Sysadmin help needed !

[Robin Wilson]

In article <1990Sep27.030149.13622 at portia.Stanford.EDU> glowell at portia.Stanford.EDU (gary lowell) writes:
>1.  Configuring serial ports.
>

The problem here is likely to be with the Telebit setup.  Given the 2
suggested methods of setting up a tty for bi-directional use, there are
a number of possible problems that can arise from mis-understanding what
transpires in the login/terminal use attempt.  

	1) PDELAY (or just delay) -- can be used for bi-directional
	serial port usage (or any port for that matter... including 
	/dev/hft/0 -- the console).  In this mode, the port starts a
	getty process on the tty and tells getty to 'wait for a 
	character to arrive on the input buffer'.  When getty starts
	DTR is raised, and the modem should be able to go into 
	'autoanswer' mode.  However, if the modem is set with DTR 
	strapped high (AT&Dx -- hayes command set, or one of the 'S'
	registers on the Telebit enhanced command set) (forgive me if
	I am not precise about some of this, I am not at work right now
	where I have all of the docs in front of me for the TB+) it 
	will already be in autoanswer mode, so having our getty raise 
	DTR will accomplish nothing (assuming S0<=001).  Also, if the
	'incoming call response' is set to echo call activity to the 
	DTE (in this case the RS/6000) (hayes command set 'Q' register --
	TB extended command set '??' register (probably Q as well)), 
	then incoming calls will echo "RING" everytime a call is 
	received.  This will cause getty to fire up a login process and
	issue a login herald.  IF THE LOGIN HERALD BEGINS ECHOING TO 
	THE MODEM BEFORE CARRIER IS ACHIVED, THE MODEM WILL GO ON HOOK
	because it thinks someone is attempting to issue a command
	locally.  The solution is to set the command response to 'Q6'
	on the hayes command set, and the equivalent for the extended
	command set.

	2) PSHARE (or just SHARE) -- is intended for bi-directional
	tty usage as well.  However, the getty running on this process
	works a little differently than PDELAY.  Getty on a shared port
	waits to see carrier come high on the tty it is watching (EIA
	standards define pin 8 of a DB-25 connector to be used for 
	carrier).  The telebit signals carrier by either turning on 
	the fast or slow connection lights, depending on the connection
	speed.  When getty sees carrier come high it issues a login
	process, and herald.  If the TB has carrier strapped high (hayes
	command set &C0, extended command set S52=000 (I think, but you 
	better check)) then getty will always see carrier, and immediately
	send a herald.  You should set carrier signalling to follow true
	carrier (hayes - &C1, TB - ?? can't remember... just look in the 
	quick setup guide).  

	3) PENABLE (ENABLED) -- is intended for all other terminal usage.
	getty starts up and issues a login process immediately, and the
	corresponding herald.

	You will also want to set your modem up with DTR to follow EIA
	standards (hayes - &D2, extended ??) and DSR to follow standards
	(hayes - &S1, extended ??).  This will insure that the port can
	properly disconnect when the process running on it terminates.
	The tty will also probably need to have 'stty attributes at LOGIN'
	include 'hupcl,'.  This will insure that the port disconnects after
	getty terminates on 3 incorrect logins.  The game is different if
	you are using the tty for a slip connection, so I won't touch that
	here.  see if this stuff helps any for now.
>
>2.  User Logins.
>
I'm not real sure, but I believe that there is a security feature on the 
USERS side of SMIT that you will need to double check...  I just can't 
think of it right now.  It is best to double-check the "change" user screen
on smit, and get to know each field of the user entry.  Also, make sure that
the users don't have a password of "*" in /etc/security/passwd.  Just because 
"su" works doesn't mean that the account is useable as a login account (this
is just a hunch, but by saying that the accounts work OK on the hft, do 
you mean you can "su" to them??  please don't take this the wrong way, I 
>3.  Escape in csh and ksh
>
I don't know about "csh" (since I never use it), but for "ksh" to use 
ESC for things like command line editing, you must first define an EDITOR
environment variable.  This can be accomplished with: "export EDITOR=<your
favorite editor here -- mine is /usr/bin/vi>" or "set -o /usr/bin/vi".  I
imagine the "set -o" will also work on "csh".


Robin D. Wilson.. Working for, but not officially representing to USENET
IBM Level 2 Field Support.