I've got an IP but can't get internet to work!

tentolga · 08-28-2004, 10:59 AM

My linux box is able to get an IP from DCHP server but I'm not able to connect the internet. What would be the problem?

nvargas · 08-28-2004, 11:08 AM

Please run ifconfig as root and paste the output here.

tentolga · 08-28-2004, 11:29 AM

ok, here it is...

Code:

eth0      Link encap:Ethernet  HWaddr 00:0B:06:2C:8E:D1
          inet addr:194.54.xxx.xxx  Bcast:194.54.xxx.255  Mask:255.255.252.0
          inet6 addr: fe80::20b:6ff:fe2c:8ed1/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:880 errors:0 dropped:0 overruns:0 frame:0
          TX packets:30 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:42132 (41.1 Kb)  TX bytes:2841 (2.7 Kb)

eth1      Link encap:Ethernet  HWaddr 00:DD:10:00:8C:1C
          inet addr:192.168.0.1  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::2dd:10ff:fe00:8c1c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:103 errors:0 dropped:0 overruns:0 frame:0
          TX packets:99 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:10018 (9.7 Kb)  TX bytes:12189 (11.9 Kb)
          Interrupt:9 Base address:0xd800

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:1899 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1899 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:2041632 (1.9 Mb)  TX bytes:2041632 (1.9 Mb)

tentolga · 08-28-2004, 11:50 AM

Help please... It's really important for me...any idea? what would be the problem?

tentolga · 08-28-2004, 12:33 PM

anybody there?

I'm sitting here and waiting for an answer...going crazy..All I need a little help.

cruddybuddy · 08-28-2004, 12:58 PM

Don't count on it. I waited for days to get an answer to my question and still nothing. Just stick with Windows and you'll be fine.

Netizen · 08-28-2004, 04:11 PM

Quote:

Originally posted by cruddybuddy
Don't count on it. I waited for days to get an answer to my question and still nothing. Just stick with Windows and you'll be fine.

Did you try to find help on your own or did you give up because no one would do it for you?

tentolga:

Is this your main PC or is this a router? Why do you have 2 nics?

Netizen

Poetics · 08-28-2004, 04:13 PM

And on eth0 your subnet is 255.255.252.0 --- is this what you set it up to use?

cruddybuddy · 08-28-2004, 05:30 PM

Quote:

Originally posted by Netizen
Did you try to find help on your own or did you give up because no one would do it for you?
Netizen

Nope, I've been trying for hours on end, everyday since I first posted my question. Someone did finally post a reply for me. *squeak squeak*

arno · 08-28-2004, 06:09 PM

can you
a)
ping -c 3 66.102.9.104
b)
ping -c 3 www.google.com

if a= no
Post the content of
route -n

then
if b=no
Post the content of
cat /etc/resolve.conf

tentolga · 08-29-2004, 01:22 AM

This is the firewall script which I created via a script generator. One of linux fellows from here helped me in order to add required lines.

Code:

#!/bin/sh

#iptables script generator: V0.1-2002
# Comes with no warranty!
# e-mail: michael@1go.dk

# Diable forwarding
echo 0 > /proc/sys/net/ipv4/ip_forward

LAN_IP_NET='192.168.0.0/24'
LAN_NIC='eth1'
WAN_IP='194.54.xxx.xxx'
WAN_NIC='eth0'

# load some modules (if needed)
modprobe ip_conntrack_ftp ## passive ftp modules
modprobe ip_nat_ftp

# Flush
iptables -t nat -F POSTROUTING
iptables -t nat -F PREROUTING
iptables -t nat -F OUTPUT
iptables -F

iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT

# enable Masquerade and forwarding
iptables -t nat -A POSTROUTING -s $LAN_IP_NET -j MASQUERADE
iptables -A FORWARD -j ACCEPT -i $LAN_NIC -s $LAN_IP_NET
iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT

# STATE RELATED for router
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
##
iptables -A INPUT -s $LAN_IP_NET -j ACCEPT

##
iptables -A INPUT -s 127.0.0.1 -j ACCEPT
iptables -A INPUT -d 127.0.0.1 -j ACCEPT

# Enable forwarding
echo 1 > /proc/sys/net/ipv4/ip_forward

And this is the output of ping -c 3 www.google.com

Code:

PING 216.239.59.99 (216.239.59.99) 56(84) bytes of data.
From 194.54.xxx.xxx icmp_seq=0 Destination Host Unreachable
From 194.54.xxx.xxx icmp_seq=1 Destination Host Unreachable
From 194.54.xxx.xxx icmp_seq=2 Destination Host Unreachable

This my resolv.conf file.

Code:

; generated by /sbin/dhclient-script
nameserver 212.175.13.34
nameserver 212.175.13.35
nameserver 212.156.4.10

and the last one kernel IP routing table

Code:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.0.0     0.0.0.0         255.255.255.0   U     0      0        0 eth1
194.54.32.0     0.0.0.0         255.255.252.0   U     0      0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     0      0        0 eth1
0.0.0.0         194.54.32.1     0.0.0.0         UG    0      0        0 eth0

When I was trying to get these outputs something strange happened.
I don't know why but suddenly I was able to open google..but it was very slow...very very slow..then I lost the connection again, actually not connection just web...

If there is anything else that you would like to see, let me know...

arno · 08-29-2004, 10:22 AM

Your network configuration is OK, there are no errors on your eth0, I lack the experience to give an opinion in reference to iptables.

Could you get hold of a live cd like knoppix so you could exclude the firewall settings.

What are you using to get an Internet connection ?
I read you called it an dhcp server !

tentolga · 08-30-2004, 01:28 AM

I'm using FC2 and have a cable modem which is connectted via USB to my computer. There is a program called dhclient, the linux box is using this program to get an IP from DHCP server. When I looked into the logs I saw an error like;

dhclient :sit0 :unknown hardware address type 776

I think all this stuff messed up my cable modem (Motorola SB4200) . I don't know why but I'm waiting too long to get the modem to be online. I mean it takes too much time to see the orange activity light blinking. I tried to monitor what was going on the network and got some results. All the packages around the network were ARP packages. Before all this stuff my cable modem could be easily get online. Is it possible that linux caused my modem not to be online?

I need help, really tired of all this stuff... Please just give a little help to this newbie...

tentolga · 08-30-2004, 02:47 AM

Bump!

arno · 08-30-2004, 05:04 PM

You could do two things
1)
Could you ask your provider to check if they gave someone else on their net the same ip address they programmed in your adsl modem
2)
this modem also has an network interface us it to test the connection to the internet ( it should have got a different ip address then the usb port )