If you experience problems receiving L2TP
data, use the following process to debug the problem.
Important: L2TP traffic must be routed to the
L2TP server. Refer to Data connection details and Global port matrix for more information.
- Configure logging to capture any
failure to receive traffic. In
/opt/arris/conf/l2tp-receiver-logging.properties set the
following parameters:
- Set logger_pw_session_manager to a level of
WARNING, and set the handler to
main_file_handler. The entry should appear as:
[logger_pw_session_manager] qualname=com.arris.pw.pw_session_manager level=WARNING handlers=main_file_handler - Set
main_file_handler to a logging level of WARNING. The
entry should appear as:
[handler_main_file_handler] class=logging.handlers.RotatingFileHandler formatter=formatter level=WARNING # rotate once file reaches 100M with 5 backups args=(os.path.join('logs','l2tp-receiver.log'), 'a', 100000000, 5NOTE: You can use a lower log level (INFO or DEBUG, for example), but the volume of messages you receive may prevent you from recognizing the traffic failure message.
- Set logger_pw_session_manager to a level of
WARNING, and set the handler to
main_file_handler. The entry should appear as:
- Set up a spectrum capture from the ServAssure NXT UI.
- Watch the log file /opt/arris/logs/l2tp-receiver.log.
If you configured the listening session and no data is received from the RMD or RPD, the following message is shown after about 30 seconds: 2023-10-31 16:09:30,269 WARNING [com.arris.pw.pw_session_manager] [MainThread] - L2TP idle timer for mock_tx-4 has expired.
If the above message is shown, then the ServAssure L2TP Receiver is listening for data but is not receiving data.
- Use tcpdump to check if the expected data is flowing.
- Specify the interface on which the ServAssure L2TP Receiver is listening.
- Specify the address of the RPD or RMD.
- If data is flowing datagrams are returned, similar to:
[arris@devp5poller2 ~]$ sudo tcpdump -i ens192 host 2620:107:9080:cffe::204:4 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on ens192, link-type EN10MB (Ethernet), capture size 262144 bytes 12:38:54.521228 IP6 2620:107:9080:cffe::204:4 > devp5poller2: ip-proto-115 1298 12:38:54.521414 IP6 2620:107:9080:cffe::204:4 > devp5poller2: ip-proto-115 1298 12:38:54.521476 IP6 2620:107:9080:cffe::204:4 > devp5poller2: ip-proto-115 1298 12:38:54.521538 IP6 2620:107:9080:cffe::204:4 > devp5poller2: ip-proto-115 1298 12:38:54.521651 IP6 2620:107:9080:cffe::204:4 > devp5poller2: ip-proto-115 1298