Ask Shadowman


July 2003

Dashing, daring, and debonaire. Known by one name like Napoleon or Tigger. Nobody does it better, makes you feels sad for the rest. Nobody does it half as good as him. Baby... he's the Shadowman. He's also on vacation, so this month, we're giving you a taste of "The Best of Ask Shadowman"

Got a question that you'd like Shadowman to answer? Ask him.


Brian M. writes:
I tried using 'tcpdump' and got some interesting info I don't understand. 192.168.0.2 is my linux box, 192.168.0.254 is the router.

-> 23:38:17.562019 eth0 > arp who-has 192.168.0.254
tell 192.168.0.2 (0:50:ba:be:59:65)
-> 23:38:17.562019 eth0 < arp reply 192.168.0.254
is-at 0:0:c0:51:e8:c1 (0:50:ba:be:59:65)
-> 23:38:17.562019 eth0 > 192.168.0.2.1025 >
192.168.0.254.domain: 53518+ A? www.rhns.redhat.com.
(37) (DF)
-> 23:38:22.572019 eth0 > 192.168.0.2.1025 >
192.168.0.254.domain: 53518+ A? www.rhns.redhat.com.
(37) (DF)
-> 23:38:27.582019 eth0 > 192.168.0.2.1025 >
192.168.0.254.domain: 53519+ A?
www.rhns.redhat.com.Ourhouse. (46) (DF)

This goes on for many more packets - I didn't post whole thing due to length, but can provide. Can someone tell me why my computer is 'calling home?'

Shadowman says:
Shadowman is impressed -- the very first question, and it includes a packet trace! (With questions like this, Shadowman wonders if it's too late to go back to just being another pretty face here in Red Hat HQ...)

But first, a little background before answering your question. The first thing to keep in mind about Red Hat Network is that it is based on a client/server architecture. Basically, that means that the client (your system) must connect to the server (the Red Hat Network systems) in order to make anything happen.

It's always the same dance:

  1. client "asks"
  2. server "answers"

But sometimes, you want the server to start the conversation--like when Red Hat Network determines that an update should be installed on your system.

How do you make this scenario fit into the client/server architecture? The short answer is that you don't--the client-server model doesn't support it. So a different approach is necessary; and that's what you're seeing.

In this case, your system has been profiled and registered with Red Hat Network. Once that is done, your system will "check in" with the Red Hat Network on a periodic basis, looking for updates and actions to be performed. If there is an update or action available for your system, this periodic check will discover them, making it look like your system was actually "tapped on the shoulder" by Red Hat Network.

If you temporarily want to stop this from happening (say you're sitting in a hotel room in Dubuque reading email on your laptop, and the modem's just connected at 4800 baud, and you *really* don't want that nifty 100MB XFree86 update downloading right now, thank you very much), just enter this command (while logged in as root, of course):

/sbin/service rhnsd stop

You can also disable it forever with another command (again, as root):

/sbin/chkconfig --del rhnsd

Whew! Shadowman needs a vacation after that one...


Mike B can't live another day without knowing:
How can I access my NTFS volumes in RedHat?

Shadowman says:
Shadowman keeps hearing about this NTFS thing, and decided to let you all have it. Replete with a quick primer on recompiling your kernel, for those who care to learn once in awhile.

Make sure the following packages are installed:


kernel-headers	glibc		binutils
kernel-source	kgcc		gcc
dev86		cpp
make		ncurses-devel
You are changing the kernel, and may want the numbering to reflect that. So edit /usr/src/linux/Makefile and change your EXTRAVERSION (e.g. Change -18 to -18ntfs).
cd /usr/src/linux

cp -p configs/kernel-*-i686.config arch/i386/defconfig 
(change i686 to the appropriate processor)
make mrproper
make oldconfig
make xconfig (config or menuconfig if not in X)

And enable ntfs support under file systems.
make dep bzImage 
(this should create System.map and arch/i386/boot/bzImage)

make modules

cp -p arch/i386/bzImage /boot/vmlinuz[version]
cp -p System.map /boot/System.map-[version]
make modules_install
If you have scsi, don't forget to create a new initial ramdisk:
mkinitrd /boot/initrd-[version]
Edit lilo.conf to reflect the new kernel addition (leave the other stanzas in tact until you are sure it boots) and run lilo, or add the line to grub.conf in the syntax of the other lines.

This will enable "read" support for your ntfs volumes. Write has never, and likely will never work well enough to be safe at any speed. You may have to have a vfat partion as a way station for interim writes.

You should now be able to mount your ntfs partitions, or create an fstab entry to do it each boot.


Rob S. awoke from 20 years slumber to find a long white beard and this question:
I am the administrator of a windows 2000 network. All the servers and clients are windows 2000. I have purchased a copy of red hat 8.0 and would like to place this on the network as a client. I have no experience of linux whatsoever and would like to find a simple walkthrough from start to finish on how to accomplish this, if it is possible.

Shadowman says:
Shadowman is going to make an ass out of u and me and fill in some gaps. Let's assume that you are running DHCP. Let's assume you are using Windows as the primary domain controller. Go ahead and do an everything install of 8.0, it saves time picking packages, but takes longer to install, and eats more disk space. This is from Shadowman's assumption that you are independently wealthy and are flush with free time and disk space.

Once installed, boot up. Double click the home directory on your desktop and type smb:// in the location field and hit enter. If all went well you should see some Windows machines. If all went really well you'll see the new Linux box on your Network Neighborhood from Windows. There are of course other things to do, most of which are documented in mind numbing detail at The Linux Documentation Project (http://www.tldp.org/) or, if you prefer print, grab Running Linux by O'Reilly and Associates.

I know this was intended as a client, but since you did an everything install, unplug all of the Windows 2000 servers. You're free! Now go and help the others.


In short:

To Bill S. and Keith F, who wanted to know about browsing SMB/Samba shares in Linux, Shadowman says: Use Nautilus. smb:// will browse the network and display the shares (you can click the icons to access) or use smb://servername/sharename.

To Micah L, who wanted to know where screen-shooter went, Shadowman says, print screen and alt-printscreen work just fine.

To Alvin T., who wanted to know how to do better with the ladies, Shadowman says: 1) Be genuine. 2) Be attentive. 3) Get yourself a snappy hat.