Configuring AVP Attributes of L2TP Packets

The control messages used to connect tunnels contain multiple AVP attributes. You can configure the AVP attributes of packets to adjust L2TP connections.

Context

Different AVP attributes contain different information. You can configure the AVP attributes of L2TP packets to store the AVP information, thereby controlling the transmission of packets. Perform the following operations on the NetEngine 8000 F:

Procedure

Encapsulate the AVP 22 attribute into L2TP packets.
In a scenario where the NetEngine 8000 F functions as a LAC and an L2TP user attempts to go online, you can run the l2tp calling-number-avp enable command to determine whether to encapsulate the AVP 22 attribute into ICRQ packets to be sent by the LAC.
1. Run system-view
  The system view is displayed.
2. Run l2tp calling-number-avp enable
  The AVP 22 attribute is added to L2TP packets.
3. Run l2tp-group group-name
  The L2TP group view is displayed.
4. (Optional) Run any of the following commands to configure the LAC to encapsulate the AVP 22 attribute in ICRQ packets to be sent in the new format:
  - To configure the LAC to encapsulate the AVP 22 attribute into ICRQ packets to be sent in the version1 format, run the calling-number-avp format version1 [ delimiter delimiter ] { option82 [ delimiter delimiter ] | mac [ delimiter delimiter ] | interface [ delimiter delimiter ] | domain [ delimiter delimiter ] | sysname [ delimiter delimiter ] | vlan [ delimiter delimiter ] | pevlan [ delimiter delimiter ] | cevlan [ delimiter delimiter ]| agent-circuit-id [ delimiter delimiter ] | agent-remote-id [ delimiter delimiter ] }^* } or calling-number-avp format version1 include option82 command.
  - To configure the LAC to encapsulate the AVP 22 attribute into ICRQ packets to be sent in a user-defined format, run the calling-number-avp format include [ delimiter delimiter ] { option82 [ delimiter delimiter ] | mac [ delimiter delimiter ] | interface [ delimiter delimiter ] | domain [ delimiter delimiter ] | sysname [ delimiter delimiter ] | vlan [ delimiter delimiter ] | pevlan [ delimiter delimiter ] | cevlan [ delimiter delimiter ]| agent-circuit-id [ delimiter delimiter ] | agent-remote-id [ delimiter delimiter ] }^* } command.
  - (Optional) To configure the LAC to encapsulate the AVP 22 attribute into ICRQ packets to be sent in the version3 format, run the calling-number-avp format version3 command.
5. (Optional) Run calling-number-avp format llid
  The AVP 22 attribute is used to carry the LLID to the LNS.
6. (Optional) Set the offset of the inner VLAN ID encapsulated into ICRQ packets.
  1. Run interface interface-type interface-number
    
    The interface view is displayed.
  2. Run bas
    
    The BAS interface view is displayed.
  3. Run calling-number-avp cevlan-offset offset-value
    
    The offset of the inner VLAN ID encapsulated into ICRQ packets is set.
  If packets sent from different DSLAMs have the same CE-VLAN ID and the CE-VLAN ID must be identified in the ICRQ packets to be sent by the LAC, configure an offset for the CE-VLAN ID.
  
  The offset configuration can take effect only when the CVE-VLAN ID has been encapsulated into the AVP 22 attribute of ICRQ packets using the calling-number-avp format include cevlan [ delimiter delimiter ] command.
7. (Optional) Run avp calling-number interface-format exclude sub-slot
  The interface description of the AVP 22 attribute carried in L2TP packets does not contain the subslot ID.
8. Run commit
  The configuration is committed.
Hide AVPs in transmission.
The L2TP protocol uses AVPs to send and negotiate L2TP attributes. For security purposes, you can hide AVPs in transmission.
1. Run system-view
  The system view is displayed.
2. Run l2tp-group group-name
  The L2TP group view is displayed.
3. Run tunnel avp-hidden
  AVPs are hidden in transmission.
  
  The function to hide AVPs in transmission takes effect only when tunnel authentication is enabled on both ends of a tunnel.
  
  After AVPs are hidden in transmission, if AAA authentication is used for a tunnel, the two ends must use the same password.
4. Run commit
  The configuration is committed.
Enable AVP 46 for a tunnel.
After AVP 46 is enabled for a tunnel, the cause of tunnel teardown is added to the STOPCCN packets sent from the LAC to the LNS.
1. Run system-view
  The system view is displayed.
2. Run l2tp-group group-name
  The L2TP group view is displayed.
3. Run tunnel avp46
  AVP 46 is enabled for the tunnel.
4. Run commit
  The configuration is committed.
Configure the AVP 47 attribute of L2TP packets.
After the AVP 47 attribute is configured, the LAC marks the outer DSCP value of the L2TP packets so that the packets with different DSCP values have different priorities.
1. Run system-view
  The system view is displayed.
2. Run l2tp-group group-name
  The L2TP group view is displayed.
3. Run set-dscp-outer dscp
  The outer DSCP value of L2TP packets is configured so that the LAC can negotiate with the peer device (LNS) for the AVP 47 attribute.
4. Run commit
  The configuration is committed.