System Event Log; Pppoe Mtu Configuration; Platform Considerations - Juniper JUNOSE SOFTWARE 11.0.X - LINK LAYER CONFIGURATION GUIDE 4-1-2010 Configuration Manual

JUNOSe 11.0.x Link Layer Configuration Guide
For more information about configuring RADIUS and L2TP on E Series routers, see
the JUNOSe Broadband Access Configuration Guide.

System Event Log

You can use the radiusSendAttributes system event log category to troubleshoot
applications that use PPPoE remote circuit ID capture. The radiusSendAttributes
event category logs RADIUS attributes added to outbound RADIUS requests.
You can also use the log severity debug pppoeControlPacket command to configure
a packet trace log for a PPPoE interface that includes the PPPoE remote circuit ID
value captured on that interface. For information about how to use the log severity
debug pppoeControlPacket command, see "Troubleshooting" on page 384.
For information about how to log system events, see Overview of System Logging.

PPPoE MTU Configuration

To avoid fragmentation and reassembly, Ethernet access networks require larger
MTU sizes for PPP traffic. With JUNOSe PPPoE MTU, you can control the deployment
of larger packet sizes. You can configure PPPoE MTU directly on the PPPoE interface
or use a dynamic configuration profile. When you use the PPPoE MTU tag, each
PPPoE subinterface can have a unique MTU value. Operational MTU is the lesser of
the PPPoE MTU or the lower layer MTU minus the PPPoE overhead.
You can use the pppoe mtu command to set the MTU using a combination of lower
layer restrictions and controls:

Platform Considerations

You can configure PPPoE interfaces on the following E Series Broadband Services
Routers:
334
Platform Considerations
Issue the radius override nas-port-id remote-circuit-id command to substitute
the remote circuit ID value for the standard NAS-Port-Id [87] RADIUS attribute.
Issue the aaa tunnel calling-number-format command to generate L2TP Calling
Number attribute value pair (AVP) 22 in a descriptive format that includes either
or both of the agent-circuit-id (suboption 1) and agent-remote-id (suboption 2)
suboptions of the PPPoE intermediate agent tags.
Greater MTU than the current maximum permitted by RFC 2516, with the default
equal to the current maximum setting (1494 octets)
Optional setting for absolute maximum PPPoE MTU
Optional use of a larger lower layer MTU
Optional use of the PPPoE-Max-Mtu tag transmitted from the client
E120 router
E320 router
ERX1440 router