LinuxQuestions.org - Network sharing doesn't work more then a few seconds

- Debian (https://www.linuxquestions.org/questions/debian-26/)

- - Network sharing doesn't work more then a few seconds (https://www.linuxquestions.org/questions/debian-26/network-sharing-doesnt-work-more-then-a-few-seconds-172212/)

Network sharing doesn't work more then a few seconds

Hi,
I'm trying to share my Internet cable connection to the internal LAN (W2K),
I used several scripts the current one was made by firestarter.
My problem is:
if I surf the Internet in the server it's OK.
But if I surf from the workstations it works for 3~6 minutes and then the network comes down, I can't ping the server or the workstation.

After I stop the network and restart (network and firewall) it work the same way.

What is the possible problem.

Thank you in advance.

spiri

Are you having dynamic ip address? Does running dhcp client again help?

Hi,
I have static IPs and no dhcp-client
try to install dhcp-client but it says can't find dhcp.conf

Do you think that I should use dinamic IP, my problem is samba.

Thank you.

You have static ip also to internet?
How the samba is your problem? Wasn't the problem sharing the internet connection?

Do you have two nics or are you trying to do the thing within same wires?

You have static ip also to internet?
-No!
How the samba is your problem? Wasn't the problem sharing the internet connection?
-Yes, but if I start using dinamic IPs the serve can't find workstations, I think.

Do you have two nics or are you trying to do the thing within same wires?
-I had 2 nics: eth0 -> LAN; eth1->Internet.

Thanks.

spiri

Hmm.. my first idea was that the dhcp-client is not running on the background and the ip-address expires, but it doesn't explain why the server stops pinging to the workstation.

It is also possible that the netcard just locks up for some reason. I have had this kind of lockup problem with some d-link cards using via-rhine driver and with somewhat old kernels (some 2.4.18 and older).

You could see the syslog and dmesg from the server if there are something netcard related (like "eth transmit timeout: reseting") problems. Also is it the firewall that hangs or the networking itsefl. That is, does the ping packets start transmiting again if you drop the firewall

Code:

iptables -F

iptables -P INPUT ACCEPT

iptables -P OUTPUT ACCEPT

.

More questions: What kernel are you using? Does the packet counters increase after the hangup? Does there come some error, dropped or overruns when you look the interface with ifconfig?

Hi,
thank you for your help.

I remove the firestarter script, and use this one:

Code:

#!/bin/bash

modprobe ip_tables

modprobe iptable_filter

modprobe ip_conntrack

modprobe iptable_nat

modprobe ipt_MASQUERADE





iptables -F

iptables -X

iptables -Z

iptables -t nat -F

iptables -t nat -X

iptables -t nat -Z



iptables -P INPUT ACCEPT

iptables -P FORWARD DROP

iptables -P OUTPUT ACCEPT

iptables -t nat -P PREROUTING ACCEPT

iptables -t nat -P POSTROUTING ACCEPT

iptables -t nat -P OUTPUT ACCEPT



echo 1 > /proc/sys/net/ipv4/ip_forward

iptables -A POSTROUTING -t nat -o eth1 -j MASQUERADE

iptables -A FORWARD -i eth0 -o eth1 -j ACCEPT

iptables -A FORWARD -i eth1 -o eth0 -j ACCEPT

with this scrip it works more time, 2 or 3 minutes, and
the network is up so I can ping the workstations and the the nics are in the ifconfig.

Quote:

More questions: What kernel are you using? Does the packet counters increase after the hangup? Does there come some error, dropped or overruns when you look the interface with ifconfig?

linux 2.4.25-1-386 debian sarge

It could be a script problem or a hardware problem. I'm using a Gigabyte GA-7N400 Pro 2 with a r8139 module (eth1=internet) the lan nic is a US Robotics (tulip module->lan).
Maybe I had too change the nics ?

regards,

spiri

Hmm.. does there come any errors for the interfaces?

For me there is one error package (happened at the initialization time when connecting the wires)

Code:

root@perhonen:~# ifconfig

eth0      Link encap:Ethernet  HWaddr 00:50:FC:FE:7E:CB  

          inet addr:192.168.1.3  Bcast:192.168.1.255  Mask:255.255.255.0

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:20067217 errors:0 dropped:0 overruns:0 frame:0

          TX packets:27068198 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000 

          RX bytes:2356224898 (2.1 GiB)  TX bytes:0 (0.0 b)

          Interrupt:16 Base address:0xce00 



eth1      Link encap:Ethernet  HWaddr 00:E0:81:10:4E:69  

          inet addr:***.***.***.****  Bcast:***.***.***.255  Mask:255.255.254.0

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:8508261 errors:0 dropped:0 overruns:0 frame:0

          TX packets:4470862 errors:1 dropped:0 overruns:0 carrier:1

          collisions:915806 txqueuelen:1000 

          RX bytes:215281142 (205.3 MiB)  TX bytes:700039323 (667.6 MiB)

          Interrupt:19 Base address:0xee80 Memory:febfe000-febfe038 



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:507085 errors:0 dropped:0 overruns:0 frame:0

          TX packets:507085 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:0 

          RX bytes:194418960 (185.4 MiB)  TX bytes:194418960 (185.4 MiB)

What are the last lines of dmesg?

Ok, now the machines ping eachother; does the network work afther few minutes from the server doing the routing? If not, is the dhcp-client still running?
(something like:

Code:

root 467 1 0 Apr09 ? 00:00:00 dhclient -pf /var/run/dhclient.eth1.pid eth1

My ifconfig after it as broken the connection:

Code:

debian:/home/toto# ifconfig

eth0      Link encap:Ethernet  HWaddr 00:C0:49:B3:59:F0

          inet addr:192.168.0.1  Bcast:192.168.0.255  Mask:255.255.255.0

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:1396 errors:0 dropped:65 overruns:0 frame:0

          TX packets:1731 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:186451 (182.0 KiB)  TX bytes:1618435 (1.5 MiB)

          Interrupt:5 Base address:0xa000

 

eth1      Link encap:Ethernet  HWaddr 00:0D:61:20:C5:F3

          inet addr:***.***.***.***  Bcast:***.***.***.***  Mask:255.255.254.0

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:3713 errors:0 dropped:0 overruns:0 frame:0

          TX packets:3034 errors:0 dropped:182 overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:2996708 (2.8 MiB)  TX bytes:0 (0.0 b)

          Interrupt:5 Base address:0x2000

 

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:171 errors:0 dropped:0 overruns:0 frame:0

          TX packets:171 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:0

          RX bytes:24011 (23.4 KiB)  TX bytes:24011 (23.4 KiB)

 

debian:/home/toto# ping 192.168.0.6

PING 192.168.0.6 (192.168.0.6) 56(84) bytes of data.

 

--- 192.168.0.6 ping statistics ---

3 packets transmitted, 0 received, 100% packet loss, time 2015ms

last lines of dmesg

Code:

debian:/home/toto# tail /var/log/dmesg

usb-uhci.c: v1.275:USB Universal Host Controller Interface driver

hub.c: new USB device 00:02.2-5, assigned address 2

usb.c: USB device 2 (vend/prod 0xf5f/0x1320) is not claimed by any active driver.

hub.c: new USB device 00:02.1-3, assigned address 2

ip_conntrack version 2.1 (4095 buckets, 32760 max) - 292 bytes per conntrack

ip_tables: (C) 2000-2002 Netfilter core team

usb_control/bulk_msg: timeout

usb-ohci.c: unlink URB timeout

usb.c: USB device not accepting new address=2 (error=-110)

hub.c: new USB device 00:02.1-3, assigned address 3

the network stops running and the dhcp-client is running.

I had to stop the network start it and run the iptables script to acces the internet from the server.

thank you

regards
spiri

Someone send this post to debian-firewall@lists.debian.org

Quote:

>These two problems look the same to me and I have/had a third. Dose any one know if these issues were resolved and if there is a problem with

Debian's or Linux's iptables? I'm thinking something in a recent

update,

two weekes past, has caused this. Many other ppl may be effected but

are

unaware or not using iptables.

This should be a BIG RED FLAG!!!