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Old 07-17-2005, 02:33 PM   #1
rmcastil
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DHCP not able to resolve host


I'm running slackware 10.1 (my first distro, I tried redhat but never really did anything with it) and have questions about the way I've setup my Network. I'm running it off an old Dell Dimension 2100 and had to install a Netgear FA311 ethernet card. Through some research I found that I had to use the "natsemi" module to get the card working. Which worked out fine but when I tried using DHCP for my network I was getting some kind of unable to resolve host when I was pinging websites or IPs of computers in my network and lsmod was showing that the natsemi module was "unused". So I went in and setup a static connection which works fine but I still have a couple of questions.

1) Why can't I ping computers that are connected to my router (WRT54G) through a wireless connection ?

2) Since my router is configured for DHCP and I set up a static connection on my linux box, is my connection going to "drop" when the IP lease is up?

Any information would be greatly appreciated by a linux newb like myself.
 
Old 07-17-2005, 03:04 PM   #2
linuxLuser
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Re: DHCP not able to resolve host

Quote:
Originally posted by rmcastil
1) Why can't I ping computers that are connected to my router (WRT54G) through a wireless connection ?
Because it's down. What you need to do with your Linux box is check the info given by the command
Code:
# ifconfig
This will show you what network interfaces (aka NICs) you currently have up and running. That info will be more helpful in determining your problem, because it sounds like your interface just isn't up. It'll be called "eth0". If it's not listed, try
Code:
# ifconfig eth0 up
then
Code:
# ifconfig
again and see if it's listed.
To configure your network cards, use something like "netconfig" or something.

Sorry if you already know all of this.

Quote:
Originally posted by rmcastil
2) Since my router is configured for DHCP and I set up a static connection on my linux box, is my connection going to "drop" when the IP lease is up?
I don't understand why you'd have a lease if you're using a static IP. When the DHCP lease is up, it is renewed automagically. When it's renewed you generally get an IP address, so you'll still have a connection. But since you're depending on the IP of your Linux box being static, whatever service you're running on it that depends on a static IP might not work. Again, I don't know why you'd even have a lease without using DHCP (aka with using a static IP).

I'm sorry I couldn't help much. I probably don't understand your exact problem.

-- the dudEMaN
 
Old 07-17-2005, 06:57 PM   #3
rmcastil
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dudeMan (hope this is what you go by) thanks for your response.

I probably am not explaining it right since I'm new to linux. Plus I'm not much of a network guy so that could be causing additional confusion.

I get my NICs up and running using the module. But when I go into netconfig and setup using dhcp I can't ping anything. So based off the way I setup my router I knew that each of my IPs that were assigned through dhcp starting at 192.168.1.100

Since setting up the network using DHCP didn't work in netconfig I went through the static route and just assigned the IP 192.168.1.110 since I knew that at the most I usually have 5 machines connected (wireless and hard) through that router. I guess my question should be is since the the router distributes IPs using DHCP and what do I do to fix DHCP on the linux box or what do I do to make the router work with a static IP?

And as for my original first question, at this point I have the network up and running, its kind of bootstrapped but working. I can ping computers hardwired to the router and I can ping websites but I can't ping computers connected to the network wirelessly. Is there any reason why for this?
 
Old 07-17-2005, 07:49 PM   #4
rmcastil
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Just a brief update. I found out that I could use an IP just as long as it is out of the range of the DHCP. So in my case the DHCP assigned IPs start at 192.168.1.100 so I just configured my IP on the linux box to be 192.168.1.2

I'm still having problems of pinging computers that are connected to my network through wireless. I get 100% packet loss.
 
Old 07-18-2005, 10:59 AM   #5
linuxLuser
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Hmm...

Well, I'd say try pinging a wired comp from a wireless comp. Then ping a wireless comp from a wired comp. Maybe you have NAT enable on the WRT54G router?

I don't know what to say other than that. My guess is that maybe the wireless computers can ping the wired computers, but not visa-versa.

I have the same wireless router only I don't currently have access to it, otherwise I'd maybe tell you what to do in a little more detail.

--the dudemaN

PS you can call me Dave if you wi$h
 
Old 07-18-2005, 08:29 PM   #6
rmcastil
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Dave,

Yeah I tried pinging to and from each of my machines. The only time a ping gets dropped is from the wired linux box to a wireless laptop. I have WEP encryption enabled but I don't think that makes a difference. Also NAT is disabled on my router. I tried to go in the router and disable the block WAN request but the ping was still dropped. Its not like I'm getting a ping error just a drop so there is 100% packet loss.

Overall I've achieved my goal of getting it working on the network with the small exception of pinging to wireless. I think I'm just going to continue to move forward and learn as much about linux as possible. Thanks for the advice.
 
Old 07-19-2005, 05:18 PM   #7
rkettle
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if you have wlan and lan with wifi and cables... then you essentially have 2 networks with 2 dhcp servers. So there will be problems... better off switching off the dhcp from the router and letting the box give it out. Run nat etc and dhcp from Linux.

Regards
Richard
 
Old 07-20-2005, 12:42 PM   #8
rmcastil
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Richard,

I think I'm not understanding what you are saying. I only have one router (WRT54G) and two computers wired to it, the linux box and the family's windows machine. I have two additional computers connected to the router via wireless, my personal windows machine and a laptop. So I believe they are actually all on the same LAN unless I'm misunderstanding something about networking (whcih definitely could be the case).

I may have two DHCP servers in the sense that my ISP assigns my IP via DHCP and my router assigns the additional computers IPs via DHCP but I don't think this is the cause of the problem, again I could be wrong.
 
Old 08-10-2005, 06:31 AM   #9
cport80
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Hi Ryan.

I think you probably have a few different issues going on.

First of all your router works as a DHCP server. You should be able to set up any network card to use DHCP and get an address directly from the router. You can check this is working from the command line by using ipconfig /all (windows) or ifconfig -a (linux). If the card shows an ip beginning with 192.168 then this is probably working ok. Check on each machine. If your linux box doesn't have a 192.168 address it means you need to turn on the DHCP CLIENT using the dhcpcd adapter command where adapter could be eth0 or might be different if there's a wifi card in there.

Second, all these machines connect to the outside world via your router. This will convert the 192.168 IP's into the IP number your ISP provides for you. For this to work you will need the network address translation (NAT) turned on in your router.

Third, you need some sort of local name resolution. For instance if you ping Lappy then somehow Lappy should be resolved as 192.168.1.X . If your machines are using DHCP then the router should take care of this. If not you need to tell the other machines how to find Lappy. This means putting it's IP address into a hosts file (see c:\windows\system32\drivers\etc\hosts or for slack 10.1 see /etc/hosts)

Fourth - Turn off your wep. Wep isn't very good anyway and should be left off until everything else is working. You can turn it on again later.


You might find these sites useful
http://www.oblogs.blogspot.com/ (see project week entry)
http://atmelwlandriver.sourceforge.net/howto/howto.html (see configuring the driver - it will be similar)

Hope this helps,

Chris
 
  


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