Linux Questions Answered

[Bender10]

And on, and on......

And we would not have it any other way!! Thanks AMDave!!

[jay.perez]

[QUOTE=jay.perez;52051]AMDave,

Was researching info for building an application server and came across this old post from you.

Wondered if you ever got around to the application server project you talked about in your reply below.

If you did and documented it, would love to see what you came up with.

I'm a relative Newbie type but have some hardware and some time so playing around trying different things for the fun and education. Trying to come up with a design for how I should layout a system (using 2 or 3 computers if that's what makes sense) for the following:
Application server
sFTP
Firewall
Gateway
VPN
Remote Desktop
Mail server
Web server
Mixed O/S environment
Shared printers and files on M$ PC

I have successfully installed various distros and gotten the basic desktop setups to work and been able to use SAMBA to connect with my other computers. Heck, I even occasionally get the sound to work and once got my wireless laptop to connect !!!

Just loaded the Feisty Fawn release of Edubuntu which is preconfigured for sharing apps via thin-clients and pretty much works 'out-of-the-box'. Had to figure out how to get the clients to boot off PXE which was a pain on a couple of computers but it seems to be working well for the most part now.

My problem,

I suspect the server is not running some things it should be, such as a firewall program or the VPN software I'd like to mess around with. However, it probably IS running other software that I think could be moved to a different machine which might allow the app server to work better and faster. For example, it's set up as the DHCP server with 2 NICs, etc.

I imagine a future where 1 PC is doing the DHCP serving (or I set up my Linksys router to provide this again), sFTP, and other related network functions, another might be managing user authentication, VPN, Web hosting, mail hosting, etc. The better PC would be dedicated to doing primarily the application serving.

Not sure I have that right or that it's even necessary.

Looking for advice on what hardware to put in place and what functions should be assigned to each piece to optimize the system.

I have the following stuff to work with:
1.6 GHz PC w/ decent graphics card and 750 MEGs of RAM
400 GHz PC with low-end graphics card and 256 MEGs of RAM
Other low-end systems if necessary
16 Port Netgear switch
Cable modem and ISP provider
Wireless-G router with DHCP capability
Time (Work full time but stay up late tinkering)
Limited Linux knowledge
A reasonable amount of patience and determination
An understanding wife
Limited budget for new stuff (She ain't THAT understanding !)

I have not been able to find too much of this high-level design type discussion on the Web and especially have not found any images that shows these configurations in a graphical format. (What I can understand ...)

Thanks in advance for any advice you can offer or point me to.

Jay Perez
Rochester, NY

Vaughan advises that the networking question is surpassed by a useage change for that box. But if anyone else has a repeat of this issue, it would be interesting to go through the above article to see if it is solved.

For the old-hats, I intend to start a new thread shortly on building a Linux application server using the kind of software you would find in a corporate data-centre.

Hi Dave,

Thanks for the excellent explanations and suggestions.

I'm new to the forum and saw your first note the other day but didn't realize the next two were also for my benefit.

I have successfully (mostly) set up my network in two different configurations; In the first one, I had my original home network hooked up to my router which provided the DHCP and firewall functions. The new Edubuntu server was added first as a stand-alone network (not plugged into the Internet or my home network) with the server, a 4 port switch, and a couple of PCs being used as thin-clients. This also worked well.

I then plugged the first NIC into my router which gave the server, and therefore the thin-clients, access to the Internet. (Was confused at first as I thought this was going to cause conflicts with having two DHCP servers on one network. I'm guessing the DHCP on the server is somehow isolated to my second NIC and going out only to the thin-clients ...)

Everything worked perfectly in this configuration except I now had two sub-nets and the limitations this causes. For example, I really want to have it so any computer on my network can be made to either boot up normally off the harddrive but optionally to boot off the network which will cause it to connect to the Edubuntu server and become a thin-client.

Sooo, I redid the wires and did just that, the Edubuntu erver was connected directly to my IPS cable modem on one NIC and to my 16 port switch on the other. The router was taken out of the loop. (It was put back in later with everything turned off except the wireless feature)

This setup really worked well with one huge problem I can't resolve; the non-Edubuntu machines can see everything insdie the house, including the server, but cannot get out to the Internet.

Otherwise, it's really, really Kool being able to boot them up in either O/S. (In fact, I have a couple that were already dual-boot with Linux and M$ and now they have a third option !)

If I could solve that, I could leave the network in that configuration for quite a while as I try to figure out what to do next about splitting up some of the services onto the old 4000 Mhz machine ... ;-)

I prefer to avoid static IPs right now as I'm constantly adding/removing PCs and also have people come over with their laptops and connect to my wireless network.

Thanks again.

Jay

[jay.perez]

Hi Dave,

I sent the note below back last week but think I messed up and did it as a reply to my own posting so you may not have seen it. Not only am I lacking in Linux skills but I ain't so good with the whole forum thing, either ...

Anyway, got to a certain point with my Edubuntu project but ran into a brick wall and not making any progress these days.

Does the forum site allow us to post images ? If so, I have a sketch of one of the configurations I had working that I could share for comments.

Thanks.

Jay

~~~~~~~~~ ORIGINAL NOTE BELOW ~~~~~~~~~~

Thanks for the excellent explanations and suggestions.

I'm new to the forum and saw your first note the other day but didn't realize the next two were also for my benefit.

I have successfully (mostly) set up my network in two different configurations; In the first one, I had my original home network hooked up to my router which provided the DHCP and firewall functions. The new Edubuntu server was added first as a stand-alone network (not plugged into the Internet or my home network) with the server, a 4 port switch, and a couple of PCs being used as thin-clients. This also worked well.

I then plugged the first NIC into my router which gave the server, and therefore the thin-clients, access to the Internet. (Was confused at first as I thought this was going to cause conflicts with having two DHCP servers on one network. I'm guessing the DHCP on the server is somehow isolated to my second NIC and going out only to the thin-clients ...)

Everything worked perfectly in this configuration except I now had two sub-nets and the limitations this causes. For example, I really want to have it so any computer on my network can be made to either boot up normally off the harddrive but optionally to boot off the network which will cause it to connect to the Edubuntu server and become a thin-client.

Sooo, I redid the wires and did just that, the Edubuntu erver was connected directly to my IPS cable modem on one NIC and to my 16 port switch on the other. The router was taken out of the loop. (It was put back in later with everything turned off except the wireless feature)

This setup really worked well with one huge problem I can't resolve; the non-Edubuntu machines can see everything inside the house, including the server, but cannot get out to the Internet.

Otherwise, it's really, really Kool being able to boot them up in either O/S. (In fact, I have a couple that were already dual-boot with Linux and M$ and now they have a third option !)

If I could solve that, I could leave the network in that configuration for quite a while as I try to figure out what to do next about splitting up some of the services onto the old 4000 Mhz machine ... ;-)

I prefer to avoid static IPs right now as I'm constantly adding/removing PCs and also have people come over with their laptops and connect to my wireless network.

Thanks again.

Jay

[AMDave]

Hi Jay.

I guess I missed the question in your last post. My bad.
I don't have sufficient equipment on hand to replicate the problem these days. I have to go on the test that I did about a year ago with 1 server and 1 client. I remember having some similar problems.

I think if your Edubuntu server is the primary machine then you may be able to circumvent the problem by setting up a proxy (eg squid) on that machine and pointing your windows machines to it.

But it would be nice to have them working with the internet whether they were using a proxy or not.

I'll be honest, I have done some reading on this but the slicing and dicing of sub-nets is still somewhat beyond me. I have to admit when I am beat.

The closest I can come is this
https://lists.ubuntu.com/archives/ed...er/001882.html
the trail ran out there.
The gist was that the router should have DHCP turned off and all DHCP should be served by the Edubuntu server
Also there may be something else that needs to be cleaned-up or added in the dhcp.conf file.
Further reading on dhcp.conf started to fold my skull inside out so I have to take a break.

I think you need the knowledge and experience of Chuck on IRC chat at "#ltsp on irc.freenode.net"
The client-server technology you are using originates from LTSP.org
There is more information about their support here:
http://wiki.ltsp.org/twiki/bin/view/...Support_Forums

If your router has DHCP turned off and only the Edubuntu is serving DHCP then I think you need an LTSP expert to look at your dhcp.conf file.

[jay.perez]

Dave,

I joined the IRC chat Friday night and hooked up with hoogbigfoot. He walked me through a variety of settings and ultimately we did it exactly as you have stated in your last note.

I had tried this setup a couple of times before without success.

It turned out the only missing piece that I left out was setting the router's IP address to the same address as the 'gateway' address setting on the server.

Holy crap ! I spent hours on chats and forums chasing that around and it turned out to be extremely simple !!!

Worse than that, I now realize that several people had pointed me in that direction but I didn't understand their suggestions about what needed to be done ...

Oh well, I learned a lot of good stuff anyways and met some very smart and helpful people along the way.

Thanks very much for the info and help and turning me onto the LTSP chat.

Jay

Hi Jay.

https://lists.ubuntu.com/archives/ed...er/001882.html
the trail ran out there.
The gist was that the router should have DHCP turned off and all DHCP should be served by the Edubuntu server
Also there may be something else that needs to be cleaned-up or added in the dhcp.conf file.
Further reading on dhcp.conf started to fold my skull inside out so I have to take a break.

I think you need the knowledge and experience of Chuck on IRC chat at "#ltsp on irc.freenode.net"
The client-server technology you are using originates from LTSP.org
There is more information about their support here:
http://wiki.ltsp.org/twiki/bin/view/...Support_Forums

If your router has DHCP turned off and only the Edubuntu is serving DHCP then I think you need an LTSP expert to look at your dhcp.conf file.

[AMDave]

That is terrific!
Welcome to multi-boot heaven ;-)

As a follow up on the slicing and dicing of sub-nets, my sources have directed me to the "IP Journal". Among their articles there was aparently a well written exposition on subnets, with a follow up article which added further clarification. I am hunting it down.


/ed

Part 1
http://www.cisco.com/web/about/ac123...addresses.html

Part 2 (correction)
http://www.cisco.com/web/about/ac123...rrections.html

The IP Journal cumulative index is found here
http://www.cisco.com/web/about/ac123...umulative.html

ed/

[Bender10]

Hi Dave,

As an aspiring Linux user, I would like to use a recent install (Fedora 7) for surfing the interweb and other fun activities.

My problem for today is not being able to enter 'FlashChat' on my favorite web page...

Whenever I 'click' on the icon to enter the site's Flashchat area, I get sent to the Adobe site to download and install 'Adobe Flash Player' (which I have done and rebooted (a couple of times)). I'm sorta stuck at this point....

signed,
Befuddled in Bundaberg

[AMDave]

The Unofficial Fedora FAQ only gets you part of the way there:
http://www.fedorafaq.org/#flash

This is a common problem as there are so many distributions that install programs to different locations.
The software providers tend to cater for one or two, but at this time there no easy way to cater for all of them.

FOSSwire is maintaining plenty of useful how-to's these days:
http://fosswire.com/2007/11/05/quick...r-on-fedora-7/
(note that there is another "quick" method in a comment under that which is brute force and will usually make it work - hint)

Or from a community based site related to the plugin itself here: http://macromedia.mplug.org/faq.html

1. I installed the RPM package but Flash does not work.

Open a terminal and run /usr/lib/flash-plugin/setup.

If you do not see any error messages, then it probably worked. Be
sure to fully close your web browsers and run it again from scratch
before testing the Flash plugin for the first time.

In any Mozilla compatible browser, open "about:plugins" within the
URL bar and it should show a list of all installed plugins.
You should see "Shockwave Flash" somewhere in that list.

The better way to get this all sorted out would be if the providers of various distributions which where they have installed applications in non-standard locations, would create symbolic links in the right folders that link to the files where the software providers have installed their driver/add-on files.

Some distros are implementing that solution, but some older versions (Like F7) don't have that built in.

If it's still not working after that give me a blast "C'mon, AMDave!" LOL

[Bender10]

Hi Dave,

I figured out my problem (i hope). I am running Fedora 64 bit, and Flash is not supported yeti....

So I had to load Firefox 32 bit....

Signed,
Giddy in Gladstone

[AMDave]

the 64-bit version does explain your issues.

The flash and java plugin problems have been resolved for 64-bit fedora:
http://www.fedorafaq.org/#64bit-browse
or you could do this:
http://www.linuxheadquarters.com/how.../flash64.shtml

I have observed no great advantage to running a 64-bit browser, except for a slightly smaller footprint on the disk.
32-bit FF on the 64-bit OS is indeed more painless, at least until more 64-bit support is actually built into the 64-bit libraries. Improvements in support are coming along slowly, but it is taking longer than expected for s/w providers to recognise the huge increase in shift from 32 to 64-bit desktops. I suppose this may be mainly because so many are still running 32-bit OSs on their 64-bit machines (possibly including the s/w providers themselves!).