Re: [gentoo-user] Need networking help. Can't ping google.

[Mick]

On 10 December 2010 09:40, Keith Dart <keith@×××××××××.biz> wrote:
> === On Fri, 12/10, Dale wrote: ===
>> I did this.  From smoker, I pinged google.  I got the IP address from
>> that.  I then tried to ping google BY IP address on lightening.  It
>> gives me the error "ping: unknown host 72.14.299.99".
>
> ===
>
> That's a different error. That is not a valid address.
>
> So then, smoker is your router. But is your DSL modem also a router? Or
> do you have PPPoE terminating in your smoker?
>
> Your DSL modem is probably a router with NAT. It will need a static IP
> address back to your other network, next hop being smoker.
>
> Better would be to get a hub and connect all hosts (including modem, to
> it.

As Keith says the easiest thing would be to go buy yourself a better
ADSL router (because I suspect that you are running some cheap
half-bridged ISP router) which will act as your ADSL modem, NAT
router, DNS repeater, and LAN firewall, all-in-one.  You should be
able to pick up a cheap cisco or netvanta from ebay.

However, you ain't going to learn much network-wise if you do that.
So, instead you may want to run something like this on smoker (check
man iptables for details):

iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

Using the man pages you can add --match <parameters> to only allow
your lightning box to be processed and anything else dropped.

You will also need to set an additional subnet for your LAN (between
your smoker and lightning boxen).

So all together it could look like this:

Smoker:

NIC eth2

ip: 192.168.1.X
Netmask : 255.255.255.0
Broadcast: 192.168.1.255
gateway: 192.168.1.254 (that's your ADSL router's IP address)

for DNS use your ADSL router's IP address (if it acts as a local
resolver) or your ISP's DNS server address, or OpenDNS ip addresses
(google for it).

Then you need to set up your second smoker NIC like this:

NIC eth0

ip: 192.168.2.X  (different subnet than your DSL network)
Netmask : 255.255.255.0
Broadcast: 192.168.2.255
gateway: 192.168.1.254 (also your ADSL router's IP address)

Finally, on your lightning box you need this:

NIC ethX

ip: 192.168.2.XX (same subnet as your eth0 NIC on smoker, but
different IP of course)
Netmask : 255.255.255.0
Broadcast: 192.168.2.255
gateway: 192.168.2.X  (same as the IP of your eth0 NIC on smoker)

for DNS set up /etc/resolv.conf on lightning the same as for smoker above.

The above should hopefully work.

-- 
Regards,
Mick