I have a local network on a router. I want to connect it to the internet using another router from my `ISP`. The internet router from my `ISP` has a static IP that can be reached from the internet. 
What I want to achieve is to be able to reach a client server application running on the LAN network from the internet.

```
LAN (192.168.1.1)
+------+------+-------+        +---------+
|      |      |       |        |         | 
PC1   PC2     PC3     LAN Router      Router from ISP (stati IP - 41.58.163.84)

```

The router from ISP also have the following details

```
subnet mask - 255.255.255.255
Default Gateway: 10.1.0.100
DNS: 41.222.70.179

```

After setting the internet configuration on the `LAN` router, when I try to save it, I get the error message that

```
IP address and gateway are not in the same subnet mask.

```

Below are my settings:

```
Internet IP address: 41.58.163.84 (the static IP from my ISP)
subnet mask: 255.255.255.255 (From my ISP)
Default gateway: 192.168.1.1 (Router IP, the LAN router and the internet router I'm using have the same IP which I used as the default gateway)
DNS1: 41.222.70.100

```

I'm not sure the Default Gateway is correct. 

Please what am I doing wrong?