Airport Express: same IP range as WAN IP

[arnoz]

Hi,

I would like to force my Airport Express to use the same IP range 192.168.1.x as the WAN IP it receives.
To make it simple: modem/router connected to DSL => Airport Express connected via Ethernet and sharing WiFi

The set up is strange and double NAT sucks, I know. To make it short: I need to use it that way and cannot use bridge mode.

But I would like the Airport to use that 192.168.1.x private IP range and AIrport Utility won't let me do that :-(

 

[lexvo]

Why can't you use bridge mode?

I'm afraid it is the only possible way, because as far as I know a network has to have a single point where IP's are distributed.

 

[arnoz]

Modem/router is in house A, AIrport is in "house" B. It's connected via a 30 meters shielded Ethernet cable.
I can't use bridge mode because the router in A also has 2 ethernet ports for TV which are deactivated if we put the router in bridge.
A has IP 192.168.1.1, gives IP from 192.168.1.2 to 1.49. Airport has 1.50 and I would like it to ditribute IP from 192.168.1.51 to 99.

 

[lexvo]

Just to be sure: I meant the Airport Express should be in bridge mode.

 

[arnoz]

Just to be sure: I meant the Airport Express should be in bridge mode.

Oh OK, sorry. But in that case I miss a lot of easy features of the Airport, mainly the port forwarding especially with a OS Server machine.
The modem/router in A is a piece of junk and port forward sucks. As well as other features.
And in bridge would AirPrint/Tunes work?

Thanks.

 

[lexvo]

Airtunes/Airplay works in bridgemode (I know because I have this at home), I think AirPrint should also work.

Do you need port forwarding for an OS server machine?

 

[arnoz]

I need port forwarding to the OS X server for web, SSH, remote desktop, AFP.
I also need port forwarding SSH to two other computers.

 

[lexvo]

I think because of your router A is distributing IP-adresses, port forwarding also has to be done by that router.

 

[arnoz]

Yes and no. At the moment there is no port forwarding on it and everything works.
But I don't want to add port forwarding rule in it because it's very badly made. All I want to be able to do is select the private IP range I want from the Airport Express which at the moment it won't let me do.

 

[waw74]

so it goes
internet -> router A -> router B (your express)?

A has to have some forwarding set on it, or traffic will never get in off the internet. or all traffic gets in off the network, which is a bad option.

you would have to forward ports on both A & B to get the traffic to your network.
and if you want devices in both locations to be able to see each other (for airtunes and printing and such) you need to be in bridge mode, otherwise you will only have it from stuff connected to router B.

if aren't in bridge mode and could set up
mac connected to router B with 192.168.1.70
computer connected to router A with 192.168.1.5

the .5 can't reach .70 directly, you would have to go through the express
and if router A was looking for .1.70, it wouldn't be able to find it.

if you insist on not being in bridge mode, then you'll need to set the express up to pass out IPs on a different subnet so 192.168.2.X, then on router A, forward all the ports you want to the express (.1.50) and then have the express forward the ports to the appropriate IP on it's network (.2.X)

 

[arnoz]

Indeed internet -> router A -> router B

In A, the Airport Express's MAC address is in static IP and DMZ mode. So all ports are open from A to B which is why I can access the remote desktop computer connected on B without a problem, outside the LAN.

AirTunes from location A is no problem, I don't care.

What you suggest finally is actually what I have at the moment (except DMZ in router A to AIrport rather than port forward).
But I still have some issues because of double private IP ranges: i can't use Back To My Mac or I cannot connect to my dyndns address from within the LAN. The only way inside the LAN to access the server is to use its private IP address.
So abc.dyndns.org should work in Screen SHaring but it doesn't, only way is 10.0.0.x