View Full Version : Can't connect to network
18th February 2006, 07:05 AM
I'm working with FC4 on a single-boot machine.
I can't reach the network with DHCP (eth0 won't initialize)
I can't assign an IP and get on the network (Destination Host Unreachable)
It's an easy network to connect to from Windows machines. I work on friends and family computers and connecting can be done in my sleep. In the past month or two, I've had 8 or 9 different machines on it (4 are always on).
I've reinstalled FC4 6 or 7 times hoping a new install would work.
I've connected to 3 different routers and my cable modem. I figured surely a fresh install on the cable modem should give me DHCP but it doesn't. I've used a Realtek 8139 NIC card as well as a new gigabit card. The light on my routers light up and the NIC card lights green. I've also tried switching cables. However, my router also ok'ed the cable connections. I've had my router match the IP with the MAC address. And I've tried with and without the firewall.
I've tried everything related on this forum I could find but I cannot get any response from pings. And I cannot ping the FC4 box.
I've put about 30 hours into this and nothing. What am I doing wrong? Or could someone step me through what I should do?
18th February 2006, 02:29 PM
please post the contents of you /etc/sysconfig/network-scripts/ifcfg-eth0 and /etc/resolv.conf files. Do you think that the card ins't being recognized by the kernel?? You can check my doing a dmesg | grep eth0. If there is output, then the card should be initialized and active. That leaves the only problem to settings or cables.
18th February 2006, 03:43 PM
Here are the results:
[root@localhost ~]# dmesg | grep eth0
eth0: Identified chip type is 'RTL8169s/8110s'.
eth0: RTL8169 at 0xe0832000, xx:xx:xx:xx:xx:xx, IRQ 10
r8169: eth0: link up
eth0: no IPv6 routers present
# suggestion from fedoraforum.org
Appreciate you taking the time to look at this.
18th February 2006, 03:56 PM
i assume that (in your /etc/resolv.conf) 192.168.0.1 is your router?? You have to get your DNS servers from your router or your ISP and put it in that file. Not your router. Your router stores DNS server settings, but it isn't the DNS server. If you have a windows box using the same connections - it should already have the DNS server info. Copy that over to the LInux box
replace the x's with the IP's of both your DNS servers. Restart network services (as root) service network restart and you should be able to ping out after that.
18th February 2006, 04:27 PM
Can't find anything on my Win2k machine. On the router device settings, the WAN side has all my ISP settings. My router list DNS as:
I guess that's two IPs with a space between them.
Would I use those in the etc/resolv.conf file? Doesn't seem right because my ISP won't know the IPs for the other computers on my network.
There is also another screen on my router that shows WAN settings. It's set to get a dynamic IP from my ISP. Below that, it shows a Dynamic IP section for my router with the hostname DI-624, the MAC address of the router, and primary and secondary DNS of 0.0.0.0
Would I use that in the etc/resolv.conf file?
19th February 2006, 01:31 AM
You said you connected it to 3 different routers. Can you give us a quick diagram of how your network is setup?
The router the FC4 box is connected to do other pc's connected to it get to the internet? Can you try and ping an external address.
Also try a traceroute to see how far along your network your getting.
The other thing you might want to try that I just thought of, try disabling IPV6
19th February 2006, 06:40 AM
A cable modem connects to cable. From the cable modem is a wireless router (D-Link 624). Several computers link through the wireless network. Several others connect either directly to the D-Link or a switch coming off that router.
I tried clean installs by connecting directly to the cable modem, directly to the D-Link, and directly to a third D-Link router not normally in the network. I've also tried various attempts through the switch.
Regardless of what I've done, I cannot ping an external address. I've also tried disabling IPV6 as well as the firewall.
root@localhost /]# traceroute 192.168.0.1
traceroute to 192.168.0.1 (192.168.0.1), 30 hops max, 38 byte packets
1 localhost (192.168.0.10) 3000.114 ms !H 3000.457 ms !H 3000.336 ms !H
19th February 2006, 11:42 AM
the only other thing I can think of is your NIC's driver isnt working as it should be. I had a few problems installing FC4 on my laptop but after updating the kernel everything worked.
I am running 2.6.15-1 at the moment see if you can download that from another computer and install it and see how you go.
19th February 2006, 09:35 PM
as I said before, your /etc/resolv.conf isn't set properly. You have your gatewar set as your DNS server, that isn't going to work. You have to put your DNS server in your /etc/resolv.conf file - and not your gateway. So once again, I ask, what is you DNS servers? Do you run internal servers? Or do you use your ISP servers? My linksys router shows me the DNS servers it gets from my ISP. If you cable modem is connected to a d-link (i think you said) then find out what the DNS server that this router gets. If you can't get that information from any of your computers/routers, then contact your ISP and ask for the DNS server. Better yet, the ones that I use, are assigned by my ISP, but you should be able to query them. So why not try that....
See if that works for you. If not,t hen you need to find your ISP's DNS servers.
And BTW - don't use IPV6. Most networks (in the US that is) aren't 100% compliant yet. And 9 times out of 10, using or activating IPV6 will slow your system down.
20th February 2006, 05:16 AM
I have IPV6 turned off. I changed resolv.conf and used my ISP nameservers. I get "Destination Host Unreachable" if I ping inside my network and "unknown host" if I ping outside my network.
20th February 2006, 05:53 AM
1222.214.171.124 localhost localhost.localdomain
to your /etc/resolv.conf
Also try going thru "System>Administration>Network" (in Gnome) [Start>System Tools>Network in KDE] to check if your Realtek card is recognized and configured.This is the easiest way to check if your card module is installed into the kernel. note: you will have to provide the / password. I did an install that did not do the loopback setup in resolv.conf and could NOT get into/onto the net.Since your post didn't show a listing for 127.0.0.1, it may be your problem.
If you can ping your cable router (192.168.0.1 I assume) after this, enter the router address into your browser and look for an entry for the "status" of your router. Status is what my Actiontec DSL router actually reads. If you can find this (or similar) page, it should show the DNS nameserver addresses and the search domain.
gedit /etc/resolv.conf should be edited to something similar to
; generated by /sbin/dhclient-script
This doesn't show the lopback interface [I'm in FC5t2] but it is my FC4 /etc/resolv.conf file.
Hope this helps
20th February 2006, 06:11 AM
Appreciate your suggestion, Bill.
However, it did not work. I can also see my card listed. It won't initialize under DHCP (can't get anything from the network) but seems to work fine if I assign the computer an IP. I also see a green light on the NIC card and a light on the router. The router also verifies a cable connection.
20th February 2006, 05:26 PM
one last question, it sounds like your network has several devices attached to it. A modem attached to a wireless hub (what is the IP of this hub??) and then you mentioned that you have your system hooked up to another router (what is the IP of this router?) that was piggy backed off of the wireless hub. You might have a gateway problem. The fundamental principal behind the gateway is that it is the address of the next networking device upstream from your system. So if your wireless router is 192.168.1.1 and your other router is 192.168.1.2 and your computer is connected to that. Then your gateway (theoretically) should be the IP of that second router.
So I would say if you system is still hooked up to that second device, get the IP from that, make it your Gateway, then keep your ISP's DNS servers in the resolv.conf. Test that and see what happens. Also, by chance, do you have firewalls set up?? Try service iptables stop or iptables -L (to list firewall rules) and the iptables --flush to temporarily clear out the rules. It is a possibility you didn't select eth0 as a trusted device, and therefore no packets are leaving your computer.
21st February 2006, 02:30 AM
The IP of the wireless router is 126.96.36.199 Yes, there is a hub connected to that and I have no idea what the IP is. It is assigned by DHCP and only acts to pass traffic between the computers on it and the router. There is no gateway problem with that because those computers have no problem accessing the router which acts as the gateway to the Internet. No computer on the network is aware of the ISP nameservers, either.
Also, my Linux box is attached directly to the wireless router so the other hub would have no influence over its connection.
The Linux box has its firewall turned off. The router's firewall only interacts with traffic from the Internet, not within the network.
eth0 has been listed as a trusted device.
I suspect the problem is that the Linux box is not listening to the network. A driver was installed for the NIC and it shows up in the hardware. Ping says it is broadcasting. But it doesn't receive anything.
21st February 2006, 04:57 AM
I would not be concerned with DNS or resolv.conf, yet. Just use ip addresses, not names. Worry about the names after the network is working.
First, see if the network card is initializing. Run "ifconfig eth0". It should show, among a lot of other good things, that it is "UP".
Then, check your routing table with "route". You should see an entry something like this:
192.168.0.0 * 255.255.255.0 U 0 0 0 eth0
This means that if you ping your router's address, 192.168.0.1, it will get routed out the eth0 port. You should also see a default route that will send all traffic outside of your subnet to the router.
Once you can ping your router, you can then test a ping to an outside address. Lastly, ping an outside name to test your DNS. The DNS addresses should be very easy to come by (e.g. your isp, your router, your other boxes on the network).
3rd March 2006, 07:15 PM
i have a problem like that. i can`t connect to an AP. when i give 'iwlist scan' i get the list of AP's but i don`t know how to connect. sorry for my en. i've learned from tv. thank you!
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