RE: [SLUG] login is lost

From: Mikes work account (mrock@stewartsigns.com)
Date: Thu Nov 14 2002 - 14:52:02 EST


Ian,

I have two RH servers and I am checking each against the other for
differences. I added tftp-server to the box that will not accept ftp to
see if that would help and it did not. I have each respected hosts file
populated. I have checked the xinetd.d dir and each is the same with
the exception of the tftp-server entry. That did not show up when I
rpm'd in tftp-server,,,.rpm.
Neither ftp, tftp or gftp works, they just get refused.
Neither box has any ftp daemon running but the first server accepts and
sends ftp requests without error.

As far as the modem connect is concerned,, I have a getty on that line
and when I do a init q,,, the tr light gets lit which tells me that the
modem is getting a signal from the cpu telling it that it is ready to
accept a login. I can connect using hyperlink but I fail to secure a
login prompt which of course dooms my login process entirely. After
about 130 seconds the tr light drops off but the connection stays up (
so sayeth netterm ). Whatever sends the login script is what is dying
for remote connections, either via modem or ssh. It seems that what is
missing is the login script and I do not remember what generates that
piece of code.

As far as DNS is concerned, I have the same problems when I use the ip
addresses and that should bypass DNS if I am correct.

Michael C. Rock
Systems Analyst
Registered Linux User # 287973

"The time has come the walrus said to speak of many things,,,"
"Christians give up what they cannot keep to gain what they cannot lose"

-----Original Message-----
From: slug@lists.nks.net [mailto:slug@lists.nks.net] On Behalf Of Ian C.
Blenke
Sent: Thursday, November 14, 2002 1:41 PM
To: slug@nks.net
Subject: Re: [SLUG] login is lost

On Thursday 14 November 2002 11:46, you wrote:
> Ok, pay close attention now this is going to be fun.
>
> I get a login prompt at the console of my RH 7.2 installation. I get
no
> login prompt if I connect to the box in any other way( via ssh, putty,
> or http). I can ftp from the box to anywhere else, but I cannot ftp
> into the box. I get connection refused.

If you're getting an ftp connection refused, you're not running an FTP
server
in inetd.conf/xinetd.conf or running an FTP daemon standalone.

As for not getting a login prompt, it may be a DNS resolution problem.
If you
wait 5 minutes, does a login eventually appear? Can you run "ssh -v" and

paste the connection log here?

> I have modems connected to a digiboard running off the serial port and
> they will get the terminal light on if I do "init q'. that lasts for
> about a minute and an half and then the TR light drops out.

TR is DTR (Data Terminal Ready). It's the RS-232 line that is held by
the DTE
(Data Terminal Equipment), your PC, when it wishes to be present. A DCE
(Data
Communications Equipment) device asserts DSR (Data Set Ready) when it
starts
up in response to tell the PC that it is present. If DTR isn't there,
the
modem simply will not talk to the port. The same is true from the PC
side to
the modem if DSR is missing. This is at a more basic level than RTS/CTS
hardware flow control. Even 3 wire null modem cables use a loop at both
ends
to trick the DCE/DTE device that the other end is ready.

When the TR light drops out, your PC is typically rebooting.

> If I use hyperlink and try to connect via modem while the modem tr
light
> is lit, I get connected but with not login prompt,, just a blank
> screen,, and no functionality of course.

You need a getty running on that line.

Have you tried debugging with a minicom session on the server with that
port
opened? If you can type on one side and see it on the other (full
duplex, no
local echo), then the serial port settings are fine and the modem is
connected properly.

If you know you have a good connection, you need to enable a getty on
that
/dev/ttyS0 (or whatever your serial device name is). To do this, you
must
edit your /etc/inittab and add a getty for that port.

> Any ideas about what is going on? I have turned off the firewall
> through the setup program and still I am effectively locked out.

Serial is different than network. If you cannot ssh or otherwise connect
to
the box, my bet is that DNS is a problem - try waiting for 5 minutes and
see
if you don't *eventually* get a login.

> And as an aside, samba connections work just fine. But then they do
not
> ask for a login.

Samba connections work, and you can login locally, which suggests that
PAM is
probably fine. My bet is DNS and a lack of a getty on the port.

We need a bit more info/troubleshooting to get a good feel for the
problem.

-- 
- Ian C. Blenke <icblenke@nks.net> <ian@blenke.com>

(This message bound by the following: http://www.nks.net/email_disclaimer.html)



This archive was generated by hypermail 2.1.3 : Fri Aug 01 2014 - 19:54:17 EDT