Discuss August 2006

discuss@lists.centos.org

269 participants
332 discussions

connecting linux console using serial port (NOW PPP)
by israel.garcia＠cimex.com.cu 18 Aug '06

18 Aug '06

Alex, thanks for your soon answer, but in case I want to configure PPP on this server, what files do I have to configure? Can I login in this server using SSHD over a PPP conection? Regards; Israel > Just terminal access -> I want to login in my linux server connecting > through the modem connected in /dev/ttyS0 Not sure if this is complete. Install mgetty if not already present on your system. Go to /etc/mgetty+sendfax directory. If you have CallerID feature on your phone line (and you should get it if you don't have it yet), edit dialin.config file and add telephone numbers you will be dialing from. At least this will prevent clueless script-kiddies from getting login prompt on your modem line. I know that some of my modems get regullary probed from strange phone numbers (and those are dedicated modem lines -- no voice calls on them, not listed in white pages, too often on too many lines to be the simple case of wrong number). While there, check login.config file. If you don't want PPP on it, make sure /AutoPPP/ is commented (should be default). Make sure "* - - /bin/login @" line is not commented (should be last line in the default config file). That's the line that will give you login prompt. Edit /etc/inittab and add something like this: s0:2345:respawn:/sbin/mgetty -D -n 2 -s 115200 /dev/ttyS0 The "-n 2" tells mgetty to pick up the phone after second ring. You need to wait till second ring because telephone company sends CallerID information between first and second ring. If you configured mgetty to answer after first ring, it would never get CallerID information. Execute "telinit q" as root (this tells init process to reread inittab file). Configure and connect modem and you should be set to go. I do not recommend allowing root to login directly from modem line (could be configured by editing /etc/securetty and /etc/security/access.conf files if needed, but not wise idea). Login as normal user, than su to root. --

2 1

connecting linux console using serial port
by israel.garcia＠cimex.com.cu 18 Aug '06

18 Aug '06

uoting israel.garcia at cimex.com.cu: > Hi, I have a serial modem connected to /dev/ttyS0 on my CentOS server, I > want to set up this server to allow connections through this serial > modem but only to the console.... (I want to log in)... > > PS: I don't want PPP, I just want to get my linux console through this > serial modem... > > What do I have to configure on my linux? >Hmmm... Do you want *console* (as in /dev/console) or just terminal >access (as in /dev/ttySO)? Just terminal access -> I want to login in my linux server connecting through the modem connected in /dev/ttyS0 -- NOTICE: If you are not intended recipient, you are hereby notified that by reading this message you agreed not to disturb frogs during mating season. For more info, visit http://www.8-P.ca

2 1

new centos 4.4 kernel
by Jerry Geis 18 Aug '06

18 Aug '06

I have heard rumblings about the new kernel for 4.4 A change was made to the kernel for disk I/O to make it better/faster. I havnt heard/seen anything about what that really translates to. Any thoughts/opinions on this. jerry

4 4

RE: Re: [CentOS] connecting linux console using serial port
by pctech＠mybellybutton.com 18 Aug '06

18 Aug '06

>Quoting israel.garcia(a)cimex.com.cu: > >> Hi, I have a serial modem connected to /dev/ttyS0 on my CentOS server, I >> want to set up this server to allow connections through this serial >> modem but only to the console.... (I want to log in)... >> >> PS: I don't want PPP, I just want to get my linux console through this >> serial modem... >> >> What do I have to configure on my linux? > >Hmmm... Do you want *console* (as in /dev/console) or just terminal >access (as in /dev/ttySO)? > The easy way is to configure the modem so that it is in Auto-Answer mode all of the time. Once it is in auto-answer mode it will answer when you dial it and then you will see what the is transmitted to it via the serial cable. Then follow the instructions for setting up Linux to use the serial port for output/input. If you don't have that information at your fingertips it is as follows: 2.3 Configuring Headless Operation By configuring “headless” operating we will be able to manage the system via a cable plugged into the serial port of the system. This obviates the need to plug a keyboard and monitor into it to perform changes. Thus the term “headless”. 2.3.1 Changes to /etc/inittab The /etc/inittab file contains settings that get applied to the Operating Systems at boot time. There are some changes that need to be made to these settings. In order to edit the /etc/inittab file type: vi /etc/inittab Typing this command will open the /etc/inittab file for editing. As stated earlier the 18th line down is the run level line. Add the following line to the file: S0:12345:respawn:/sbin/agetty 9600 linux This line sets the Operating System to be able to send boot time information to the serial port in addition to the console. After you have made these changes to the /etc/inittab file press the colon (: ) key and then type wq to quit vi and save the changes. 2.3.2 Changes to /etc/securetty The /etc/securetty sets the controls for which TTY devices that the root account can log on via. In order for us to be able to log onto the serial console as root or to be able to su to root we must add a line to the file. In order to edit the /etc/secuertty file type: vi /etc/securetty Typing this command will open the /etc/secuertty file for editing. Add the following line to the end of the file: ttyS0 This line sets the Operating System to allow root to log on to the serial port in addition to the console. After you have made these changes to the /etc/securetty file press the colon (: ) key and then type wq to quit vi and save the changes. 2.3.3 Changes to the Boot Loader In order for boot-time messages to be sent to the console, including the boot loader information some changes must be made to the configuration file for it. The boot loader that CentOS uses is GRUB. As such, the configuration file is /etc/grub.conf. The first change that we must make is to add some lines after the timeout line in the GRUB configuration file. In order to edit the /etc/grub.conf file type: vi /etc/grub.conf Typing this command will open the /etc/grub.conf file for editing. Add the following two lines after the timeout line in the configuration file: serial --unit=0 --speed=9600 terminal --timeout=5 serial console Another change that we must make in the GRUB configuration file is to tell the kernel to send out all kernel-level messages to the serial port in addition to the console. That is done by adding the following line to the end of the kernel line: console=tty1 console=ttyS0 After you have made these changes to the /etc/grub.conf file press the colon (: ) key and then type wq to quit vi and save the changes. Once you have made these changes reboot the system by typing by typing: reboot The system will now reboot. >-- >NOTICE: If you are not intended recipient, you are hereby notified >that by reading this message you agreed not to disturb frogs during >mating season. For more info, visit http://www.8-P.ca/ > >_______________________________________________ >CentOS mailing list >CentOS(a)centos.org >http://lists.centos.org/mailman/listinfo/centos

1 0

connecting linux console using serial port
by israel.garcia＠cimex.com.cu 18 Aug '06

18 Aug '06

Hi, I have a serial modem connected to /dev/ttyS0 on my CentOS server, I want to set up this server to allow connections through this serial modem but only to the console.... (I want to log in)... PS: I don't want PPP, I just want to get my linux console through this serial modem... What do I have to configure on my linux? Thanks for your time Regards; Israel

2 1

change default columns in init 3?
by Yiorgos Stamoulis 18 Aug '06

18 Aug '06

Hello list, How can I change the init 3 shell default $COLUMNS ? (I am trying to wean myself from GUI) Thanks

3 6

Netdump
by bruce 18 Aug '06

18 Aug '06

hi... has anyone ever used netdump?

2 2

Tomcat Virtualhost Question
by John Hinton 18 Aug '06

18 Aug '06

I have tomcat up and running (manager operational) and am serving genuine Apache Tomcat Error Reports from a virtualhost. :) So, it looks like I'm good up to the point of creating a WEB-INF directory inside of the virtual docroot. Can someone tell me how this should be done? Permissions.. contents.. or if I'm just supposed to pull this from somewhere in the Tomcat installation? I have googled my butt off and not found a thing about how this directory should be created. Thanks, John Hinton

1 0

Upgrading GFS/RHCS for CentOS
by carlopmart 18 Aug '06

18 Aug '06

Hi all, Somebody knows when RHCS and GFS kernel dependant packages will be upgraded to use it with kernel version 2.6.9-34.0.2?? I nee to update my kernels due to security policy on my company and recent vulnerabilities discovered .... many thanks. -- CL Martinez carlopmart {at} gmail {d0t} com

1 0

CentOSPlus kernel - Request for input
by Jerry Geis 18 Aug '06

18 Aug '06

Johnny, If you could change the following config in the new kernel: Device Drivers -> Character Devices -> Serial Drivers change Max number of 8250 serial ports from 4 to 36 change Number of 8250 serial ports to register at runtime from 4 to 36 Thanks, jerry

2 2

← Newer
1
...
14
15
16
17
18
19
20
...
34
Older →

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

Discuss August 2006