L2TP Disconnect Cause Information
The L2TP Disconnect Cause Information feature adds support for additional Layer 2 Tunnel Protocol (L2TP)
disconnect error codes using attribute-value (AV) pair 46 as specified by RFC 3145. Prior to the introduction
of this feature, L2TP hosts could not exchange PPP disconnect error codes.
•
Finding Feature Information, page 1
•
Restrictions for L2TP Disconnect Cause Information, page 1
•
Information About L2TP Disconnect Cause Information, page 2
•
Additional References, page 4
•
Feature Information for L2TP Disconnect Cause Information, page 5
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and
feature information, see Bug Search Tool and the release notes for your platform and software release. To
find information about the features documented in this module, and to see a list of the releases in which each
feature is supported, see the feature information table.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support.
To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Restrictions for L2TP Disconnect Cause Information
•
This feature implements only error codes that are compliant with RFC 3145.
•
If a router receives AV pair 46 with a nonsupported disconnect code it is mapped to code 0, indicating
that no information is available.
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Information About L2TP Disconnect Cause Information
How L2TP Disconnect Cause Information Works
L2TP disconnect cause codes allow the devices functioning as L2TP hosts to exchange PPP-related disconnect
cause information. Normally L2TP operation is isolated from details of the PPP session that is being
encapsulated. AV pair 46 PPP Disconnect Cause Code is used to exchange PPP-related disconnect cause
information between L2TP hosts. The information can be translated to the appropriate authentication,
authorization, and accounting (AAA) code and relayed to the remote RADIUS AAA server.
Benefits of L2TP Disconnect Cause Information
When L2TP service fails or session establishment is unsuccessful, PPP-specific disconnect information
provides valuable information that can be used for troubleshooting or accounting purposes. The lack of this
information is a problem particularly when the L2TP hosts are not owned or managed by the same entities.
The L2TP Disconnect Cause Information feature enables service providers to determine the specific failure
reason, facilitating analysis and error correction.
L2TP Disconnect Cause Information Codes
The table below lists the supported L2TP disconnect cause codes from RFC 3145 and a brief description of
the codes.
Table 1: L2TP Disconnect Cause Codes
DescriptionCode
Global Errors
No information available.
If a router receives AV pair 46 with a
nonsupported disconnect code, possibly from
another vendor or a newer version of Cisco
software, it is mapped to this code.
Note
0
Administrative disconnect.1
Normal disconnection, Link Control Protocol (LCP)
Terminate-Request sent.
Valid direction values are:
•
1--LCP Terminate-Request sent by the peer
device.
•
2--LCP Terminate-Request sent by the local
device.
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Information About L2TP Disconnect Cause Information
DescriptionCode
LCP Errors
Finite State Machine (FSM) timeout error.5
No recognizable LCP packets were received.6
LCP link failure: Echo Request timeout.8
The peer has an unexpected endpoint-discriminator
for an existing Multilink PPP (MLP) bundle.
9
Compulsory call-back required by a PPP peer was
refused by the peer.
Valid direction values are:
•
1--Required by the local device; refused by the
peer device.
•
2--Required by the peer device; refused by the
local device.
12
Authentication Errors
FSM timeout error.13
PPP authentication failed due to a bad hostname,
password, or secret.
Valid direction values are:
• 1--Authentication of the peer’s identity by the
local system failed.
•
2--Authentication of the local identity by the
peer system failed.
16
Network Control Protocol (NCP) Errors
FSM timeout error.17
No NCPs available (all disabled or rejected) or no
NCPs went to Opened state. The Control Protocol
Number can be zero only if neither peer has enabled
NCPs.
18
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L2TP Disconnect Cause Information
L2TP Disconnect Cause Information Codes
Additional References
Related Documents
Document TitleRelated Topic
Cisco IOS Master Commands List, All ReleasesCisco IOS commands
VPDN Tunnel Management moduleInformation about configuring L2TP VPDN tunnels
Cisco IOS VPDN Command Reference
VPDN commands
Standards
TitleStandard
--No new or modified standards are supported by this
feature, and support for existing standards has not
been modified by this feature.
MIBs
MIBs LinkMIB
To locate and download MIBs for selected platforms,
Cisco software releases, and feature sets, use Cisco
MIB Locator found at the following URL:
http://www.cisco.com/go/mibs
No new or modified MIBs are supported by this
feature, and support for existing MIBs has not been
modified by this feature.
RFCs
TitleRFC
L2TP Disconnect Cause InformationRFC 3145
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L2TP Disconnect Cause Information
Additional References
Technical Assistance
LinkDescription
http://www.cisco.com/cisco/web/support/index.html
The Cisco Support and Documentation website
provides online resources to download documentation,
software, and tools. Use these resources to install and
configure the software and to troubleshoot and resolve
technical issues with Cisco products and technologies.
Access to most tools on the Cisco Support and
Documentation website requires a Cisco.com user ID
and password.
Feature Information for L2TP Disconnect Cause Information
The following table provides release information about the feature or features described in this module. This
table lists only the software release that introduced support for a given feature in a given software release
train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support.
To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 2: Feature Information for the L2TP Disconnect Cause Information Feature
Feature InformationReleasesFeature Name
This feature was introduced on the
Cisco ASR 1000 Series
Aggregation Services Routers.
The L2TP Disconnect Cause
Information feature adds support
for additional Layer 2 Tunnel
Protocol (L2TP) disconnect error
codes using attribute-value (AV)
pair 46 as specified by RFC 3145.
Prior to the introduction of this
feature, L2TP hosts could not
exchange PPP disconnect error
codes.
No commands were introduced or
modified by this feature.
Cisco IOS XE Release 2.1L2TP Disconnect Cause
Information
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Feature Information for L2TP Disconnect Cause Information
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Feature Information for L2TP Disconnect Cause Information
