Cisco Cisco Packet Data Gateway (PDG) Dépliant
IPSec Network Applications
▀ Implementing IPSec for L2TP Applications
▄ Cisco StarOS IP Security (IPSec) Reference
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How IPSec is Used for L2TP Configurations on the GGSN
The following figure and the text that follows describe how IPSec-encrypted attribute-based L2TP sessions are
processed by the system.
processed by the system.
Figure 6.
GGSN PDP Context Processing with IPSec-Encrypted L2TP
Table 7. GGSN PDP Context Processing with IPSec-Encrypted L
Step
Description
1
A subscriber session/PDP Context Request arrives at the system.
2
The configuration of the APN accessed by the subscriber indicates that session data is to be tunneled using L2TP. In
addition, attributes specifying a crypto map name and ISAKMP secret are also supplied indicating that IP security is also
required.
addition, attributes specifying a crypto map name and ISAKMP secret are also supplied indicating that IP security is also
required.
3
The system determines that the crypto map name supplied matches a configured crypto map.