Saturday, May 25, 2002

Initial Network reConfiguration

First I merged in the settings from the old /etc/pcmcia/wireless.opt
which wasn't enough to get the Orinoco wireless card working. After
using 'neat' to configure an eth1 wireless device, it came right up.


In /etc/pcmcia/wireless.opt


  • Comment out the section that looked like this:

    essidany,*,*,*)
    INFO="Any ESSID"
    ESSID="any"
    ;;

    Changed the lines in the "Lucent Wavelan IEEE (+ Orinoco, RoamAbout and ELSA)"
    section:

    MODE="Managed"
    ESSID="04502a"
    KEY="s:4502a"


  • Also used 'neat' to allow users enable/disable eth0/1 device.

Install Red Hat V7.3

I wanted to upgrade to fix a galeon problem, unfortunately the Red Hat
upgrade didn't fix the problem. Probably because it didn't upgrade
any ximian'ized packages, so I did a fresh install.

Filesystem Size Used Avail Use% Mounted on
/dev/hda5 1.9G 142M 1.6G 8% /
/dev/hda2 21M 5.7M 14M 28% /boot
/dev/hda6 981M 876M 55M 95% /home
/dev/hda3 2.9G 2.0G 852M 70% /usr
swap 512M

Wednesday, May 22, 2002

GNU/Linux in 20 websites or less

There are a growing number of folks where I work who are getting on
the linux bandwagon. Most of them are coming from a commercial UNIX
background and have questions about how Linux is different, wondering
where to get information, news and software.



Here is my short list of Linux websites for commercial UNIX refugees:








  1. Free Software Foundation -- This
    organization, started by Richard
    M. Stallman
    (better know simply as RMS) and where the acronym GNU
    (GNU is Not UNUX and is pronounced Guh-News) comes from.


  2. The GNU General
    Public Licence
    (aka GPL) and href="http://www.fsf.org/copyleft/gpl-faq.html">Frequently Asked
    Questions about the GNU GPL are two very important pages you
    should read and understand. When people talk about 'free software' in
    this context, they are refering to the freedoms the software is
    licensed under, not the lack of a pricetag. The GPL is the prime
    reason why Microsoft is having a hard time competing with
    GNU/Linux/Open Source software.


  3. The Linux Documentation Project has
    a number of href="http://www.tldp.org/HOWTO/Compaq-Remote-Insight-Board-HOWTO/">
    excellent HOWTO
    documents, longer and
    FAQs on quite a
    number of topics.



  4. Slashdot (also known as
    /.) -- News for
    Nerds, Stuff that Matters
    . This is a great place to
    get a feel for what the hot topics of discussion is in the
    open source/free software world. You can join their daily
    mailing list of news items.



  5. freshmeat.net -- when you
    need to look for open source software. This is an package
    announcement repository. This is very useful if you sort of
    know what you need (say "web log analysis") but don't know
    which packages are available. You can join their daily mailing
    list of new/updated packages.



  6. sourceforge.net -- This
    is a site that provides all the web tools needed to manage an
    open source project -- mailing list, CVS code repositories,
    bug tracking, download servers, etc. Their search engine is
    also very useful for finding particular open source packages.
    Not everyone informs href="http://freshmeat.net">freshmeat of new packages or
    projects.




  7. Linux.com -- A good general
    purpose starting point for information.



  8. openprojects.net --
    While not really a usefull website, they host the very useful
    openprojects IRC chat network. Point a IRC client to
    irc.openprojects.net.
    Useful/interesting channels are #linuxhelp and
    #linpeople


  9. Major Linux Distributions:



    1. Red Hat -- North America,
      worldwide, primary commercial vendor.


    2. SuSE -- Strong European
      presence, known for high quality and very complete distribution
      .
      First distribution to ship six(!) CDs.


    3. debian -- non-commercia
      l
      distribution; has a strong university and world wide following.
      Very
      nice package manager. One simple command to find, download and
      install software for example apt-get install apache.
      To keep
      a system updated to the latest versions, simply apt-get upd
      ate;
      apt-get -u upgrade


    4. Mandrake
      -- North America, worldwide, focuses more on the
      desktop and ease-of-install. A good alternative to
      Red Hat for the novice user.




  10. linuxiso.org --
    "Fresh ISOs like Mom used to Burn". If you are looking to
    download linux installation CDs, this is the one place to go.
    If you don't have broadband, just buy some cheap cds (under
    $5) from one of the many sponsors. Also check out some of the
    niche, but interesting, linux distributions like href="http://brlspeak.net">BrlSpeak for blind users or href="http://k12ltsp.org/ ">K12LTSP which is lets you boot
    diskless workstations from an applications server and is
    perfect for a K - 12 education environment.


  11. Linux Weekly News -- Nice
    roll up of the week's news for the Linux community.



  12. newsforge.net --
    more news from the open source/Linux/BSD/GNU/etc world with a
    more journalistic slant.


  13. thelinuxshow.com
    -- Listen to the weekly Tuesday night webcasts of various open
    source/Linux/BSD/GNU/etc pundits talk about the weeks news.


  14. Of course the best server hardware to run Linux on can be
    found here: HP and href="http://www.compaq.com/linux">Compaq. Also see the
    technical white papers on href="http://activeanswers.compaq.com/aa_asp/Solution_List.asp?str=6-10
    0-225-1">Linux
    solutions.


Friday, April 12, 2002

Blocking ads the simple way

I ran across this little site that describes how to use features in all web browsers to dramaticly cut down on the number of ads you see while surfing. Check out How To Block Ads (& Web Bugs) Without Extra Software. Basically you edit your /etc/hosts file (or equivalent) to direct ad sites to 127.0.0.1.

Wednesday, April 3, 2002

Using ssh and VNC for customer demos


First connect to the demo system and start a vncserver running
there. If you are already logged in, simply vncserver. Or be
fancy and do this from your desktop: ssh your@demo.labsystem.net
vncserver


Now setup an encrypted port redirection using ssh from my desktop to
the demo system. VNC uses port 5901 for desktop :1, port 5902 for
desktop :2, etc.


$ ssh -f -C
-L 5901:127.0.0.1:5901 \
-l marc demo.labsystem.net sleep 7200


Now run a vncviewer on the local machine. Be sure to use the command
switches below which give better performance.


$ vncviewer -compresslevel 9 -encodings "tight copyrect" localhost:1


Now have your field person also create a ssh port tunnel (of course
they need an account on the demo system as well) and also run
vncviewer. Now both of you can control the keyboard and mouse for the
system. The performance can be surprisingly good if you have a least
T1 speeds. Across a slower DSL, it is usable, but you feel the delay.

Using ssh to pierce corporate firewalls



I work for a company that has firewall that only allow out http, https and most importantly, ssh. While at my desk I want to check mail home IMAP4 mail, VNC to our lab systems on an external network, check in on an IRC chat room or even surf to some sites that I don't want corporate IM to know about. (I'm not talking porn, but the nanny software frequently blocks sites as 'hacker sites' like the nmap site which I do have a business reason to be viewing. Ugh.)

So I use ssh's port redirection to do all this.


ssh -f -C \
-L 1234:mail.myisp.com:143 \
-L 6667:irc.openprojects.net:6667 \
-L 8080:127.0.0.1:3128 \
-l marc homemachine.dslprovider.com sleep 7200


Then I configure my mail client to connect to localhost:1234 for IMAP, chat client to use localhost:6667 and web browsers to use localhost:8080 for proxy. Just so I don't have to go reconfigure all the apps that need to use a proxy (mozilla, netscape, galeon, konqueror, Ximian's red-carpet, Red Hat's up2date, nautilus and various command line apps that use http_proxy like debian's apt-get, etc) they always use 'localhost:8080' for the web proxy. When I want to switch back to using the corporate firewall, I run this instead:


ssh -f -C
-L 1234:mail.myisp.com:143
-L 6667:irc.openprojects.net:6667
-L 8080:proxy.whereIwork.com:8080
-l marc homemachine.dslprovider.com sleep 7200

Tuesday, April 2, 2002

Using ssh and VNC for customer demos


First connect to the demo system and start a href="http://www.uk.research.att.com/vnc/">vncserver running
there. If you are already logged in, simply vncserver. Or be
fancy and do this from your desktop: ssh your@demo.labsystem.net
vncserver


Now setup an encrypted port redirection using ssh from my desktop to
the demo system. VNC uses po
rt 5901 for desktop :1, port 5902 for
desktop :2, etc.


$ ssh -f -C \
-L 5901:127.0.0.1:5901 \
-l marc demo.labsystem.net sleep 7200


Now run a vncviewer on the local machine. Be sure to use the command
switches below which give better performance.


$ vncviewer -compresslevel 9 -encodings "tight copyrect" localhost:1


Now have your field person also create a ssh port tunnel (of course
they need an account on the demo system as well) and also run
vncviewer. Now both of you can control the keyboard and mouse for the
system. The performance can be surprisingly good if you have a least
T1 speeds. Across a slower DSL, it is usable, but you feel the delay.