"No auth is possible" problem during ppp connection

Moe Trin

2008-02-26 19:15:31 UTC

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On Mon, 25 Feb 2008, in the Usenet newsgroup comp.protocols.ppp, in article

Post by marufloor
helps, i can't ppp connection.

The options you have chosen are wrong.

Post by marufloor
I think <auth chap MD5> problem.
I don't know why received message is No auth is possible

You have told pppd not to allow PAP or CHAP authentication, but the
system you are connecting to _requires_ one or the other.

Post by marufloor
platform : Linux Redhat Enterprise 4 AS.

That's about three years old - probably using ppp-2.4.2 or 2.4.3. See
the man page for pppd, which gives more information on the options.

Post by marufloor
exec /usr/sbin/pppd debug \
/dev/ttyS0 9600 \

Do you know that you need such a slow speed? Most modems today will
operate at 115200

Post by marufloor
lock \
noauth \

'noauth' is not requiring the peer to authenticate to you - normally
this is the default unless '/sbin/route -n' shows a default route
before you try to dial in.

Post by marufloor
noccp \
nomagic \

These should probably not be there

Post by marufloor
refuse-chap \

This is one of your problems. Why do you refuse to tell the peer who
you are?

Post by marufloor
defaultroute \

Post by marufloor
asyncmap 0 \

This is the default, but the peer is asking for 0xa0000 and that is
often a sign that the peer is broken and you should use the same value.

Post by marufloor
-crtscts \
-ac \
-vj \
-vjccomp \
-detach \

These are obsolete options (changed in ppp-2.3.0 back in 1997, and
probably not a good choice. Remove them, and add 'nodetach' only.

Post by marufloor
-d \

Obsolete - use 'debug' if needed.

Post by marufloor
-bsdcomp \

Obsolete - not needed, as 'noccp' disables all data compression.

Post by marufloor
-chap \
-pap \

And again - obsolete options, but this is the cause of the "No auth is
possible" message. You are refusing all authentication.

Post by marufloor
#!/bin/sh
/usr/sbin/chat -v \
TIMEOUT 6 \
ABORT '\nBUSY\r' \
ABORT '\nNO ANSWER\r' \
ABORT '\nRINGING\r\n\r\nRINGING\r' \
'' \\rAT \
'OK-+++\c-OK' ATM1L3 \
TIMEOUT 30 \
OK ATDT$TELEPHONE \
CONNECT ''

I know that is part of the ancient HOWTO, but no one has been using
that script in many years. Also, this is not initializing the modem
(see the manual for the modem). Perhaps a more suitable script would
be

#!/bin/sh
/usr/sbin/chat -v \
ABORT BUSY \
ABORT 'NO ANSWER' \
'' AT&F0 \
OK ATDT$TELEPHONE \
CONNECT \d\c

The 'AT&F0' is a common modem initialization command - although some
modems (US Robotics) want AT&F1.

Post by marufloor
http://korea.gnu.org/people/chsong/klug/linux-kr.org/PPP-HOWTO.html#toc27

The document is the Korean translation, and I can not read it. However
the PPP-HOWTO was last updated in July 2000, and the section you appear
to be following is much older and is obsolete. I suspect this version
may be from March, 1997 and is nearly useless.

Post by marufloor
but, ppp connection success on Windows xp platform.
follows ppp connection options on window
- disable 'HARDWARE FLOWCONTOL'

That is very unusual with most modems.

Post by marufloor
- disable 'LCP extention'
- disable 'Software compress use'
- disable 'IP Compressed Header use'

Normally, I would recommend letting pppd make the correct decision
regarding these issues. The 'LCP extention' is a microsoft concept
and not really implemented in Linux. Software and IP Compressed
Headers should negotiate correctly. Only if they do not (shown by
errors in the ppp log) should you try

noccp
novj

Old guy