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Old 12-14-2005, 06:39 PM   #1
Notwerk
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Registered: Apr 2005
Location: Jordan
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Local network can't access Internet (Server can)


Hi.....

I'm running Fedora Core 3 with dual network interfaces on a home network server. Got dhcpd up and the local network (on eth0) is running. Got the server machine to access the internet (eth1 -> ppp0, since i'm using a BRIDGED DSL modem). However, machines on the local network can't access the Internet. I checked iptables, route, resolv.conf & dhcpd.conf, but couldn't find the reason. Could someone help me out here. I could have missed something... cause i'm not that experienced with linux yet....

Thanx
 
Old 12-15-2005, 02:50 AM   #2
fouldsy
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If the computers on your internal network are connecting to the Internet through your server, you'll need to ensure you have iptables setup correctly for masquearding and ip_forwarding as well as NAT. There are some good documents on the Tutorials on this website. Maybe show us what iptable rules you already have in place as it might be they're just not quite right since you seem to have done everything else.
 
Old 12-15-2005, 03:19 AM   #3
Notwerk
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Thanx fouldsy for the reply....

edit:
I just got it work .... i dug around and found that i didn't add a "GATEWAYDEV=eth1" to /etc/sysconfig/network. The reply posted below was posted earlier, but any recommendations regarding the firewall rules would be very welcome...

[Previous Reply]
I checked iptables again.... the rules i have are as follows (couldn't post the output directly from that machine, sorry):

1. Filter (Default DROP policy):
1.1 INPUT:
1.1.1 Allow ALL traffic into loopback
1.1.2 Allow ALL traffic if source & destination are on the local network
1.1.3 Allow traffic from ppp0 if state is RELATED, ESTABLISHED
1.1.4 Allow TCP SYN traffic from ppp0 on the following ports (21; 22; 25; 80; 110; 443)
1.2 FORWARD:
1.2.1 Allow ALL traffic from eth0 to ppp0
1.2.2 Allow traffic from ppp0 to anywhere if state is RELATED, ESTABLISHED
1.3 OUTPUT:
1.3.1 Allow ALL traffic out loopback
1.3.2 Allow ALL traffic if source & destination are on the local network
1.3.3 Allow ALL traffic out ppp0
2. NAT Table: (Default ACCEPT policy)
2.1 PREROUTING:
EMPTY
2.2 POSTROUTING:
2.2.1 MASQUERADE all traffic coming in from anywhere and going out ppp0 if the source is on the local network.
2.3 OUTPUT:
EMPTY
3. MANGLE (Default ACCEPT policy)
EMPTY

Any ideas?

edit: Also checked that ipv4 forwarding is on, could it be i need to modprobe something for iptables (got ip_conntrack & ip_conntrack_ftp)?
[PREVIOUS REPLY END]

Last edited by Notwerk; 12-15-2005 at 05:54 AM.
 
  


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