strange dhcp doesn't work

[JudgeJosephDredd]

sorry for sloppy explanation. I just want to make my dhcpd give out ip to my winxp/10.04 computer. then i could set up dns on my server connect my server to internet and use my only internet connection on 2 computers like so [winxp/10.04 comp]---<cable>---[my dhcpd+dns server]---<cable>---[provider]--... and smth more.
so my tests:
[winxp/10.04 comp]---<cable>---[my dhcpd server] no connection
[win7 comp]---<cable>---[my dhcpd server] connection established
[vista comp]---<cable>---[my dhcpd server] connection established
what i fanally want:
[winxp/10.04 comp]---<cable>---[my dhcpd+dns server]---<cable>---[provider]--...

[JudgeJosephDredd]

after editing net files i do # networking restart
after editing dhcpd files i restart dhcpd as #
to connect under 10.04 i do # dhclient

[ptkobe]

Well, back in my days , you couldn't make any of those connections with a common ethernet cable, none of those will work, and no ip will be given. You could do that only if you use a special cable, called a crossover cable. The exterior is pretty much like the normal cables, and I search for the following page to show it to you:
Ethernet crossover cable - Wikipedia, the free encyclopedia

Then I read the first paragraph and I discover there's a modern Auto-MDIX capability. Under a few conditions, "as long as it [Auto-MDIX] is enabled on either end of a link, either type of cable can be used".

Reading the auto-MDIX page (Medium dependent interface - Wikipedia, the free encyclopedia) it says "When two auto-MDIX ports are connected together, which is normal for modern products, the algorithm resolution time is typically < 500 ms". up to half a second to determine the type of cable.

I don't know if "enabled on either end of a link" depends on hardware or OS, either way, it is possible that two of your machines ([win7 comp] and [vista comp]) can detect and establish the connection and the [winxp/10.04 comp] can't.

What can you do/try, then?

First, a bit of language is necessary
by a wall plug, I mean this: http://www.homewired.com.au/componen...5e72fa732d.jpg

A hub is something like this: Ethernet hub - Wikipedia, the free encyclopedia. Is not that you have, is it?

A switch and a router are more evolved but similar in aspect with an hub (you may follow the links to find more).

To verify if your problem is about cables/lack of auto-MDIX, you can
1. buy a crossover cable and try to connect with it.
2. buy a hub or a switch and connect all the computers through it.

Last but not least, if you only have 1 or 2 computers on your LAN (plus the server) you don't need a dhcp/dns server, just give them static ip and edit /etc/hosts file. Unless of course its for learning purposes.
With your solution, after dhcp and dns, you'll have a bit of work ahead to be able to share the internet with your client machine. And that's singular, one client, can't see how you will connect more than one to the server only with cables (another NIC?). My advise will be buy a switch. Or a router.

Hoping this post will be more helpful, regards
Luis

EDIT: Read auto-MDIX is mandatory for Gb and higher data rates. Could you have Gb NIC on the 2 machines working and a 10/100 NIC on the ubuntu machine?

[JudgeJosephDredd]

1.Sorry i meant wall plug
2. i wasn't able to establish point to point. There are good reasons to have dhcpd for me.
thx for your help! I'll consider the cable issue
Is there a simpler way to establish internet sharing through a computer with dhcp?

[ptkobe]

Is there a simpler way to establish internet sharing through a computer with dhcp?

Sorry to insist, yes, with a router. You get hardware DHCP, NAT, Port forwarding and Firewall, and DNS.

The last router i bought, a few weeks ago (with wireless, could find one without), cost me 30€.

You need to have a net infrastruture. It must work with static IPs. Then you can do whatever else you want.

[JudgeJosephDredd]

Thank You very much for your help
Problem solved. It really was the crossover cable thing that you have written about!
Thank you again))
(i have borrowed a crossover cable and it worked fine . the auto crossover worked only for computers moder enough. that explains strange effect)

[JudgeJosephDredd]

Now I want my dhcp server to provide internet connection. Could you give me an advice on what to read about this and how to do it

[ptkobe]

Let me emphasize this. dhcp has nothing to do with internet connection. dhcp will give your LOCAL machines ip's. You may make dhcp to work with a dns to assign names to those ip's and thus resolve them. Nothing to do with internet sharing.

If you really don't want to connect to the internet through a router, I think you may provide internet connection through a computer (running or not the dhcpd), with more than one NIC, with firewall rules. You'll probably need also NAT/masquerading.

Bottom line, first define your real/projected local net infrastructure (physical), rethink your question, close this solved topic and open a new one with the new question. That's what I believe will be the correct way to do it.

Best regards
Luis

[JudgeJosephDredd]

Let me emphasize this. dhcp has nothing to do with internet connection. dhcp will give your LOCAL machines ip's. You may make dhcp to work with a dns to assign names to those ip's and thus resolve them. Nothing to do with internet sharing.

Thank you. I know That . Thank you for solving my problem. i don' know how to close the thread so:
SOLVED.closed