my ISP provide me address 192.168.41.4 and 192.168.41.5 (private address)
That's a strange approach for an ISP. Reads more like cheaply shared Internet connection, kind of a design low cost office spaces to provide "Internet".
Does this mean your "ISP" does just allow you to use two IP addresses on a much bigger IP subnet, like 192.168.41.0/24 or 255.255.255.0 subnet?
And in the original set-up you had used a shared netwok where many more devices/offices are connected, for a single computer (on .5) and one server (on .4)?
and now i have one interface from my ISP one cable.
How were the two systems (computer, server) connected before? Either your ISP (ready to me more like a building network or office space provider) connected before? Are there two ports available to you?
on 192.168.41.4 i have DMZ and my exterenal address is conected. this address i set on my server
i put it on RAX20
Does this mean there is a public routeable IP address NATed 1-1 so all ports are consumer device like "DMZ" available, and here you had a connected a server before...
You could to this, but the server will need a lan ip from the RAX20, reserverd, like 192.168.1.5, and configured the DMZ to this IP again. Very unlucky to have that many NAT routers in the line then.
I want have wifi for cell phone user on IP 192.168.41.5 and server should work on address 192.168.41.4 (because of DMZ)
When i set router on access point mode server work but only one user on cell phone can connect when he set IP 192.168.41.5 on his wifi
With just two iP addresses from this subnet, you can't connect more than two systems. Either you challenge this "ISP" to reserve a bigger IP range in the 192.168.41.0/[unknown subnet mask here] so you can add the router (in Access Point mode), and muliple mobile phones ... but for these you should have DHCP service, as fixed IPs just for a specific site on a mobile are unhandy on a mobile device. And here the unknonw other use of this "Internet" network does come in again... Want is nice - but you simply can't ...
Could someone help me ? or explain what i do wrong 🙂
If this "ISP" can't help any further (say assigning more IP addesses and have a DHCP service for your office network) you need some redesign.
What I would do with two "Internet" addresses available (one as DMZ port):
Build a dedicated LAN using your router, e.g. the RAX20, on a network different than 192.168.41.0, ...
In case you have dedicated ports on the wall for both .4 and .5 systems, no switch required - just use what's there and readily available. Otherwise, connect a small switch to one of the ISP ports, to the server (keep numbering, DMZ .4 et all), and to the RAX20 WAN/Internet port (.5).
Configure an additional network adapter on the server to router LAN IP subnet.
Set-up your WLAN on the router
Enjoy your own local [W]LAN.
optional: Change the server config in a way that only Internet-accessible services are available on the adapter hanging on the DMZ port.
Regards,
-Kurt
PS. Very difficult to Google a solution if one does not know what to search for...
