[gentoo-user] Sharing an internet connection

[gentoo-user] Sharing an internet connection

[Grant]

I travel with a strong external antenna for picking up faint wireless
signals.  It works great, but my girlfriend struggles to connect with
her built-in antenna.  I do have a travel router (D-Link DWL-G730) so
I'd like to be able to do something like this:

WAN->my laptop->travel router->girlfriend's laptop

I use wicd and I'm not sure how to go about this, especially since my
laptop DHCPs for an IP from the WAN so I'm not sure how to define the
gateway for the travel router when following this:

http://www.gentoo.org/doc/en/home-router-howto.xml

Is there a simple way to pull this off?

- Grant

Re: [gentoo-user] Sharing an internet connection

[Dan Farrell]

On Thu, 12 Mar 2009 13:26:45 -0700
Grant <emailgrant@gmail.com> wrote:

> I travel with a strong external antenna for picking up faint wireless
> signals.  It works great, but my girlfriend struggles to connect with
> her built-in antenna.  I do have a travel router (D-Link DWL-G730) so
> I'd like to be able to do something like this:
 
> WAN->my laptop->travel router->girlfriend's laptop

That sounds right to me.  Read on...

> I use wicd and I'm not sure how to go about this, especially since my
> laptop DHCPs for an IP from the WAN so I'm not sure how to define the
> gateway for the travel router when following this:

I don't have experience with wicd or the DWL-G730, but I did do a
little research on those and have suggestions.  

If I were setting this up myself it would be with another Wifi card in
AP mode, which I'd be running DHCP on.  In that case, the client (in
this case your girlfriend's laptop) would be given a DHCP address and a
default route of my AP's address.  Alternately I might forego the DHCP
server setup and instruct the client to set a particular IP and route
(the route would be my AP's IP).  In either case, nameservers could be
copied directly from "my laptop" to the client's, or "my laptop" could
supply its own IP for nameserver and provide DNS service or proxy
itself.  

"My laptop" would then have a route through the AP for internal traffic,
and use the (dhcp provided) default route for other traffic.
Therefore, the AP would never need to specify the IP of the external
connection.  

The client box would route all traffic through the AP's IP so it
wouldn't need to know the external IP either.  

"My laptop" would have to run IPTables for NAT.  You'll need network
address translation because external IPs like websites won't be able to
route to the client box's IP.  NAT gets around this.  

The AP provided by "my laptop" must also be on a different subnet than
the external network "my laptop" is connected to.  If "my laptop" was
connected to an access point offering a 192.168.1.0/24 subnet, for
example, a seperate subnet like 192.168.2.0/24 ought to be used on the
"client side" of "my laptop".  Personally I'd probably use an rfc class
b subnet since they're rare, or another rare subnet like
192.168.66.0/24.  

> http://www.gentoo.org/doc/en/home-router-howto.xml
> 
> Is there a simple way to pull this off?

In short, no, but it's not too complicated, and the home router guide
will help you, but using your travel router may make things more
complicated.  The travel router probably will itself provide NAT and
DHCP so I'm not sure without playing with one how it would look to set
it up that way.  You might want to provide those services yourself and
use the travel router as an AP instead.  

Re: [gentoo-user] Sharing an internet connection

[b.n.]

Grant ha scritto:
> I travel with a strong external antenna for picking up faint wireless
> signals.  It works great,

May I ask which antenna? It's a long time I'm looking for something like
that but I keep being told that external antennas are often useless (I'm
thinking of the over-the-counter usb stuff)

m.

Re: [gentoo-user] Sharing an internet connection

[Grant]

>> I travel with a strong external antenna for picking up faint wireless
>> signals.  It works great,
>
> May I ask which antenna? It's a long time I'm looking for something like
> that but I keep being told that external antennas are often useless (I'm
> thinking of the over-the-counter usb stuff)
>
> m.

Here it is:

http://www.hawkingtech.com/products/productlist.php?CatID=32&FamID=58&ProdID=152

Pair this with a USB network adapter and a 15 meter USB extender cable
and you're set.  It's a great antenna.

- Grant

Re: [gentoo-user] Sharing an internet connection

[Grant]

>> I travel with a strong external antenna for picking up faint wireless
>> signals.  It works great, but my girlfriend struggles to connect with
>> her built-in antenna.  I do have a travel router (D-Link DWL-G730) so
>> I'd like to be able to do something like this:
>
>> WAN->my laptop->travel router->girlfriend's laptop
>
> That sounds right to me.  Read on...
>
>> I use wicd and I'm not sure how to go about this, especially since my
>> laptop DHCPs for an IP from the WAN so I'm not sure how to define the
>> gateway for the travel router when following this:
>
> I don't have experience with wicd or the DWL-G730, but I did do a
> little research on those and have suggestions.
>
> If I were setting this up myself it would be with another Wifi card in
> AP mode, which I'd be running DHCP on.  In that case, the client (in
> this case your girlfriend's laptop) would be given a DHCP address and a
> default route of my AP's address.  Alternately I might forego the DHCP
> server setup and instruct the client to set a particular IP and route
> (the route would be my AP's IP).  In either case, nameservers could be
> copied directly from "my laptop" to the client's, or "my laptop" could
> supply its own IP for nameserver and provide DNS service or proxy
> itself.
>
> "My laptop" would then have a route through the AP for internal traffic,
> and use the (dhcp provided) default route for other traffic.
> Therefore, the AP would never need to specify the IP of the external
> connection.
>
> The client box would route all traffic through the AP's IP so it
> wouldn't need to know the external IP either.
>
> "My laptop" would have to run IPTables for NAT.  You'll need network
> address translation because external IPs like websites won't be able to
> route to the client box's IP.  NAT gets around this.
>
> The AP provided by "my laptop" must also be on a different subnet than
> the external network "my laptop" is connected to.  If "my laptop" was
> connected to an access point offering a 192.168.1.0/24 subnet, for
> example, a seperate subnet like 192.168.2.0/24 ought to be used on the
> "client side" of "my laptop".  Personally I'd probably use an rfc class
> b subnet since they're rare, or another rare subnet like
> 192.168.66.0/24.
>
>> http://www.gentoo.org/doc/en/home-router-howto.xml
>>
>> Is there a simple way to pull this off?
>
> In short, no, but it's not too complicated, and the home router guide
> will help you, but using your travel router may make things more
> complicated.  The travel router probably will itself provide NAT and
> DHCP so I'm not sure without playing with one how it would look to set
> it up that way.  You might want to provide those services yourself and
> use the travel router as an AP instead.

Thanks Dan.  No matter what I do, I can't get the other laptop to
communicate with my laptop.  It can ping the router which is between
us, but it can't get to the other side.  I've got dnsmasq and
shorewall running on my laptop.  Any idea what the problem could be?

- Grant

Re: [gentoo-user] Sharing an internet connection

[b.n.]

Grant ha scritto:
>>> I travel with a strong external antenna for picking up faint wireless
>>> signals.  It works great,
>> May I ask which antenna? It's a long time I'm looking for something like
>> that but I keep being told that external antennas are often useless (I'm
>> thinking of the over-the-counter usb stuff)
>>
>> m.
> 
> Here it is:
> 
> http://www.hawkingtech.com/products/productlist.php?CatID=32&FamID=58&ProdID=152
> 
> Pair this with a USB network adapter and a 15 meter USB extender cable
> and you're set.  It's a great antenna.

Thanks!

m.

Re: [gentoo-user] Sharing an internet connection

[Dan Farrell]

Hi again.  Sorry I didn't get back to you sooner.  

On Thu, 12 Mar 2009 17:42:55 -0700
Grant <emailgrant@gmail.com> wrote:

> Thanks Dan.  No matter what I do, I can't get the other laptop to
> communicate with my laptop.  It can ping the router which is between
> us, but it can't get to the other side.  I've got dnsmasq and
> shorewall running on my laptop.  Any idea what the problem could be?

Yes; the problem is probably the routing tables.  

> - Grant
> 

Re: [gentoo-user] Sharing an internet connection

[Grant]

> Hi again.  Sorry I didn't get back to you sooner.
>
> On Thu, 12 Mar 2009 17:42:55 -0700
> Grant <emailgrant@gmail.com> wrote:
>
>> Thanks Dan.  No matter what I do, I can't get the other laptop to
>> communicate with my laptop.  It can ping the router which is between
>> us, but it can't get to the other side.  I've got dnsmasq and
>> shorewall running on my laptop.  Any idea what the problem could be?
>
> Yes; the problem is probably the routing tables.

I moved the WAN from wlan0 to ppp0 and things started working.  I
guess I must have made some other change at the same time.  Thanks a
lot for your help.  This is a really slick setup.

- Grant