Cisco Cisco IOS Software Release 12.3(11)T

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The L2TP—IPSec Support for NAT and PAT Windows Clients feature allows more than one Windows 
client to connect to a Layer 2 Tunneling Protocol (L2TP) Network Server (LNS) at one time with IP 
Security (IPSec) enabled and a network address translation (NAT) or port address translation (PAT) 
server between the Windows client and LNS.

Currently, if one Windows client is connected to a Cisco IOS LNS router through a NAT or PAT server 
with IPSec enabled, and then another Windows client connects to the same Cisco IOS LNS router, the 
first client’s connection is effectively terminated. Enabling L2TP—IPSec Support for NAT and PAT 
Windows Clients ensures that Windows client connections in this environment are established and 
maintained until the connection is closed.

Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image 
support. Access Cisco Feature Navigator at 

. You must have an account on 

Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at 
the login dialog box and follow the instructions that appear. 

12.3(11)T4

This feature was introduced.

12.4(1)

This feature was integrated into Release 12.4(1).