Hi Sanjeev, First of all, please do not piggyback old threads. Always start a new discussion if the topic is different. The reason is that people do not necessarily follow each post and only follow according to the subject line. Now onto your problem.
On Thursday, 26 June 2008, sanjeev shrestha wrote: > Can any one help me? > > I have 2 PCs here at home, I use Ubuntu and my sister uses windows, I > want > to share the internet connection from ubuntu to the PC running > windows. So, your setup is ISP<->modem<-cable->Ubuntu<-cable->windows if I got that right? Can you tell me which is external and internal network? For e.g., eth0 is your external connected to ISP and eth1 is your private LAN (windows box)? > Though I found a tutorial that taught to share the internet > connection, I > could not fix the problem > > Here is what I tried on terminal > > # sudo ifconfig eth1 192.168.1.1 Yup. > # sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE Before setting up masquerade, I recommend you to flush (iptables -F), enable nat and forwarding in your interfaces and start fresh. There are few iptables rules and modules you need to be aware of before masquerading. Take a read at http://newbiedoc.sourceforge.net/networking/homegateway.html > # sudo apt-get install dnsmasq ipmasq Yes sir! that is correct. dnsmasq can be used instead of bind and on top of that it also provides dhcp to your client computers (in your case I assume MS windows) in your home network. > # sudo /etc/init.d/dnsmasq restart Try to fire up a network protocol analyser (keepin it handy is always a wise idea). One good one I use is tcpdump which you dump to ethereal/wireshark for investigating the problem further but a good way is just use command line: $ sudo tcpdump -i any -p -n EXPRESSION where EXPRESSION can be such as 'not src ip a.b.c.d' for example. More info is tcpdump man page. > # sudo dpkg-reconfigure ipmasq On my network, I never use ipmasq. I use only iptables and go straight for static IPs in clients (for e.g., windows) and the gateway (for e.g., ubuntu). On any client, you need make sure you you set the gateway,netmask and DNS correctly. The gateway is usually the ubuntu box's internal interface address for simple home networking and dns can set be your ISP dns or the ubuntu box IP. > and then again > > # sudo ifconfig eth1 192.168.1.1 Why is eth1 192.168.1.1 as well? If this is internal LAN, it should have different IP address. For e.g., you could have it as 10.1.1.1 (which IANA allows for private IP such as home networking) and is usually blackholed at border gateways and your external IP as 192.168.1.101 that is available from your router (the route that connects to your ISP). > # sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE Go through http://newbiedoc.sourceforge.net/networking/homegateway.html. This was the article I started with some winter back. > Added the line "net.ipv4.ip_forward = 1" to /etc/sysctl.conf Yes. That's correct. You can change it dynamically via /proc/sys/net/ipv4/ip_forward (by doing " echo 1 > /proc/sys/net/ipv4/ip_forwar ") but at the moment it is fine also. > And rebooted. No need to reboot for Ubuntu box. Reboot for MS Windows should also be not needed. > Still I could not share the internet. Also, there is a seperate proper mailing list for Ubuntu discussion - [EMAIL PROTECTED] and [EMAIL PROTECTED] Have a look @ http://wiki.ubuntu.org.np and http://wiki.ubuntu.com. Goodluck and always post a new thread how it goes. Please do not piggyback old one. :) -- cheers #define HIGH 0xcoffee
signature.asc
Description: Digital signature
