Hi all

Hope you can help me with this problem. I've been trying to set up a small home LAN with 4 PC's to initally have all client PCs to access the internet via kppp. All PCs have Mandrake 9. So far I have been unable to access the internet via the clients. This is what I've done so far.

On the server and client PCs, I have configured the following:

/etc/hosts

127.0.0.1 localhost.localdomain localhost
192.168.0.1 server.conference.table server
192.168.0.2 dave.conference.table dave
192.168.0.3 mike.conference.table mike
192.168.0.4 charlie.conference.table charlie
203.43.67.254 ssc.net.au southernstar

On the server only:

/etc/rc.d/rc.local

added to the end:
echo 1 > /proc/sys/net/ip4/ip_forward
iptables -t nat POSTROUTING -o ppp0 -j MASQUERADE

/etc/sysonfig/networking/ifcfg-eth0 was created

DEVICE=eth0
IPADDR=192.168.0.1
NETMASK=255.255.255.0
NETWORK=192.168.0.0
BROADCAST=192.168.0.255
ONBOOT=yes
USERCTL=yes

Also created a link of this file to /etc/sysconfig/network-scripts

/etc/resolv.conf (for both server and clients)

search localdomain
nameserver 127.0.0.1
nameserver 203.43.67.254
nameserver 139.130.4.5
search ssc.net.au local

I didn't do anything to the /etc/sysconfig/network file on the server.

There is no firewall at this time (shorewall not installed).

On the clients, I have done the following:

/etc/rc.d5/s99local

added the line:

/sbin/iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE

/etc/sysconfig/networking/ifcfg-eth0 file created (e.g. on the first client):

DEVICE=eth0
IPADDR=192.168.0.2
NETMASK=255.255.255.0
NETWORK=192.168.0.0
BROADCAST=192.168.0.255
ONBOOT=yes
USERCTL=yes

/etc/sysconfig/network

NETWORKING=yes
FORWARD_IPV4=false
HOSTNAME=dave.conference.table
GATEWAYDEV=eth0
GATEWAY=192.168.0.1

On the server (when I'm connected to my ISP), route -n returns:

Destination Gateway Genmask Flags Metric Ref Use Iface
10.0.0.1 0.0.0.0 255.255.255.255 UH 0 0 0 ppp0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 10.0.0.1 0.0.0.0 UG 0 0 0 ppp0

On the client, route -n returns:

Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 0.0.0.0 255.255.255.255 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 eth0

Can anyone suggest what I'm doing wrong?

Regards

Ray

looks like you have missed the FORWARD chain (I do not know the defaults for the Mandrake so I can be wrong);
post all the ipchains rules

I thought I'd be using iptables rather than ipchains. Which is why I placed the following arguments in rc.local:

echo 1 > /proc/sys/net/ip4/ip_forward
iptables -t nat POSTROUTING -o ppp0 -j MASQUERADE

I can't see why you would need masquerading on the clients.

Can you ping the clients from the server and vice versa?

Yes I can ping the clients from the server and vice versa.

Check you don't have
FORWARD_IPV4=false
in your servers /etc/sysconfig/network file - I'm not sure what the Mandrake default is.

Ah - just noticed the "echo 1" command should be
echo 1 > /proc/sys/net/ipv4/ip_forward
not
echo 1 > /proc/sys/net/ip4/ip_forward

Sorry, I made mistake in my post: 'post all the ipchains rules' - I thought about iptables chains.
See if you have proper FORWARD chain or post all the iptables chains.
If I am right you should be able:
-ping linux host from the each client PC
-ping each client PC from the linux host
-ping any external ip from linux host
but does not ping external ip from any PC client.

Ok, I've placed the "v" in the echo 1 > /proc/sys/net/ipv4/ip_forward script.

I also changed the /etc/sysconfig/network file on the server to:

NETWORKING=yes
FORWARD_IPV4=true
HOSTNAME=server.conference.table
DOMAINNAME=localdomain

Also with the network file on the clients, shouldn't I have FORWARD_IPV4=false as true??

Can anyone provide any advice to fix my problem?

it could have been better if you had it this way on you server and set "FORWARD_IPV4=true" on the clients too: so you can have something like this:
/etc/sysconfig/networking
NETWORKING=yes
FORWARD_IPV4=true
HOST NAME=server.conference.table
DOMAIN NAME=localdomain
on your sverver

while your clients should have something that looks like this;
/etc/sysconfig/network
NETWORKING=

Hi sunnyvic - half your reply was missing. Are you able to repeat it?

Thanks

Hi all

Thanks for all your help so far.

I found that I had "-A" missing from my iptables script for the s99local file, should have been:

iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE

Also, I discovered that iptables hadn't been installed on the server.

I can now access the internet from the client PCs.

Well done - you shouldn't need IP forwarding on the clients as you don't need the m to forward packets so you may want to disable it as a slight security point - not that it matters on a small network though.