have to keep restarting network

onyangoliech · #1 25th November 2010, 11:14 AM

I installed Fedora 13 in my machine. Was installed properly. I had internet and everything initially. I have a router directly connected with a cable to my lan. After installed everything I "added" my machine to an already existing network with only windows machines. I added my machine to the network with a cable. My problem now is that I can't access internet. However, I can see all other computers in the network, ping, browse in the network, everything. can't ping anything outside the lan, access the Windows mail server or access any internet site. However if I restart the network with "service network restart" I can browse for a few seconds then it goes down and I have to restart again to continue browsing.
These are the configs;
ifconfig:
eth0 Link encap:Ethernet HWaddr 90:E6:BA:51:50:7D
inet addr:192.168.1.128 Bcast:192.168.7.255 Mask:255.255.248.0
inet6 addr: fe80::92e6:baff:fe51:507d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:232627 errors:0 dropped:0 overruns:0 frame:0
TX packets:30017 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:33240608 (31.7 MiB) TX bytes:5696666 (5.4 MiB)
Interrupt:27 Base address:0x2000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:40 errors:0 dropped:0 overruns:0 frame:0
TX packets:40 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:3664 (3.5 KiB) TX bytes:3664 (3.5 KiB)

cat /etc/resolv.conf

nameserver 41.220.238.4
nameserver 192.201.231.167

nslookup www.yahoo.com
^Z
[1]+ Stopped nslookup www.yahoo.com

sudo iptables -nL
Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

Does anybody know any kind on configuration I have to do in my linux box or in my cisco router to make this work?

---------- Post added at 03:14 AM GMT ---------- Previous post was at 02:04 AM GMT ----------

The router IP is 192.168.1.1 and they are on the same subnet with my computer

marko · #2 25th November 2010, 01:15 PM

I suspect the route is not set up right, what does this say:

Quote:

route -n

Given what you've said, your route should probably look like this:

Quote:

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
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth0
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0

onyangoliech · #3 26th November 2010, 08:12 AM

route -n
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
169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth0
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0

David Becker · #4 26th November 2010, 11:53 AM

Quote:

Originally Posted by onyangoliech

route -n
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

Given

inet addr:192.168.1.128 Bcast:192.168.7.255 Mask:255.255.248.0

(one of) the route(s) should be something like:

192.168.0.0 0.0.0.0 255.255.248.0 .....

If your router is using netmask 255.255.255.0 for a 192.168.1.0 network, then one (or both) of the parties is (are) going to miss broadcast packets.

David

onyangoliech · #5 26th November 2010, 12:22 PM

Quote:

Originally Posted by David Becker

Given

inet addr:192.168.1.128 Bcast:192.168.7.255 Mask:255.255.248.0

(one of) the route(s) should be something like:

192.168.0.0 0.0.0.0 255.255.248.0 .....

If your router is using netmask 255.255.255.0 for a 192.168.1.0 network, then one (or both) of the parties is (are) going to miss broadcast packets.

David

The router subnet mask is 255.255.248.0 could this be a reason why I have to refresh the connection every 2 seconds?

David Becker · #6 26th November 2010, 01:00 PM

Quote:

Originally Posted by onyangoliech

The router subnet mask is 255.255.248.0 could this be a reason why I have to refresh the connection every 2 seconds?

That was the other case (case1: router.netmask==255.255.255.0; case2: router.netmask==255.255.248.0).

In both cases, the client using a netmask of 255.255.255.0 for its route is going to lead to anomalies due to disagreement between the client and the router on the broadcast address. If the client wants to send a broadcast (192.168.7.255), then the route tables won't provide an entry along which the broadcast may travel. pings (and most unicast traffic) will/may go through while more elaborate protocols using broadcasts (samba, etc.) will go flakey.

David

jroa1 · #7 26th November 2010, 01:41 PM

Yes, but the OP said he can ping and browse within the network. He does not mention problems with broadcasts.

David Becker · #8 26th November 2010, 01:46 PM

Quote:

Originally Posted by jroa1

Yes, but the OP said he can ping and browse within the network. He does not mention problems with broadcasts.

My car doesn't work and the technician mentioned that my transmission is faulty but he didn't fix it because I hadn't mentioned problems with my transmission.

David

onyangoliech · #9 26th November 2010, 01:48 PM

Quote:

Originally Posted by jroa1

Yes, but the OP said he can ping and browse within the network. He does not mention problems with broadcasts.

That's true I can ping the router interface but I cannot browse. I cannot even telnet to the router and maintain the connection for more that 2 seconds. It's quite strange. I also have a FC 10 server running squid. Now I cannot use the proxy.

jroa1 · #10 26th November 2010, 01:52 PM

I would be mad at my technician if I brought the car in because it would not start and he says, "It sounds like transmission trouble to me".

David Becker · #11 26th November 2010, 01:54 PM

Quote:

Originally Posted by onyangoliech

That's true I can ping the router interface but I cannot browse. I cannot even telnet to the router and maintain the connection for more that 2 seconds. It's quite strange. I also have a FC 10 server running squid. Now I cannot use the proxy.

It's not quite strange considering the settings.

On the client:

Code:

# route del -net 192.168.1.0 netmask 255.255.255.0
# route add -net 192.168.0.0 netmask 255.255.248.0

David

jroa1 · #12 26th November 2010, 01:55 PM

Quote:

Originally Posted by onyangoliech

That's true I can ping the router interface but I cannot browse. I cannot even telnet to the router and maintain the connection for more that 2 seconds. It's quite strange. I also have a FC 10 server running squid. Now I cannot use the proxy.

Have you double checked the router settings? Sounds to me like the router is blocking your internet access.

David Becker · #13 26th November 2010, 02:00 PM

Quote:

Originally Posted by jroa1

Have you double checked the router settings? Sounds to me like the router is blocking your internet access.

You can lead a mule to water but you can't make him drink.

David