I want to study linux network but I have not a network

On Tue, 02 Nov 2004 19:06:40 +0800, Chen Bin wrote:
> HI,
>
> I am using debian 3.0 as my linux PC and I want to study the linux
> network administartion. When I only have one pc, is it possible for me
> to study it on this only one PC?
>
> Is any emulation that can be done to construct a virtual network within
> my PC?

You can use Vmware (www.vmware.com), but it's quite expensive. The
workstation edition costs $189. But you can get a 30 day fully
functioning trial version.

--
Rolf Arne Schulze
Trans-atlantic weightloss challenge: http://tawlc.net/
Personal weblog: http://roffe.ronningveien.net/

HI,

I am using debian 3.0 as my linux PC and I want to study the linux
network administartion. When I only have one pc, is it possible for me
to study it on this only one PC?

Is any emulation that can be done to construct a virtual network within
my PC?

Any help appreciated!

Chen

In comp.os.linux.networking Chen Bin <(E-Mail Removed)>:
> HI,

> I am using debian 3.0 as my linux PC and I want to study the linux
> network administartion. When I only have one pc, is it possible for me
> to study it on this only one PC?

> Is any emulation that can be done to construct a virtual network within
> my PC?

You can do almost anything just over loop-back, like "ssh
localhost" no need for any emulation, you already have one.

--
Michael Heiming (X-PGP-Sig > GPG-Key ID: EDD27B94)
mail: echo (E-Mail Removed) | perl -pe 'y/a-z/n-za-m/'
#bofh excuse 349: Stray Alpha Particles from memory packaging
caused Hard Memory Error on Server.

Chen Bin wrote:

> I am using debian 3.0 as my linux PC and I want to study the linux
> network administartion. When I only have one pc, is it possible for me
> to study it on this only one PC?
>
> Is any emulation that can be done to construct a virtual network within
> my PC?

Here's a possibility: get a second PCI NIC card, and plug it
into your PC (if you don't already have one, get two).
Give it an IP address. Your PC now has two physical network
interfaces. connect them with a crossover cable, and bang,
you've got a real, physical network.

In a lot of places, PCI NIC cards are really cheap...I don't know
about .cn, though. :-)

Duke

Chen Bin <(E-Mail Removed)> writes:

> I am using debian 3.0 as my linux PC and I want to study the linux
> network administartion. When I only have one pc, is it possible for
> me to study it on this only one PC?
>
> Is any emulation that can be done to construct a virtual network
> within my PC?

If you want a virtual network, you might want to check out User-Mode
Linux. It lets you run several instances of linux kernel on one
system, each with its own network interfaces and the ability to talk
to each other.

http://user-mode-linux.sourceforge.net/

Regards,
--
* Michal Wojciechowski
* odyniec -at- odyniec -dot- net
* http://odyniec.net/
* Signatures longer than three lines suck.

On Tue, 02 Nov 2004 13:56:09 -0500, Duke Robillard wrote:

> Chen Bin wrote:
>
>> I am using debian 3.0 as my linux PC and I want to study the linux
>> network administartion. When I only have one pc, is it possible for me
>> to study it on this only one PC?
>>
>> Is any emulation that can be done to construct a virtual network within
>> my PC?
>
> Here's a possibility: get a second PCI NIC card, and plug it into your PC
> (if you don't already have one, get two). Give it an IP address. Your PC
> now has two physical network interfaces. connect them with a crossover
> cable, and bang, you've got a real, physical network.

Over which no traffic will flow at all, as the kernel is intelligent
enough to recognise local traffic and not send it all the way down the
stack to the hardware layer.

Michal's suggestion of UML is good; alternatively, the OP could scrounge a
486 (laptop if space is tight) and install Slackware or similar. A 10Mb
PCI or PCMCIA NIC can be got very cheaply and is all that is needed for
both installing Slackware and the testing itself.

Regards, Ian

Ian Northeast wrote:
> On Tue, 02 Nov 2004 13:56:09 -0500, Duke Robillard wrote:
>
>>Chen Bin wrote:
>>
>>>I am using debian 3.0 as my linux PC and I want to study the linux
>>>network administartion. When I only have one pc, is it possible for me
>>>to study it on this only one PC?
>>>
>>>Is any emulation that can be done to construct a virtual network within
>>>my PC?
>>
>>Here's a possibility: get a second PCI NIC card, and plug it into your PC
>>(if you don't already have one, get two). Give it an IP address. Your PC
>>now has two physical network interfaces. connect them with a crossover
>>cable, and bang, you've got a real, physical network.
>
> Over which no traffic will flow at all, as the kernel is intelligent
> enough to recognise local traffic and not send it all the way down the
> stack to the hardware layer.

Well, that sucks. :-)

Hmmm...maybe if you added one of those little $50 NAT/"Router" boxes
from Linksys or D-Link or someone, and plugged into that instead of
using a crossover? Seems like that would make the destination non-local.

Duke

Duke Robillard <(E-Mail Removed)> wrote:
>Ian Northeast wrote:
>>Duke Robillard wrote:
>>>Chen Bin wrote:
>>>>I am using debian 3.0 as my linux PC and I want to study the linux
>>>>network administartion. When I only have one pc, is it possible for me
>>>>to study it on this only one PC?
>>>>
>>>>Is any emulation that can be done to construct a virtual network within
>>>>my PC?
>>>
>>>Here's a possibility: get a second PCI NIC card, and plug it into your PC
>>>(if you don't already have one, get two). Give it an IP address. Your PC
>>>now has two physical network interfaces. connect them with a crossover
>>>cable, and bang, you've got a real, physical network.
>>
>> Over which no traffic will flow at all, as the kernel is
>> intelligent
>> enough to recognise local traffic and not send it all the way down the
>> stack to the hardware layer.
>
>Well, that sucks. :-)

Actually that is a *very* good thing.

>Hmmm...maybe if you added one of those little $50 NAT/"Router" boxes
>from Linksys or D-Link or someone, and plugged into that instead of
>using a crossover? Seems like that would make the destination non-local.

Still won't work, because the two interfaces used on the PC are
both known by the kernel. You simply cannot address a packet
*to* a local IP address and have it routed anywhere except the
loopback device.

Which isn't really that much of a problem... There are at least
two ways to emulate a network.

(But first, note that in many areas it might be easy to find an
old PC (anything from an 80386 up to a Pentium I will be
considered virtually useless for anything else). That would
provide a hardware based system to experiment with.)

Absent a hardware solution, the /lo/ device and the /dummy/
device can both be used. With the dummy device several virtual
interfaces can be configured, just as if they were connected to
a physical network. An example:

In /etc/hosts have the following,

192.168.3.1 host0.dummy.com host0
192.168.3.2 host1.dummy.com host1
192.168.3.3 host2.dummy.com host2
192.168.3.4 host3.dummy.com host3

And then configure each as a different interface,

/sbin/ifconfig dummy0 host0 broadcast 192.168.3.255
/sbin/ifconfig dummy0 host1 broadcast 192.168.3.255
/sbin/ifconfig dummy0 host2 broadcast 192.168.3.255
/sbin/ifconfig dummy0 host3 broadcast 192.168.3.255

With the lo device, note that it is configured with a network mask
of 255.0.0.0, which means that *any* IP address in the 127.x.x.x
range will be a loopback. The /etc/host file can assign names
to to 127.0.0.5, 127.0.1.5, and so one. Hence the /etc/hosts
file could have,

127.1.2.1 host0.dummy.com host0
127.1.2.2 host1.dummy.com host1
127.1.2.3 host2.dummy.com host2
127.1.2.4 host3.dummy.com host3

With all of the above, there are essentially two subnets, each
with 4 hosts.

--
FloydL. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) (E-Mail Removed)

On Tue, 02 Nov 2004 22:08:03 +0100, Michal Wojciechowski
<odyniec-(E-Mail Removed)> wrote:

>Chen Bin <(E-Mail Removed)> writes:
>
>> I am using debian 3.0 as my linux PC and I want to study the linux
>> network administartion. When I only have one pc, is it possible for
>> me to study it on this only one PC?
>>
>> Is any emulation that can be done to construct a virtual network
>> within my PC?
>
>If you want a virtual network, you might want to check out User-Mode
>Linux. It lets you run several instances of linux kernel on one
>system, each with its own network interfaces and the ability to talk
>to each other.
>
> http://user-mode-linux.sourceforge.net/
>
>Regards,

You should check out the Adios Project home page
(http://dc.qut.edu.au/adios/), they have a Live-CD distribution that
is geared towards User-Mode Linux as well as offers quite a bit of
information about how they utilize it.

---
Jason DeTiberus

Chen Bin wrote:

> HI,
>
> I am using debian 3.0 as my linux PC and I want to study the linux
> network administartion. When I only have one pc, is it possible for me
> to study it on this only one PC?
>
> Is any emulation that can be done to construct a virtual network within
> my PC?
>
> Any help appreciated!
>
> Chen
Hello Chen,

well UML is certainly an possible option for you. But taking a look in the
Internet, I see plenty of people selling their PII for 30$. Maybe you will
find somebody who will give away an old 486 for a couple of bucks, or maybe
for free. This will definetly make the learning experience faster and
somewhat closer to reality.

With kind regards, Alex