Cisco Cisco ISA550 Integrated Security Appliance Anleitung Für Quick Setup

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Network Extension Mode (NEM) determines whether the inside hosts relative to the Cisco VPN hardware 
client (ISA500) are accessible from the corporate network over the VPN tunnel. In NEM mode, the Cisco 
VPN hardware client obtains a private IP address from a local DHCP server or is configured with a static 
IP address.

 illustrates how NEM mode works. In this example, the ISA500 acts as a Cisco VPN hardware 

client and is connected to a remote IPsec VPN server. The hosts attached to the ISA500 have IP 
addresses in the 10.0.0.0 private network space. The VPN server does not assign an IP address to the 
ISA500 (which does not perform NAT or PAT translation over the VPN tunnel). When accessing the 
remote network (192.168.100.x), the hosts (10.0.0.3) and (10.0.04) are not translated, but the hosts in 
the remote network (192.168.100.x) can access the hosts (10.0.0.3 and 10.0.04) directly.

The client hosts are assigned IP addresses that are fully routable by the destination network over the 
VPN tunnel. These IP addresses could be either in the same subnet space as the destination network or 
in separate subnets, assuming that the destination routers are configured to properly route those IP 
addresses over the VPN tunnel. For information about how to configure the ISA500 in NEM mode, see 

.

IPsec VPN Network Extension Connection