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reading/writing floppy disk

by Gregory Avedissian

I'm a little confused. Do I have to mount and unmount /dev/fd0 every time I want to look at a different floppy disk? Is there a less cumbersome way to do this? Thanks. Greg

Feb. 17, 2002

apt-get across multiple computers

by David Lee Ludwig

I am currently helping to manage a small network of Linux workstations, each of which runs Debian. Given that each workstation has a good amount of hard disk space on it, I generally keep software installations local. Additionally, most of the software on these machines is managed via Debian's apt system. I'm looking for an easy way to get apt-get functionality across these workstations (all run the same version of Debian.) More specifically, I want a distributed version of "apt-get install". Does anyone know of a pre-built set of scripts/tools that will allow me to do this, or am I going to have to write my own? -- David Ludwig | "The Linux philosophy is laugh in the face of davidl<at>wpi.edu | danger. Oops. Wrong One. 'Do it yourself.' http://www.oflove.com | That's it." - Linus Torvalds

Feb. 17, 2002

Re: [Wlug] network questions

by doug waud

"bryon3245(a)netzero.com" wrote: > > What firewall under linux would you suggest, > what would the best way to set up a firewall-router box with two nic's? I suspect this depends upon the distro. I recently upgraded my gateway box from SuSE 6.3 to SuSE 7.2 and found that the default "Personal Firewall" was exactly what I wanted. (I just use the web for browsing and email so all my connections are started by me and so can easily be "masqueraded" --- hidden from the web). It seems to give you essentially the same thing as that Linksys box Steven Daukas (is that a real name?) suggested --- basically masquerading stuff coming from within and blocking anything unrelated from outside. Again, setting up the nic's is the same with all distros if you approach at the under the hood level but will differ if you use their administrative tools since the latter again are distro dependent. In the SuSE case, their Network Manual, pp 149 guides you through reasonably painlessly while still providing some idea of what is going on. Now, all bets are off if you want to provide some service like a web site or ftp server because then you have to do more than just masquerading and that does require you to become more familiar with how a firewall works. As to the two nics, basically you will set up one, say eth0, which is connected to your cable/dsl modem as a dhcp client which will get its ip address from the isp (I assume that, since you are asking a basic question, you did not spring for a fixed ip address which is more expensive; I also assume that you have a broadband connection since you specify two nics). The other nic, say eth1, you set up with a fixed IP address on your local net, for example, 192.168.1.1. If, at this point, your head is swimming, you can either look at the slides from an old WLUG presentation on networking (go to WLUG site, find "Past meeting information" and go to the March 2001, stuff. Slides 47 and 48 give a back to basics summary of the difference between a hub and a switch incidentally) or look into the manual(s) that come with your distro and see if they are as useful as those for SuSE or, get back to me (I suggest directly so we do not clutter the WLUG mail list more than I have been doing lately :-) ) and I am quite willing to try to walk you through the process on a slower one-on-one step-by-step process. The hazards here are that (1) I can easily get in over my head (but, I believe, am willing at least to let you know when that happens) and (2) you may end up wishing as in the Tom Lehrer song "You should never have let me begin ... " :-) doug

Feb. 17, 2002

Re: [Wlug] network questions

by Stephen C. Daukas

I have both hubs and switches and, unless you care about running your own servers and other issues not normally associated with a home network, for example, then you won't notice any difference. Basically, with one or two machines and a cable modem, for example, there is no practical difference in my opinion. Having said that, I have switches because I got three switches at a computer show for less money than a hub would have cost, and I'm running several servers and workstations, and doing a lot of other stuff that isn't necessary, but is fun if you have the stuff to play with... As far as firewalls go, I would recommend buying something like a linksys router/firewall (<$100) if all you care about is getting up and going quickly (if that's what you were asking). I say this only because once you get the router configured, you don't have to bother with it unless you want to go to the next step (which may be a good idea depending on your needs). You don't have to worry about messing anything up while playing with the next kernel release, or whatever. In other words, it is separate from any other activity you may plan for that machine, and safe from any "mistakes" along the way. For those who enjoy the trip, so to speak, or for those who want better control over their firewall, I would get "Linux Firewalls" second edition, by Robert L. Ziegler, and take it from there. It covers packet filtering, iptables, perimiters, NAT, and other useful items. This book will also cover specific questions regarding hardware and software configurations. I started with a Linksys and am building my own firewall now. I plan on using the Linksys as part of the total configuration of my home network - not because I need it, but because I have it and I figure it will be fun to play... (See Paragraph 2). ;-) Regards, Steve At 10:23 PM 2/16/2002, you wrote: >I have a couple of questions. Why would you want a hub over a >switch? What firewall under linux would you suggest, what would the best >way to set up a firewall-router box with two nic's? > >Thanks for you'r help > >-------------------------------------------------------------------- >mail2web - Check your email from the web at >http://mail2web.com/ . > >_______________________________________________ >Wlug mailing list >Wlug(a)mail.wlug.org >http://mail.wlug.org/mailman/listinfo/wlug

Feb. 17, 2002

Re: [Wlug] network questions

by Charles R. Anderson

A switch also allows you to use Full-Duplex communication on your ethernet cards. When using Full-Duplex, there are no collisions. This is most helpful when a lot of packets are being sent between the computers on the switch, such as when using NFS or X Window System traffic between computers on your LAN. -- Charles R. Anderson <cra(a)wpi.edu> / http://angus.ind.wpi.edu/~cra/ PGP Key ID: 49BB5886 Fingerprint: EBA3 A106 7C93 FA07 8E15 3AC2 C367 A0F9 49BB 5886

Feb. 17, 2002

Re: [Wlug] network questions

by Bill Smith

On Sat, 16 Feb 2002 22:23:26 -0500 "bryon3245(a)netzero.com" <bryon3245(a)netzero.com> wrote: > I have a couple of questions. Why would you want a hub over a switch? a hub is inexpensive. what is seen on one port is (generally) seen on all the others. if security is not an issue and you don't have huge amounts of traffic on your LAN, then a hub is a reasonable choice. switches tend to be a little more expensive because of the nature of their operation. they usually work by learning which ports are used when the computers communicate, so when communication happens after the first time, the information is handled a bit faster. the nice thing here is that once that traffic pattern has been learned, nobody else on the switch sees those packets, unless they are connected to those ports. if you are interested in playing with VLANs, you'll need a switch. there aren't any plain hubs that i am aware of that are smart enough to do more than repeat VLAN packets. Hope this helps... -- +--------------------------------------------------------------+ | William Smith wsmith at chezsmith dot com | | Fall River, MA http://www.chezsmith.com | +--------------------------------------------------------------+ | "Outlook not so good." That magic 8-ball knows | | everything! I'll ask about Exchange Server next. | | * TAG! v2.2 * | +--------------------------------------------------------------+

Feb. 17, 2002

network questions

by bryon3245＠netzero.com

I have a couple of questions. Why would you want a hub over a switch? What firewall under linux would you suggest, what would the best way to set up a firewall-router box with two nic's? Thanks for you'r help -------------------------------------------------------------------- mail2web - Check your email from the web at http://mail2web.com/ .

Feb. 17, 2002

Re: [Wlug] Newbie Answer.

by doug waud

doug waud wrote: too much :-) I thought I was writing to Andy and somehow wasted everyone's time Meanwhile, Frank Sweetser has summarized the situation well. doug

Feb. 16, 2002

Re: [Wlug] Newbie Answer.

by doug waud

> The reason that /etc/init.d/boot.local and /etc/rc.d/boot.local are the > same file is because /etc/rc.d is a link to /etc/init.d on my SuSE 7.2 PRO > system. > > linuxpc> ls -ald /etc/rc.d > lrwxrwxrwx 1 root root 6 Mar 24 2001 /etc/rc.d -> init.d Been there, done that :-) Actually, I tried root@233p5:/ > ls -al /etc/init.d/boot.local -rwxr--r-- 1 root root 447 Jan 30 16:37 /etc/init.d/boot.local root@233p5:/ > ls -al /etc/rc.d/boot.local -rwxr--r-- 1 root root 447 Jan 30 16:37 /etc/rc.d/boot.local | |____________________ | and found that both had the number 1 where I expected 2. I then went back to an old UNIX manual and did some more reading :-) and tried root@233p5:/ > ls -il /etc/init.d/boot.local 274722 -rwxr--r-- 1 root root 447 Jan 30 16:37 /etc/init.d/boot.local root@233p5:/ > ls -il /etc/rc.d/boot.local 274722 -rwxr--r-- 1 root root 447 Jan 30 16:37 /etc/rc.d/boot.local and, miracles still happen, got the same inodes for both files. So it looks like we have a hard link. However, we still have 1 and not 2 :-) I notice you have the same "disease" I then wondered whether SuSE was doing something odd. I therefore went to /tmp and, as root, created two subdirectories z1 and z2. I then cat'd /etc/fstab to z1/test1 to create a file. I finally created a hard link from z2/test1 to z1/test1. When I now did a ls -il on those two test1 files, there were 2's where they should be! At this point, Chuck suggested I do a forced fsck. I had some trouble at first (until he showed me I had to remount / ro; I had tried the SuSE rescue system but it complained about bad superblocks and/or odd "magic numbers". This happened on three boxes so I was unconvinced there was a screwed up file system on all three machines). I have just now finished that fsck -f /dev/hda7 on my notebook and all it reports is 0.2% non-contiguous --- as I suspected from the problem on three boxes (or 4, if we include yours) no screwed up file system. So the mystery now is why do we both get 1 for those linked files. doug filesystem.

Feb. 16, 2002

Re: [Wlug] Newbie Answer.

by Frank Sweetser

On Sat, Feb 16, 2002 at 12:02:40PM -0500, doug waud wrote: > I then went back to an old UNIX manual and did some more reading :-) and > tried > > root@233p5:/ > ls -il /etc/init.d/boot.local > 274722 -rwxr--r-- 1 root root 447 Jan 30 16:37 > /etc/init.d/boot.local > root@233p5:/ > ls -il /etc/rc.d/boot.local > 274722 -rwxr--r-- 1 root root 447 Jan 30 16:37 > /etc/rc.d/boot.local > > and, miracles still happen, got the same inodes for both files. So it > looks like we have a hard link. However, we still have 1 and not 2 :-) Aha - there's the confusion. There's no problem here - boot.local only has one directory entry (aka hardlink) pointing to it. /etc/init.d/ is a directory which contains a directory entry that maps the name boot.local to inum 274722. /etc/rc.d/ is *not* a directory, but rather a symlink. symlinks do not contain any information about that to which they point except the name, so it has no idea if it's pointing to a file, directory, dev entry, etc. So, when /etc/rc.d/foobar is opened, the symlink is hit and replaced with the contents of it's target -> /etc/init.d/foobar, and the entry foobar is looked up in the directory /etc/init.d/ Make sense? -- Frank Sweetser fs at wpi.edu, fs at suave.net | $ x 16 Full-time WPI Network Tech, Part time Linux/Perl guy | Tactical? TACTICAL!?!? Hey, buddy, we went from kilotons to megatons several minutes ago. We don't need no stinkin' tactical nukes. (By the way, do you have change for 10 million people?) --lwall

Feb. 16, 2002