Network topology configuration problems

Hi

For some time now, I've been using a Netgear DG834G wireless router to
connect my family to the Internet. It has worked perfectly and I've had no
real problems. However, more recently, I started to realise that this
router was quite limited in what it could achieve, for example, no QoS,
which would be very helpful on a shared Internet connection. About a month
ago, I brought a Linksys WRT54GL wireless router and flashed it with
Thibor HyperWRT 15c. My original plan was to hook up this router alongside
my Netgear DG834G and merely use the latter as an ADSL modem with the
former as the real router.

Unfortunately, I've suffered some problems in doing so and I wondered what
I might be doing wrong. My initial plan was to disable the firewall and
NAT on the Netgear (the firewall can't be disabled, so I'd forward all
ports to the Linksys) and connect the first Netgear LAN port to the WAN on
the Linksys. I'd then set the gateway and DNS for the Netgear to the
Internet while setting the Linksys gateway and DNS to the Netgear. I also
set up the LAN IP's so they didn't conflict.

I couldn't get this to work, so I re-enabled NAT and tried again, but
still had no luck. I also made the rather stupid mistake of connecting the
Netgear LAN 1 port to the Linksys LAN port 1, which resulted in an
operational system, but also very poor security. I don't think any damage
was done fortunately in the half an hour before I noticed. Port scan and
DOS attempts were made according to the Netgear logs, but nothing else in
the admittedly short window time sad

Anyway, when I enable either of the two approaches mentioned previously, I
can't get access the Netgear router from the LAN, so I can only assume
that there is something blocking it involving the Linksys WAN interface.
But I can't find anything in the configuration options that would help
with this.

Does anybody know what I might be doing wrong? What is the best way to
hook up a Netgear DG834G and Thibor 15c in this configuration?

Thanks

"Pan" <(E-Mail Removed)> wrote in message
news(E-Mail Removed)...
[snip]
> Does anybody know what I might be doing wrong?

You can't avoid NAT on the Netgear unless you have multiple IP addresses
from your ISP [1]. I'm not sure what you did wrong, the only thing I can
think of that isn't ruled out by what you have written is the IP
configuration (you need two separate IP address ranges, else the Linksys
might end up confused).

[1] Not quite true; some routers can be configured to "pass on" the WAN IP
address via DHCP to a single LAN machine. I am not sure how this works but
it is rather unconventional.

> What is the best way to hook up a Netgear DG834G and Thibor 15c in this
> configuration?

Simplest is to connect a LAN port of the Netgear to the WAN port of the
Linksys and configure things something like this:

Netgear:
- NAT enabled.
- Wireless functionality and DHCP server disabled.
- WAN interface configuration as before.
- LAN interface IP address/mask 192.168.0.1/255.255.255.0.
- Forward all ports to 192.168.0.2.

Linksys:
- NAT enabled.
- WAN interface IP address/mask 192.168.0.2/255.255.255.0.
- WAN interface default gateway 192.168.0.1.
- DNS server 192.168.0.1 or ISP's servers.
- LAN interface IP address/mask 192.168.1.1/255.255.255.0.
- DHCP server enabled if desired.
- Wireless functionality configured as desired.

Statically configured LAN machines (connected via Linksys wireless or LAN
ports):
- IP address/mask 192.168.1.x/255.255.255.0, 2 <= x < 255.
- Default gateway 192.168.1.1.
- DNS server 192.168.1.1, 192.168.0.1 or ISP's servers.

It may be possible - depending on the Netgear's capabilities - to have the
Linksys work as a non-NAT router, but there is not much advantage in my
opinion.

Alex

Hi Alex

On Mon, 07 Aug 2006 17:55:10 +0100, Alex Fraser wrote:

<snip>

>
> You can't avoid NAT on the Netgear unless you have multiple IP addresses
> from your ISP [1]. I'm not sure what you did wrong, the only thing I can
> think of that isn't ruled out by what you have written is the IP
> configuration (you need two separate IP address ranges, else the Linksys
> might end up confused).

Yes, this is one of the two mistakes I made, I didn't realise I'd need a
second subnet. But I guess it makes sense now I think about it.

<snip>

>
> Netgear:
> - NAT enabled.
> - Wireless functionality and DHCP server disabled.
> - WAN interface configuration as before.
> - LAN interface IP address/mask 192.168.0.1/255.255.255.0.
> - Forward all ports to 192.168.0.2.
>
> Linksys:
> - NAT enabled.
> - WAN interface IP address/mask 192.168.0.2/255.255.255.0.

This is the other mistake I made. When I configured the WAN port on the
Linksys, I tried static IP and added the LAN port of the Netgear, but it
informed me that the gateway and IP address couldn't be the same, which
confused me. Now I realise that the information given is for the WAN
port configuration, and not for the destination device as I thought. I
guess it sounds like an obvious mistake now, but it didn't occur to me
at the time that it might be for the WAN port

<snip>

>
> It may be possible - depending on the Netgear's capabilities - to have the
> Linksys work as a non-NAT router, but there is not much advantage in my
> opinion.

The configuration you suggested seems to work fine, so I won't push my
luck trying anything new, even if it is available

Thanks for the help, it was much appreciated

Regards,

Pan