Re: encap ppp, dialer interfaces and pap posted 01/08/2005
The default encapsulation for the BRI interfaces is HDLC. If you are using
PPP on the dialer you should change it on the Physical as well. You will
notice more than just this doesn't work if you always leave the physical to
----- Original Message -----
From: "Gene Thorne" <gthorne@xxxxxxxxxxxx>
Sent: Saturday, January 08, 2005 7:15 PM
Subject: encap ppp, dialer interfaces and pap
> The ISDN section IE lab 4 uses dialer interfaces. R4 authenticates R5 via
> PAP, and R5 authenticates R4 via CHAP. I set this up with "encap ppp" on
> dialer interfaces and the default encapsulation on the physical
> and entered the appropriate authentication commands. The line came up
> but in looking at the debugs (debug ppp nego) I found that while the CHAP
> authentication worked, the PAP authentication exchange never took place.
> didn't fail, it just never happened. When I put encap ppp on the R4
> interface as well as on the dialer interface, the PAP exchange occurred as
> Is this normal behavior or something peculiar with the 2500s I was using?
> Any rules for deciding when to put the encap ppp on the dialer interface,
> the BRI, or both?
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