re-routed via the backup 
interface. When the primary interface becomes available again, the VPN 
connections are re-routed to the primary interface. On the other hand, when you 
select any as the Primary Untrusted Physical Interface and this interface fails, the 
active VPN connections are also re-routed to the backup interface. But when the 
DSL connection becomes available again, the VPN connections are not re-routed as 
long as the backup connection is available. 
Peer descriptor [descr]
This parameter refers to the symbolic name of the Peer Security Descriptor to be 
used for the IKE negotiation. Pre-defined as well as user-defined peer descriptors 
can be referred to. 
Authentication Attribute
[auth]
This parameter refers to the symbolic name of the applicable Authentication 
Attribute. Either pre-shared key or certificates can be used for authentication. For 
pre-shared key authentication, the pre-shared key value is part of this parameter. In 
this document only pre-shared key authentication is considered.
client/server
This optional parameter refers to a dialup VPN client/server descriptor. Client/server 
connections are handled in chapter 
 as an advanced configuration.
options
This parameter refers to the symbolic name of an option list. This option list 
contains a number of options that modify the VPN behaviour. The options are 
handled in chapter 
discussing the advanced features. For a basic IPSec 
configuration, no option list is selected.
The IPSec peer can also be tied to the LAN interface (eth0). This could be 
useful to set up a secure connection with a local host within the local LAN 
for testing purposes, or when a redundant gateway to the public Internet, 
other than the SpeedTouch™, is present in the LAN.