L2TP Access Concentrator
Modifying PDSN Services for L2TP Support ▀
Cisco ASR 5x00 Packet Data Network Gateway Administration Guide ▄
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Modifying PDSN Services for L2TP Support
PDSN service modification is required for compulsory tunneling and optional for attribute-based tunneling.
For attribute-based tunneling, a configuration error could occur such that upon successful authentication, the system
determines that the subscriber session requires L2TP but can not determine the name of the context in which the
appropriate LAC service is configured from the attributes supplied. As a precautionary, a parameter has been added to
the PDSN service configuration options that will dictate the name of the context to use. It is strongly recommended that
this parameter be configured.
This section contains instructions for modifying the PDSN service configuration for either compulsory or attribute-
based tunneling.
Important:
This section provides the minimum instruction set for modifying PDSN service for L2TP support on
the system. For more information on commands that configure additional parameters and options, refer to the
LAC
Service Configuration Mode Commands
chapter in the
Command Line Interface Reference
.
To configure the LAC services on system:
Step 1
Modify the PDSN service to support L2TP by associating LAC context and defining tunnel type by applying the
example configuration in the
Modifying PDSN Service
section.
Step 2
Verify your configuration to modify PDSN service by following the steps in the
Verifying the PDSN Service for L2TP
Support
section.
Step 3
Save your configuration to flash memory, an external memory device, and/or a network location using the Exec mode
command
save configuration
. For additional information on how to verify and save configuration files, refer to the
System Administration Guide
and the
Command Line Interface Reference
.
Modifying PDSN Service
Use the following example to modify the PDSN service to support L2TP by associating LAC context and defining
tunnel type:
configure
context <source
_ctxt_name
> [ -noconfirm ]
pdsn-service <
pdsn_service_name
>
ppp tunnel-context <
lac_context_name
>
ppp tunnel-type { l2tp | none }
end
Notes:
<
source_ctxt_name
> is the name of the source context containing the PDSN service, which you want to
modify for L2TP support.