Internet Connection Sharing

[alexcwagner]

I have a Guruplug Standard, and I was wondering if anyone has managed to use one of these to act as a wi-fi client and then share the connection with another computer.  I did manage, with great difficulty, to figure out how to get it to act as a wi-fi client, though apparently it won't be "stable" unless I update the kernel and some drivers (which I haven't quite figured out how to do yet), but as far as turning around and sharing the connection via Ethernet, I haven't a clue.

[cjm]

You can use iptables to set up NAT (network address translation). Here's a short explanation:

http://www.revsys.com/writings/quicktips/nat.html

You may want to use a more detailed set up with basic firewall settings, of course. If you're using something like pppoe (e.g. a DSL modem), you may also want to add something like this at the end to make sure your maximum segment size matches the maximum supported over pppoe connections (braindead firewall configurations blocking ICMP all over the Internet will otherwise wreak havok with the automatic detection of the maximum segment size (path MTU discovery); the effect is, for example, that some web sites behind such firewall configurations will appear to hang and never finish loading):

Code:

iptables -A FORWARD -s 192.168.0.0/255.255.0.0 ! -d 192.168.0.0/255.255.0.0 -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu

(this assumes you're using an address in the 192.168.x.x range for your LAN)

Thanks,
--Christian

[alexcwagner]

Yeah, okay, that sounds plausible.  I'll try it when I get home.

Out of curiosity... have you actually tried this?

[cjm]

I'm using my plug as file, mail and Internet server and it's doing NAT for the other computers in the house. So, yes, I'm using iptables to set up NAT and it works perfectly fine. Although my iptables set up includes firewall settings as well...

Thanks,
--Christian

[yasir]

It is too easy

You can share with wire or wifi

[cjm]

Which part don't you get?

BTW, I just realized that the command I posted above regarding max segment size missed the parameter for the correct table(mangle):

Code:

iptables -t mangle -A FORWARD -s 192.168.0.0/255.255.0.0 ! -d 192.168.0.0/255.255.0.0 -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu

[alexcwagner]

I still haven't tried this yet; I want to wait until I have a significant block of time to dedicate to this, in case it doesn't work right away.  I'll post something about it either way when I finally get around to doing this.

Has anyone successfully followed the wiki instructions for setting the guruplug as a "stable" wifi client, using the compiled versions given in the article?  If not, I guess I'll have to learn how to compile all this stuff myself. :-(  Though... then again, it'll probably be good for me to learn.

http://plugcomputer.org/plugwiki/index.php/Setting_GuruPlug_to_be_a_stable_WiFi_Client