Nortel 1010 用户指南

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页码 178
76 Chapter 4 Configuring user tunnels
NN46110-500 
 
The Nortel VPN Router associates all remote users with a group, which dictates 
the attributes that are assigned to a remote user session. A group can even consist 
of a single user, thereby creating a personal connection. 
The Nortel VPN Router organizes groups in a hierarchical manner. At the top of 
the hierarchy is the base group. The base group \Base contains the default 
characteristics that each new group inherits. You add additional groups to the 
hierarchy as children of the base group. 
The Nortel VPN Router takes precautions against unauthorized users potentially 
hacking tunneled information when the Nortel VPN Router is operating in split 
tunnel mode. The primary precaution is to drop packets that do not have the IP 
address that is assigned to the tunnel connection as its source address. For 
example, you establish a PPP dial-up connection to the Internet with an IP address 
of 192.168.21.3. When you start the tunneled connection to a Nortel VPN Router, 
you are assigned a tunnel IP address of 192.192.192.192. Now, any packets that 
attempt to pass through the tunnel connection with a source IP address of 
192.168.21.3 (or any address other than 192.192.192.192) are dropped. 
Furthermore, you can enable filters on the Nortel VPN Router to limit the protocol 
types that can pass through a tunneled connection.
Password aging does not work for administrator accounts. Also, the following are 
client-specific password management symptoms: 
If you are using the IPsec client, you are warned three times that there will be 
an impending password expiration. You should change the password 
immediately. IPsec clients using versions earlier than 1.5.2 do not receive a 
password expiration warning. 
If you are using the PPTP client with the Connection Manager, the 
Connection Manager generates an impending password expiration warning. 
Other clients (L2TP and L2F) and PPTP client users who are not using the 
Connection Manager have no warning and no longer can log on. You must 
contact your system administrator if this happens. In this case, the Nortel 
VPN Router is unable to notify the client because it has no actual control over 
the client. With PPTP, use the Connection Manager to establish a connection. 
With L2TP or L2F, set the Password Maximum Age to zero (never expires).
Note: PPP multilink is not supported with branch office tunnels. It is 
only supported with end user tunnels.