PPPoE: PADR size

Unanswered Question
Jan 24th, 2008


We have a problem with the connection of several CPEs (non-cisco).

these CPEs sends a PADR with a size of 129 bytes, then our concentrator (7200) doesn't accept the connection:

Jan  7 09:27:25.325: [818]PPPoE 397: Service request sent to SSS

Jan  7 09:27:25.325: [818]PPPoE 397: Larger than supported PADR (size 129) R:0012.ef04.c99f L:0007.84ea.b806 3458 Fa0/1.3458

Jan  7 09:27:25.325: [818]PPPoE 397: Destroying  R:0012.ef04.c99f L:0007.84

ea.b806 3458 Fa0/1.3458

What's the maximum size of PADR?

Is this PADR size described in the standard or in Cisco Documentation?

Is this limitation solved in any version or platform?

Any method for allow a greater PADR?

Thanks and regards.


I have this problem too.
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jyubero Wed, 01/30/2008 - 08:40


It's not a problem with the MTU (we have configured the MTU as 1492, and we adjust the MSS).

The problem happens at the pppoe client session initiation (PADI,PADO,PADR,PADS).

The PADS (that a CPE send) seems to be bigger than the supported size. This size is 129 bytes (149 bytes with ethernet tag).

We want know what is the limitation of PADS size for Cisco? if this is an standard limitation? or if exist an IOS or platform without this limitation?

Thanks and regards.



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