Description

Internal session termination codes can be very helpful for troubleshooting subscriber-related issues on MX routers that are serving as a broadband gateway, and for monitoring its health state. In order to use this data effectively, it is important to understand which internal termination code corresponds to which real life scenario.

This article provides an overview of some most common scenarios for PPPoE subscriber sessions.

Solution

For an explanation of the termination codes for PPPoE subscriber sessions, see Understanding Session Termination Causes and RADIUS Termination Cause Codes . It also states to use the show network-access aaa terminate-code command to display the mapping between AAA termination causes and cause code values.

Example

There are almost 600 internal termination codes on MX routers that have enhanced subscriber management enabled: 

root@mx> show network-access aaa terminate-code
Terminate-code:
  Custom Mapping-Count Usage-Count Type
  no     1             0           null
  no     12            0           aaa
  no     5             0           dhcp
  no     364           0           l2tp
  no     210           0           ppp
  no     16            0           vlan

One of the most useful commands is show network-access aaa terminate-code brief , which will show you all entries with non-zero statistics: 

root@mx> show network-access aaa terminate-code brief
Terminate-code:
  RADIUS     Custom Usage-Count Type Code
  6          no     1           l2tp session-receive-cdn
  2          no     1           ppp  lower-interface-down

The most common scenarios for PPPoE subscriber sessions along with the corresponding internal termination code are provided below:

Scenario

Internal termination code

PADT received from CPE ppp lower-interface-down
LCP TermRequest received from CPE ppp lcp-peer-terminate-term-req
No response received for LCP keepalive requests sent by MX ppp lcp-keepalive-failure
"clear pppoe sessions" CLI command ppp lower-interface-down
"clear network access aaa username" CLI command aaa shutdown-admin-reset
"clear services l2tp session" CLI command l2tp session-administrative-close
Tunnel session limit reached (on L2TP LAC/LTS) l2tp session-create-failed-limit-reached
CDN received from LAC/LTS/LNS l2tp session-receive-cdn
StopCCN received from LAC/LTS/LNS l2tp session-tunnel-down
Invalid framed-route value when static route config is enabled via AAA ppp lower-interface-down

Modification History

2022-02-02: Added a new scenario in the Solution section

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