70% packet loss
 

I have two computers: winXP in one and linux(debian) in other.
Linux is my router, so there is two network cards in it.
eth0 is out and eth1 to winxp.

my iptables settings are:

modprobe ipt_MASQUERADE
iptables -F; iptables -t nat -F; iptables -t mangle -F
iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to xxx.xxx.xx.116
echo 1 > /proc/sys/net/ipv4/ip_forward
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -m state --state NEW -i ! eth0 -j ACCEPT
iptables -P INPUT DROP
iptables -A FORWARD -i eth0 -o eth0 -j REJECT

route -n gives:
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
xxx.xxx.xx.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
0.0.0.0 xxx.xxx.xx.1 0.0.0.0 UG 0 0 0 eth0

so eth0 ip is xxx.xxx.xx.116
(of course x's are replaced by the real numbers)

eth1 ip is 192.168.1.1

winxp ip is 192.168.1.100
gateway is 192.168.1.1


It worked a while with these settings, but now it does not. I don't know
what is the problem.. I have made some configuration, but not concerning about interfaces..

linux can ping winxp, but 58% packet loss

winxp can ping linux, but 75% packet loss.

So network works very very showly with winxp. It finds some pages, some even pretty quick (like google).. But it doesn't work like it has been working.
What can be the problem here?

logon to your linux box and ping either the gateway (your isp) or some other internet site like google. Do you still have a lot of packet loss? (yes/no)

Describe the physical layer between your linux box and the winxp box. Hub, switch, cross over cable?

Do you own a cat? (mine chews my cables.. bad kitty!)

Do you have other ip addressable devices are connected to your inside interface of your linux box? (computers, wireless access points, anything that can take an ip address)

There are lots of reasons for packet loss. With more details maybe we can identify the problem.

-b

linux box pings fine isp gateway and google etc. and network is working fine with linux.

there is a cross over cable, and i don't have a cat.

i have only these two machines. no wireless or anything else.

Hmm.. no kitty cat. Ok.

There are a few possibilities.

1. Replace the crossover cable with another crossover that you know is good.
2. Double check the MAC address of the win box and linux inside interface. They should not be the same. Long shot but I've seen this happen before and cause packet loss.
3. Either replace the linux box inside interface nic and / or the win xp nic or connect them to different computers (a laptop works nice) and see if you still get packet loss or which one is the culprit.
4. If you have service pack 2 installed on your XP box try turning off the firewall for testing purposes. May require a reboot.. stupid windows.

-b

Hi bingviini,

What happens if you reboot your linux box that's acting as the router?

Actually, before trying that, what happens if you swap out the cable between your 2 machines for a working crossover cable?

Cheers,

Steve

Sorry guys for bothering you.. the cable was only broken ..

I don't understand how it broke down.. I haven't even touched it.
Maybe it was some cheap shit or something.