LinuxQuestions.org
Visit Jeremy's Blog.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices


Reply
  Search this Thread
Old 10-26-2003, 11:33 PM   #1
toastermaker
Member
 
Registered: Oct 2003
Location: coastal alabama, united states
Distribution: Mandrake 10.0 official, slackware 9.1
Posts: 219

Rep: Reputation: 30
how do I find config info for simple 2 computer lan


I hope to use mandrake control center to set up a simple 2 'puter lan. I dont need to share an internet connection at this time.
I am almost completely ignorant of the command line though I am learning slowly.
I have looked at a hundred post hoping to find link to info I need. Hopefully I have absorbed some info that will help me in the future but for now I still havent found the basic info I need.

The help file in Mandrake tells me to get the basic info I need from my System Administrator. Unfortunately that is me.

The mandrake wizard for a lan connection has "auto config IP" selected by default, and ask for me to supply; Zeroconf hostname, http and ftp proxies.

There is also a "configure lan" button. It asks for me to supply; IP address, netmask, boot protocol and dhcp client.

one computer - mandrake 9.2 eth0- on board sis900
other computer -mandrake 9.2 eth0- on board RTL 8139

What markings on my cat6 cable do I need to look at to make sure its the right cable?

Thanks in advance, any help in finding the info I need will be greatly appreciated.
 
Old 10-27-2003, 12:04 AM   #2
tgflynn
Member
 
Registered: Oct 2003
Location: Rochester, New York (USA)
Distribution: Debian
Posts: 119

Rep: Reputation: 15
First if you're going to connect the 2 computers directly (with know hub or switch) you'll need a crossover cable. I don't know of any standard markings that indicate that a cable is a crossover cable. Most network cables are not crossover cables so your unlikely to find one lying around unless you either bought or made it for that purpose.

Next you need to decide on an IP addressing range and IP addresses for each computer. To simplify things I suggest the following arrangement :

machine A :
address: 192.168.1.1

machine B:
address: 192.168.1.2

common to both machines:
netmask : 255.255.255.0
broadcast address : 192.168.1.255
network address : 192.168.1.0

(you may or may not need the last 2 parameters)

I can't help you much with the graphical Mandrake configuration utilities because I'm not currently running Mandrake. On each machine you will need to turn automatic IP configuration off (this would require a DHCP server which you don't have). You should then be asked for the IP address and the netmask (and possibly the other 2 parameters). You don't need to specify a default gateway because you don't have access to any other network.

Hope this helps.

Tim
 
Old 10-27-2003, 04:30 PM   #3
toastermaker
Member
 
Registered: Oct 2003
Location: coastal alabama, united states
Distribution: Mandrake 10.0 official, slackware 9.1
Posts: 219

Original Poster
Rep: Reputation: 30
Thanks for the responce tgflynn

Still I am pretty much at a loss. Me being an extreme newbie I certainly was afraid to post in any other catagory, but should I ask the moderator or such if I may post original question in Mandrake specific site seeing as I want/need to use Gui config tools as much as possible?
And thanks again.
 
Old 10-27-2003, 05:16 PM   #4
Demonbane
LQ Guru
 
Registered: Aug 2003
Location: Sydney, Australia
Distribution: Gentoo
Posts: 1,796

Rep: Reputation: 47
OK these are quick and dirty instructions:
hook the 2 PCs up with the cable(make sure its a crossover cable)
go to DrakConnect in Mandrake Control Center, turn on expert mode(lol)
Configure LAN
ip address: 192.168.1.1
netmask: 255.255.255.0
boot protocol: static
started on boot: yes
dhcp client: (leave blank)
run to the next PC and do the same but change the ip address to 192.168.1.2
and that's it :-)
to test if its working use "ping <ip address of other pc>"
if you get ping response then you've done it.

Last edited by Demonbane; 10-27-2003 at 07:41 PM.
 
Old 10-27-2003, 07:21 PM   #5
toastermaker
Member
 
Registered: Oct 2003
Location: coastal alabama, united states
Distribution: Mandrake 10.0 official, slackware 9.1
Posts: 219

Original Poster
Rep: Reputation: 30
Thank you so much Demonbane.

By trying to apply the info you provided I think I have taken at least a small step in the right direction.

My ping responce has gone from "the network is not reachable" to "icmp_seq=<n> destination host unreachable"

What responce from a ping would be a "good" responce at this point.

Thanks again
 
Old 10-28-2003, 02:37 AM   #6
Demonbane
LQ Guru
 
Registered: Aug 2003
Location: Sydney, Australia
Distribution: Gentoo
Posts: 1,796

Rep: Reputation: 47
K that either means you made a mistake when entering these ip configurations or that there's a problem with the physical connection, run /sbin/ifconfig to double check the configuration and make sure the leds on the back of the NICs are on.
You should be able to get a ping response when you ping yourself.
 
Old 10-28-2003, 08:03 AM   #7
toastermaker
Member
 
Registered: Oct 2003
Location: coastal alabama, united states
Distribution: Mandrake 10.0 official, slackware 9.1
Posts: 219

Original Poster
Rep: Reputation: 30
Thanks Demonbane

one box

eth0 Link encap:Ethernet HWaddr 00:E0:18:AF:30:AE
inet addr:192.168.1.2 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:532 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:0 (0.0 b) TX bytes:31920 (31.1 Kb)
Interrupt:10 Base address:0xb000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:2758 errors:0 dropped:0 overruns:0 frame:0
TX packets:2758 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:209428 (204.5 Kb) TX bytes:209428 (204.5 Kb)


other box


eth0 Link encap:Ethernet HWaddr 00:0C:6E:3C:87:97
inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:45 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:0 (0.0 b) TX bytes:1890 (1.8 Kb)
Interrupt:3 Base address:0x8800

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:447 errors:0 dropped:0 overruns:0 frame:0
TX packets:447 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:36290 (35.4 Kb) TX bytes:36290 (35.4 Kb)

I hope this is what you want by "ping myself"

PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=0.081
ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=0.066
ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=0.066

And here are some lines when I ping the other box

PING 192.168.1.2 (192.168.1.2) 56(84) bytes of data.
From 192.168.1.1 icmp_seq=1 Destination Host Unreachable
From 192.168.1.1 icmp_seq=2 Destination Host Unreachable

My cards are "on board " and I dont see any leds

When I bought the cable I told the man specifically that I wanted only to connect two computers directly together, similar to what I had done with a parallel cable,win98se and the" direct cable connection" program
He gave me what he said I needed, a cat6 cable, but I dont know for sure if its cross or straight. The packaging is long gone. Do you know of markings I could look for on the cable to identify witch type it is? Its a 50' cable and I dont want to go buy another one if it isnt needed.

Thanks again Demonbane.

Continued graditude to all those who help us newbies

Last edited by toastermaker; 10-28-2003 at 08:16 AM.
 
Old 10-28-2003, 09:01 AM   #8
tgflynn
Member
 
Registered: Oct 2003
Location: Rochester, New York (USA)
Distribution: Debian
Posts: 119

Rep: Reputation: 15
This looks like a routing problem. Could you post the output of the command :

/sbin/route -n

on both boxes.

Tim
 
Old 10-28-2003, 09:06 AM   #9
tgflynn
Member
 
Registered: Oct 2003
Location: Rochester, New York (USA)
Distribution: Debian
Posts: 119

Rep: Reputation: 15
Then again it may be an ARP problem which would lead to suspect the physical connection.

Another thing you can do is use a program called tcpdump. This is an ethernet sniffer which is either installed on your machines or that you may need to install from the Mandrake CD's.

You'll need to run it as root.

Try running the command :

tcpdump

on machine B

and

ping 192.168.1.2

on machine A.

If tcpdump doesn't print anything while the ping is running it means that no packets are getting through across the cable.

Tim
 
Old 10-28-2003, 09:20 AM   #10
tgflynn
Member
 
Registered: Oct 2003
Location: Rochester, New York (USA)
Distribution: Debian
Posts: 119

Rep: Reputation: 15
Oh, if it does turn out that the 50' cable is not a cross-over cable it would probably be cheaper (and perhaps in the long run more useful) to buy a small switch or hub instead of another 50' cable.

Tim
 
Old 10-28-2003, 01:18 PM   #11
toastermaker
Member
 
Registered: Oct 2003
Location: coastal alabama, united states
Distribution: Mandrake 10.0 official, slackware 9.1
Posts: 219

Original Poster
Rep: Reputation: 30
Output from /sbin/route -n from one box :


Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
[teabeartwo@localhost teabeartwo]$

And from the other box :

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
[teabear@localhost teabear]$

tcpdump shows no signs of receiving anything. It just continues to listen on eth0 and prints out nothing while I am pinging from the other box.

Thanks tgflynn

Iam going to google for cable identification.

Continued gratitude to all those who help us newbies.

Last edited by toastermaker; 10-28-2003 at 01:22 PM.
 
Old 10-28-2003, 03:27 PM   #12
tgflynn
Member
 
Registered: Oct 2003
Location: Rochester, New York (USA)
Distribution: Debian
Posts: 119

Rep: Reputation: 15
As far as I can tell your interface configurations and routing tables are correct. I've compared them to mine and everything checks. This would seem to suggest a cable problem.

Except there's one thing I don't understand. That's why you're seeing host unreachable messages when you ping. If I disconnect my cable, which should simulate using a straight-through cable between 2 PC's, I don't get that. I don't see any replies at all.

There is one more thing I suggest you try. Again you're going to use Drake Config for this so I can't help with the details. Try to specify 192.168.1.1 as the GATEWAY parameter for the machine of that address and 192.168.1.2 on the other machine. Once you've done this, do whatever is needed so the changes take effect (rebooting if necessary). Then redo the route -n command. There should now e an additional default root that looks like this in the list :

0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0

Theoretically this shouldn't be necessary and for me the LAN works fine without a default route. But then I'm running a 2.6 kernel and it's conceivable that for some reason your kernel needs this to be happy.

Tim
 
Old 10-28-2003, 03:39 PM   #13
tgflynn
Member
 
Registered: Oct 2003
Location: Rochester, New York (USA)
Distribution: Debian
Posts: 119

Rep: Reputation: 15
Actually you can test this change easily without Drake Config by issuing the following command as root :

route add default gw 192.168.1.1

on one machine and similarily on the other.

The change won't be permanent across reboots though.

Tim
 
Old 10-28-2003, 03:44 PM   #14
toastermaker
Member
 
Registered: Oct 2003
Location: coastal alabama, united states
Distribution: Mandrake 10.0 official, slackware 9.1
Posts: 219

Original Poster
Rep: Reputation: 30
I went out and bought a for sure cross over cable. I will later go wireless if I can but for now wanted to start simple and keep down the cost, while trying to learn something.

Now when I run tcpdump on one box while running ping from the other I get the following ;

PING 192.168.1.23 (192.168.1.23) 56(84) bytes of data.
From 192.168.1.1 icmp_seq=1 Destination Host Unreachable
From 192.168.1.1 icmp_seq=2 Destination Host Unreachable


tcpdump: listening on eth0
14:51:12.902529 arp who-has 192.168.1.23 tell 192.168.1.1
14:51:13.892560 arp who-has 192.168.1.23 tell 192.168.1.1

I hope this is an improvement over what tcpdump was doing before ( just sitting there waiting )

Please advise.

Thanks tgflynn and Demonbane.

Continued gratitude to all those who help us newbies

I didnt see your most recent responces till I went to check this post.
I will use your latest ideas to help troubleshoot unless before then I see where my latest info I posted changes the direction I should go in.

Last edited by toastermaker; 10-28-2003 at 03:53 PM.
 
Old 10-28-2003, 03:45 PM   #15
tgflynn
Member
 
Registered: Oct 2003
Location: Rochester, New York (USA)
Distribution: Debian
Posts: 119

Rep: Reputation: 15
As far as the cable question goes I don't know of any cheap easy way to tell whether its straight-through or crossover.

There are cable testers that will tell you but they're expensive.

You could do it yourself by finding an RJ45-DB9 adaper kit. These have little wires that you can use to map the RJ45 signals to DB-9 signals any way you want. You could use the wires with straps and an ohmeter to find out how it's wired. I wouldn't call this easy though and I don't know if those adapters are easy to find.

Tim
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
how to find the ip address of a computer that is connected to LAN gajaykrishnan Linux - Networking 7 12-03-2010 06:38 AM
Webalizer and collecting LAN info zeky Linux - Networking 2 06-22-2005 02:33 AM
looking for info on early 80's computer kit slackist General 9 07-26-2004 01:19 PM
LAN interface on Gateway stops being able to send info to LAN intermittantly. BurnFEST Debian 2 11-01-2003 04:16 AM
Cannot find gtk-config and glib-config NOT_Skeletor Linux - Software 3 06-27-2003 10:39 AM


All times are GMT -5. The time now is 10:45 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration