[kwlug-disc] IP addresses and gateways--my google-fu seems to be lacking

[Rashkae]

On 14-01-16 01:18 PM, R. Brent Clements wrote:
> I was using an Ethernet-over-power device until a couple days ago when
> one end of it burned out.  I am trying to configure my old netbook to
> connect wirelessly to the downstairs router (easy) and share the
> internet connection with the network of computers in my bedroom.
> Whenever I attach the network cable to the system I lose the internet.
>   I can ping the ip address of both sides of the "router" computer, but
> nothing beyond that.  I am using static ip addresses for the inner
> network in the 192.168.10 range, and the wireless address is
> 192.168.1.65 assigned dynamically from the wireless router downstairs.
>
> I am wondering what gateway address I need to assign to the lan-side
> eth0.  I have followed the instructions on several sites about
> configuring iptables.  It seems like the netbook is losing the
> internet when I have two interfaces active, even tho only one has an
> internet connection.
> Brent

The gateway should be the IP address of your router, (Probably 
192.168.1.1, but you'll have to check your Ip settings when you connect 
to the router wirelessly.)  This should get assigned automatically with 
the DHCP

The static 192.168.10.x IP on the netbook which is acting as a router 
should not have a gateway address at all.

You will have to use Ip tables / netfilter to share the Internet with 
other devices on your network.  The gateway for those *other* devices 
will be 192.168.10.x (The IP address of your netbook.

Note: You will probably be much better off buying a small TP-Link (or 
other compatible router.) and configure it in bridge mode.  So instead 
of being an wireless access point, the router will be a wireless client 
to your existing network, and will bridge the wireless to LAN, (and all 
attached Lan devices will be on the same 192.168.1.x subnet.)  Just be 
sure to disable the DHCP server on the router, and it should work well.