System Event Log; Pppoe Mtu Configuration; Platform Considerations - Juniper JUNOSE SOFTWARE 11.2.X - LINK LAYER CONFIGURATION GUIDE 7-7-2010 Configuration Manual

JunosE 11.2.x Link Layer Configuration Guide

PPPoE MTU Configuration

Platform Considerations

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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 434.
For information about how to log system events, see Overview of System Logging.
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:
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
You can configure PPPoE interfaces on the following E Series Broadband Services Routers:
E120 router
E320 router
ERX1440 router
ERX1410 router
ERX710 router
ERX705 router
ERX310 router
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