Comments on: Iptables: How-to Share your internet connection http://www.debuntu.org/iptables-how-to-share-your-internet-connection/ Debian/Ubuntu Tips and Tricks Tue, 21 May 2013 04:29:54 +0000 hourly 1 http://wordpress.org/?v=3.5.1 By: chantra http://www.debuntu.org/iptables-how-to-share-your-internet-connection/#comment-137858 chantra Tue, 21 May 2013 04:29:54 +0000 http://www.debuntu.org/?p=442#comment-137858 Nadia, You router is most likely getting its gateway/dns from your ADSL provider with dhcp.
On you router, your eth1 should look like:

auto eth1
iface eth1 inet static
address 192.168.0.1
netmask 255.255.255.0

Your PC on your LAN has to use your router as a gateway, its eth0 config should look like:

# Local Network eth0
auto eth0
iface eth0 inet static
address 192.168.0.2
netmask 255.255.255.0
gateway 192.168.0.1
dns-nameservers my_dns

]]> By: nadia http://www.debuntu.org/iptables-how-to-share-your-internet-connection/#comment-137851 nadia Mon, 20 May 2013 23:14:14 +0000 http://www.debuntu.org/?p=442#comment-137851 i well i do not know what to do now

my settings of my firewall :

# The loopback network interface
auto lo
iface lo inet loopback

# ADSL eth2

# Local Network eth1 ….interfaces for my LAN switch
auto eth1
iface eth1 inet static
address 192.168.0.1
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.255
gateway 192.168.0.254
dns-nameservers my_dns

on the pc of my LAN :

# The loopback network interface
auto lo
iface lo inet loopback

# Local Network eth0
auto eth0
iface eth0 inet static
address 192.168.0.2
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.255
gateway 192.168.0.254
dns-nameservers my_dns

for the last test i have only do :
iptables -t nat -A POSTROUTING -o $WAN -j MASQUERADE

thanks

]]> By: nadia http://www.debuntu.org/iptables-how-to-share-your-internet-connection/#comment-137730 nadia Wed, 15 May 2013 00:17:58 +0000 http://www.debuntu.org/?p=442#comment-137730 hi well i never thaught that a gateway will be 192.168.0.254! not from website like https://help.ubuntu.com/12.10/serverguide/network-configuration.html

so right now on pc from my LAN the basic settings are :
ip 192.168.0.4
netmask 255.255.255.0
gateway 192.168.0.254

and on my firewall
the eth2 is my adsl interfaces
and
the LAN interfaces :

auto eth1
iface eth1 inet static
address 192.168.0.1
netmask 255.255.255.0
gateway 192.168.0.254
dns-nameservers my_dns_ip

my LAN still not ping google.com

]]> By: chantra http://www.debuntu.org/iptables-how-to-share-your-internet-connection/#comment-137707 chantra Mon, 13 May 2013 03:16:42 +0000 http://www.debuntu.org/?p=442#comment-137707 your /etc/network/interfaces does not look right syntactically, and even if it did, ip 192.168.0.1 for your lan pc with gateway 192.168.0.1 is plain wrong. Googling should help you solving these kind of issues. http://wiki.debian.org/NetworkConfiguration contains great material on setting up your network interfaces in Debian.

]]> By: Nadia http://www.debuntu.org/iptables-how-to-share-your-internet-connection/#comment-137696 Nadia Sun, 12 May 2013 02:35:12 +0000 http://www.debuntu.org/?p=442#comment-137696 hi

if i do only this rule iptables -t nat -A POSTROUTING -o -j MASQUERADE nothing work the lan don’t go outside

the 2 interfaces on my firewall when i do ethtool or mii-tool … respond link ok
i have change cable from the switch to firewall same error

yes here is my config from my LAN pc in /etc/network/interfaces

ip 192.168.0.1/24
gateway 192.168.0.1
netmask 255.255.255.0
dns-nameserver my_dns
and the usual network broadcast settings

when i do traceroute 8.8.8.8 goes nowhere * * * *…. all the 30 hops

thanks for your help

]]> By: chantra http://www.debuntu.org/iptables-how-to-share-your-internet-connection/#comment-137694 chantra Sat, 11 May 2013 17:44:35 +0000 http://www.debuntu.org/?p=442#comment-137694 Hi Nadia,

There could be thousand reason why your settings are not working. Did you try to use the 1 simple iptables rule to share your connection?
iptables -t nat -A POSTROUTING -o -j MASQUERADE

Your host unreacheable issue sound like a routing issue. Do you give a default route to your LAN devices?

Have you tried to traceroute do a known destination like 8.8.8.8 (google dns).

]]> By: nadia http://www.debuntu.org/iptables-how-to-share-your-internet-connection/#comment-137693 nadia Sat, 11 May 2013 17:11:30 +0000 http://www.debuntu.org/?p=442#comment-137693 still working on that but now i think i will take a break, still get the host destination unreachable error from the LAN trying to ping outside the world

and also i saw that nobody help me since 10 days so i will take a break.

]]> By: nadia http://www.debuntu.org/iptables-how-to-share-your-internet-connection/#comment-137681 nadia Thu, 09 May 2013 20:03:21 +0000 http://www.debuntu.org/?p=442#comment-137681 today i had change the cable to see if it’s ok between the switch and the firewall and still get the same dest. host unreachable error. so it’s not the rj45 cable the problem.

keep working

]]> By: nadia http://www.debuntu.org/iptables-how-to-share-your-internet-connection/#comment-137676 nadia Thu, 09 May 2013 02:14:53 +0000 http://www.debuntu.org/?p=442#comment-137676 i also had an error on my netmask (before it was LAN : 192.168.1.1… and 255.255.255.0 i changed for 255.255.255.0 but 192.168.0.1)

still have destination host unreachable from my LAN to out…

keep working….

]]> By: nadia http://www.debuntu.org/iptables-how-to-share-your-internet-connection/#comment-137674 nadia Wed, 08 May 2013 23:25:15 +0000 http://www.debuntu.org/?p=442#comment-137674 i was validating the dns and some errors were in my configuration. so now the dns are ok on each configuration of interfaces LAN and WAN

so now between pc from the LAN they can ping each others.
192.168.1.4 ping 192.168.1.2 ….

but both received destination unreachable when they do ping http://www.google.com or ping ip_google
both cannot ping dns1 of my firewall, but can ping my ip_static

my firewall can ping all pcs from my LAN
everything is ok for my firewall

maybe a rules?

nadia

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