Cable Modem-->Linux Box--->5 Win95 PCs

Cable Modem-->Linux Box--->5 Win95 PCs

Post by Charles Cieck » Fri, 13 Jun 1997 04:00:00



I know nothing(for the most part) of Linux. In two weeks I move to an
area w/cable modems. I'll be living w/4 other roomates who each have
PCs. If we get a cable modem I would like to set up a network so that
everyone can access the net 24/7. What I have read in this news group
leads me to belive that Linux is capable of doing just this and more. My
Qusetion(s) is What do I need to do it? Specificly what distribution
should I buy and what HOWTOs or FAQs should I read? Also what type of
system does my linux box have to be to support 5 clients?

Here is my expected configuration:

comcast<--->cable modem<--->Linux box<--->Win95 box
                                       |->Win95 box
                                       |->Win95 box
                                       |->Win95 box
                                       |->Win95 box
I am using ethernet (coax) cable for linux to win95
runs.

 
 
 

Cable Modem-->Linux Box--->5 Win95 PCs

Post by Frank Sweetse » Fri, 13 Jun 1997 04:00:00



> I know nothing(for the most part) of Linux. In two weeks I move to an
> area w/cable modems. I'll be living w/4 other roomates who each have
> PCs. If we get a cable modem I would like to set up a network so that
> everyone can access the net 24/7. What I have read in this news group
> leads me to belive that Linux is capable of doing just this and more. My
> Qusetion(s) is What do I need to do it? Specificly what distribution
> should I buy and what HOWTOs or FAQs should I read? Also what type of
> system does my linux box have to be to support 5 clients?

Look at:
Linux Network Administrators Guide
Net-Howto
IP Masquerading Howto

sunsite.unc.edu/pub/Linux/docs

--
Windows: I can play Doom!               |RedHat Linux 2.0.30 i486
Linux: I can be a file server, be a Web |Because reboots are for upgrades!

twelve terminals AND play Doom!         |for pgp key.        frank sweetser

 
 
 

Cable Modem-->Linux Box--->5 Win95 PCs

Post by BERMING » Fri, 13 Jun 1997 04:00:00




> Windows: I can play Doom!               |RedHat Linux 2.0.30 i486
> Linux: I can be a file server, be a Web |Because reboots are for
upgrades!

> twelve terminals AND play Doom!         |for pgp key.        frank
sweetser

--and compile a Kernel, and download news, and send/receive FAXes, and be a
Web browser, and service Windows 95 machines over the Ethernet, ...

well, my 486DX/100 with 24 MB memory on Slackware 1.2.13 wasn't real happy
with me playing Doom and running TCP/IP applications over the modem at the
same time, but 2.X kernels seem to have got that squared away.

My favorite day was when I was testing 3 different Web browsers (Mosaic,
Netscape, and Lynx) all at the same time while listening to Internet Radio
on RealAudio, and printing Subgenius Foundation material on the printer
from yet another instance of a web browser.

While all this was going on, I was providing a blow-by-blow description of
it to some friends on IRC.

 
 
 

Cable Modem-->Linux Box--->5 Win95 PCs

Post by Jarrod A. Smit » Sat, 14 Jun 1997 04:00:00



> I know nothing(for the most part) of Linux. In two weeks I move to an
> area w/cable modems. I'll be living w/4 other roomates who each have
> PCs. If we get a cable modem I would like to set up a network so that
> everyone can access the net 24/7. What I have read in this news group
> leads me to belive that Linux is capable of doing just this and more. My
> Qusetion(s) is What do I need to do it? Specificly what distribution
> should I buy and what HOWTOs or FAQs should I read? Also what type of
> system does my linux box have to be to support 5 clients?

> Here is my expected configuration:

> comcast<--->cable modem<--->Linux box<--->Win95 box
>                                        |->Win95 box
>                                        |->Win95 box
>                                        |->Win95 box
>                                        |->Win95 box
> I am using ethernet (coax) cable for linux to win95
> runs.

This is coming to you from a Linux cable modem setup.  While I haven't
personally done what you are asking about, I do use my Linux setup as an
http, ftp and telnet client/server and the cable modem is nothing short
of fantastic.  To help you out, though, I can relate to you what I've
seen in the local cable modem NGs.  There I have seen several success
stories from folks doing exactly what you want here in San Diego.

You will need an ethernet hub that supports 5 machines.  I have seen one
at Fry's recently for $20, but you probably will pay more like $50 for a
decent one.  I think you hook it up like:

                                  |->Win95 box
                                  |->Win95 box
 comcast<--->cable modem<--->Hub<--->Linux box
                                  |->Win95 box
                                  |->Win95 box
                                  |->Win95 box

Then you run IP masquerading on the Linux box (this is part of the
kernel now, you just compile it in), give all your Win95 boxes fake IP
addresses (I think), and route all your packets from the Win95 boxes
through the Linux box.  The Linux box then acts as a proxy for each of
the Win95 boxes, stripping off the identity of their requests and
replacing it with it's own.  To the outside world, it all looks like one
machine (the Linux box), but from your LAN, you have internet access in
the downstream direction for all your computers and in the upstream
direction for your Linux machine.  I believe that the only drawback is
that there is extra traffic on your LAN due to the fact that when data
comes back from the internet to the the Linux box, it has no idea who
requested it, so it gets broadcast over the LAN instead of being routed
back to a specific host.  Again, this is all from memory, I haven't done
it myself so don't take it as gospel.  It should point you in the right
direction though.

Where I'm at, you _can_ pay $5/month each for up to 5 additional real IP
addresses and skip the masquerading part, but I think most people with
multiple machines are saving their money and going with the above setup.

Good luck!

--

The Scripps Research Institute
http://www.scripps.edu/~jsmith

 
 
 

Cable Modem-->Linux Box--->5 Win95 PCs

Post by Dave Brow » Sat, 14 Jun 1997 04:00:00



: > comcast<--->cable modem<--->Linux box<--->Win95 box
: >                                        |->Win95 box
: >                                        |->Win95 box
: >                                        |->Win95 box
: >                                        |->Win95 box
: > I am using ethernet (coax) cable for linux to win95
: > runs.

: You will need an ethernet hub that supports 5 machines.  I have seen one
: at Fry's recently for $20, but you probably will pay more like $50 for a
: decent one.  I think you hook it up like:

:                                   |->Win95 box
:                                   |->Win95 box
:  comcast<--->cable modem<--->Hub<--->Linux box
:                                   |->Win95 box
:                                   |->Win95 box
:                                   |->Win95 box
:                                  

Hi.

Just to put my two pennies worth in.  You will not need the Hub.  If you are using Thin Ethernet i.e 10Base-2, then you build a bus-style network; ensuring of course you have a 50ohmn terminator at each end.

Personally speaking I use it here with a Sparc Station 1, a couple of DOS Boxes, and other junk...  Works great, even possible to put an old Amstrad 1512 on the Net.

I would say however, keep an eye on your security from outside sites.  I went around reading everything I could get on Linux Security, plus joined the various security mailing lists.  Basically you are putting a UNIX box on the Internet, therefore be really careful what you run.  For a start turn off RSH/RCP or set the /etc/hosts.equiv and /etc/hosts.allow file correctly.  Personally I replaced them with Secure Shell (www.datafellows.com), this allows me to use a Compresssing, Encrypted protocol, to and from my University.  Also if you are using PostgreSQL, I would block that port off using the ipfwadm.

Like I say this is only my two pennies worth, but when your machine is connected to the Internet 24 hours a day, you learn to worry.

Anyway, thats my bit.

Yours,
Dave.


 
 
 

Cable Modem-->Linux Box--->5 Win95 PCs

Post by Arcadio A. Sincero J » Sat, 14 Jun 1997 04:00:00




Quote:> I know nothing(for the most part) of Linux. In two weeks I move to an
> area w/cable modems. I'll be living w/4 other roomates who each have
> PCs. If we get a cable modem I would like to set up a network so that
> everyone can access the net 24/7. What I have read in this news group
> leads me to belive that Linux is capable of doing just this and more. My
> Qusetion(s) is What do I need to do it? Specificly what distribution
> should I buy and what HOWTOs or FAQs should I read? Also what type of
> system does my linux box have to be to support 5 clients?
> Here is my expected configuration:
> comcast<--->cable modem<--->Linux box<--->Win95 box
>                                       |->Win95 box
>                                       |->Win95 box
>                                       |->Win95 box
>                                       |->Win95 box
> I am using ethernet (coax) cable for linux to win95
> runs.

        Yes ... this is not a problem for Linux.  Look up the stuff on
IP Masquerading.  IP masquerading lets you put entire LANs on the 'net
without having to get new IPs for each node on the network, with the
box doing the IP masquerading (the Linux box in this case) acting as a
gateway.  One disadvantage to this is that you can't run servers behind the
IP masqing box (well you probably can by redirecting ports).  Also,
another disadvantage is that theres a chance that all 'net apps might not
function correctly behind IP masquerading.  For example, IP
masquerading support for Quake has only been recently added to v2.0.30
of the kernel.  But most of the stuff work.  Should be sufficient.

--
==============================================================================
Arcadio A. Sincero Jr.  a.k.a. The Tick -=LpC=-
Computer Science Undergraduate/Linux Enthusiast/Competitive Bodybuilder
www:   http://www.coming.to.a.web.site.near.you.com

Come hang out on IRC with me at irc.linpeople.org.  Or come face me in Quake
at quake.linpeople.org!

 
 
 

Cable Modem-->Linux Box--->5 Win95 PCs

Post by Andrew Jon Lundber » Tue, 17 Jun 1997 04:00:00




> > I know nothing(for the most part) of Linux. In two weeks I move to an
> > area w/cable modems. I'll be living w/4 other roomates who each have
> > PCs. If we get a cable modem I would like to set up a network so that
> > everyone can access the net 24/7. What I have read in this news group
> > leads me to belive that Linux is capable of doing just this and more. My
> > Qusetion(s) is What do I need to do it? Specificly what distribution
> > should I buy and what HOWTOs or FAQs should I read? Also what type of
> > system does my linux box have to be to support 5 clients?

> > Here is my expected configuration:

> > comcast<--->cable modem<--->Linux box<--->Win95 box
> >                                        |->Win95 box
> >                                        |->Win95 box
> >                                        |->Win95 box
> >                                        |->Win95 box
> > I am using ethernet (coax) cable for linux to win95
> > runs.

> This is coming to you from a Linux cable modem setup.  While I haven't
> personally done what you are asking about, I do use my Linux setup as an
> http, ftp and telnet client/server and the cable modem is nothing short
> of fantastic.  To help you out, though, I can relate to you what I've
> seen in the local cable modem NGs.  There I have seen several success
> stories from folks doing exactly what you want here in San Diego.

> You will need an ethernet hub that supports 5 machines.  I have seen one
> at Fry's recently for $20, but you probably will pay more like $50 for a
> decent one.  I think you hook it up like:

>                                   |->Win95 box
>                                   |->Win95 box
>  comcast<--->cable modem<--->Hub<--->Linux box
>                                   |->Win95 box
>                                   |->Win95 box
>                                   |->Win95 box

> Then you run IP masquerading on the Linux box (this is part of the
> kernel now, you just compile it in), give all your Win95 boxes fake IP
> addresses (I think), and route all your packets from the Win95 boxes
> through the Linux box.  The Linux box then acts as a proxy for each of
> the Win95 boxes, stripping off the identity of their requests and
> replacing it with it's own.  To the outside world, it all looks like one
> machine (the Linux box), but from your LAN, you have internet access in
> the downstream direction for all your computers and in the upstream
> direction for your Linux machine.  I believe that the only drawback is
> that there is extra traffic on your LAN due to the fact that when data
> comes back from the internet to the the Linux box, it has no idea who
> requested it, so it gets broadcast over the LAN instead of being routed
> back to a specific host.  Again, this is all from memory, I haven't done
> it myself so don't take it as gospel.  It should point you in the right
> direction though.

> Where I'm at, you _can_ pay $5/month each for up to 5 additional real IP
> addresses and skip the masquerading part, but I think most people with
> multiple machines are saving their money and going with the above setup.

> Good luck!

> --

> The Scripps Research Institute
> http://www.scripps.edu/~jsmith

My cable company doesn't offer multiple IPs to cable modem customers.
They only suggest additional cable modems.

I do have a Linux 2.0.30 box serving as a masquerading firewall for a
Windows 95 machine. I have a 3C509 ethernet card connected to the cable
modem by 10baseT cable, and old 3C503 thinnet cards in each machine on my
local network.

IP forwarding and masquerading is built into Linux 2.0.30, so you'll want
that version of linux or later.

There are limits on IP masquerading. I've got ping and such working, but
not normal ftp. Passive FTP, as used in netcape works fine. TCPIP
connections work best, as there are return ports that can be properly
used to forward the masquerading packets. So, telnet, www, and other
tcpip actions work fine. Odd things like Diablo don't work. There's no
way for machines out there on the internet to connect to your masqueraded
machines. They can really only respond.

Though I have limited need, I'd probably say that paying $5 a month for
more IPs would be worthwhile (but I doubt many places offer that).

I may be incorrect about some of this even though I'm actually using it
:) Any corrections would be gladly noted, especially if it will improve
my masquerading connectivity.

Andrew

 
 
 

Cable Modem-->Linux Box--->5 Win95 PCs

Post by The Li family » Mon, 23 Jun 1997 04:00:00




Quote:

>There are limits on IP masquerading. I've got ping and such working, but
>not normal ftp. Passive FTP, as used in netcape works fine. TCPIP
>connections work best, as there are return ports that can be properly
>used to forward the masquerading packets. So, telnet, www, and other
>tcpip actions work fine. Odd things like Diablo don't work. There's no
>way for machines out there on the internet to connect to your masqueraded
>machines. They can really only respond.

Are you sure you've got masquerading set up properly? I've got about the
same set up in two places; normal ftp works unless the other server is
not bound to a privileged port (but I know it's my configuration problem;
my firewalling rules are not correct -- some day I'll have to fix that).

If someone really have to connect to a masqueraded machine I guess you'll
need a proxy server then...

 
 
 

Cable Modem-->Linux Box--->5 Win95 PCs

Post by Paul Russel » Thu, 26 Jun 1997 04:00:00



Quote:> IP forwarding and masquerading is built into Linux 2.0.30, so you'll want
> that version of linux or later.

Well, I think any 2.0.x has those.  Certainly 2.0.29 has.  2.0.30 has
protection from SYN flooding though, which is a possible plus if you
accept incoming connections.

Quote:> There are limits on IP masquerading. I've got ping and such working, but
> not normal ftp. Passive FTP, as used in netcape works fine. TCPIP

"insmod ip_masq_ftp" (IIRC).

I always needed to explicitly insmod the ftp-masquerading module for
it to work.

Quote:> tcpip actions work fine. Odd things like Diablo don't work. There's no
> way for machines out there on the internet to connect to your masqueraded
> machines. They can really only respond.

Actually, there is (in a limited way).  You can use a standard port
redirector (such as the one found in fwtk) to direct connections which
go to your masquerading machine to a machine on the inside.

This can be quite useful (eg. for an internal web server).

The security implications of letting connections in are left as a an
exercise for the hacker.

Hope that helps,
Rusty.
--
.sig lost in the mail

 
 
 

1. How to : Win95 PC -- > (via Linux box) --> login to WinNT server

using RedHat 6.0

CONFIGURATION
want to use the box as a router. want the followings:

Subnet A <---> linux box router <---> Subnet B

LAN subnet A want to talk to subnet B via the linux box router. In fact,
Windows 95 workstations in subnet A want to login to Windows NT in subnet B.

CURRENT STATUS
Finally able to get Windows 95 PC (subnet A) to ping to Windows NT server
(subnet B) via the router.

i ) But not the other way round, i.e. Windows NT server (subnet B) CANNOT
ping to Windows 95 PC (subnet A)

PROBLEM
ii ) the Win95 PC still not able to connect NT server : (. Is it the first
thing I have to solve issue i) first?

Do I need to go further to be involved in SAMBA (however what I just want is
that the Win95PC be able to login to WinNT server for now) ?

Thanks

2. rcs or cvs

3. Extremely slow win95->ethernet->linux->(modem PPP) connection.

4. Documentation for /proc filesystem support for a driver?

5. cable modem -> freebsd (natd) -> win95 (problems)

6. HowTo: Program?? for MAC Base64 to -> binary..??

7. cable modem -> freebsd (natd) -> win95 problems

8. class project

9. Win98 --> linux box --> modem --> internet

10. Samba problem: WinXP <-> ADSL <-> Internet <-> Cable <-> Linux

11. Win95/IPX -> IP ->PPP ->Linux ->Novell 3.12

12. Windows95 box -> Linux Box (Static IP) -> Intranet -> Internet?

13. Cable Modem --> Router --> Hub --> Computer w/RHL 7.0