Support Support Downloads Knowledge Base Juniper Support Portal Community

Knowledge Base

Search our Knowledge Base sites to find answers to your questions.

Ask All Knowledge Base Sites All Knowledge Base Sites JunosE Defect (KA)Knowledge BaseSecurity AdvisoriesTechnical BulletinsTechnotes Sign in to display secure content and recently viewed articles

[ScreenOS] PPPoE connection terminates every 5-15 seconds



Article ID: KB8561 KB Last Updated: 29 Mar 2019Version: 4.0

PPPoE Internet connection dropping every 5-15 seconds. Increase the lcp-echo-retries and lcp-echo-timeout parameters.


The Event Log on the firewall was reporting PPPoE connection drops every 6 sec.

Customer’s configuration for PPPoE was as follows:

set pppoe name "untrust" idle 0
set pppoe name "untrust" interface untrust
set pppoe name "untrust" ppp lcp-echo-retries 1
set pppoe name "untrust" ppp lcp-echo-timeout 6
set pppoe name "untrust" auto-connect 1
set pppoe name "untrust" clear-on-disconnect

The above configuration specifies the firewall will send an LCP Echo Request to server every 6 seconds to check if it is alive or not.
After a single attempt, if no reply is received it will drop the connection.
These values are very aggressive keepalive parameter settings.

The default values and definitions of these parameters are as follows:
  lcp-echo-retries        the number of unacknowledged LCP Echo requests before connection is terminated. Valid range is 1-30. The default is 10.
  lcp-echo-timeout      the time that elapses between transmission of two LCP Echo requests. Valid range is 1-1000 seconds. The default is 180 seconds.

Increase the lcp-echo-retries and lcp-echo-timeout parameters:

set pppoe name "untrust" ppp lcp-echo-retries 10
set pppoe name "untrust" ppp lcp-echo-timeout 10

For this customer, the PPPoE/Internet connection was stable after setting both parameters to a value of 10.

Modification History:
2019-03-29: Article reviewed for accuracy. No changes made.
Comment on this article > Affected Products Browse the Knowledge Base for more articles related to these product categories. Select a category to begin.

Getting Up and Running with Junos

Getting Up and Running with Junos Security Alerts and Vulnerabilities Product Alerts and Software Release Notices Problem Report (PR) Search Tool EOL Notices and Bulletins JTAC User Guide Customer Care User Guide Pathfinder SRX High Availability Configurator SRX VPN Configurator Training Courses and Videos End User Licence Agreement Global Search