Root login fails when using serial dialup modem

[Rick Stevens]

On Tue, 2007-11-27 at 23:11 -0500, Bill Jones wrote:
>  I'm trying to help someone configure their filesystems using remote
> dialup but the root user login fails when I try to login after the modem
> answers and provides the login prompt. I have ttyS0 in the
> /etc/securetty file. RHEL 4 is the s/w version in question.  It says
> invalid login when I attempt root login. The same login and p/w works
> from the system console. Does anyone have ideas what is causing the
> login to fail?

The first things to check are /var/log/messages and /var/log/secure to
see what's going on.  Specifically, verify that the tty being presented
to login is, indeed, /dev/ttyS0.  Sometimes the name gets mogrified
(e.g. shows up as /dev/modem or some such nonsense).

You should also check to see if you have an /etc/usertty file.  If you
do, check the content and verify there aren't any extra access
restrictions set up.

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- Rick Stevens, Principal Engineer             rstevens at internap.com -
- CDN Systems, Internap, Inc.                http://www.internap.com -
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