Change the defaut gateway on a NatNetwork

[SFLegion]

Hi,
I was wondering if it is possible to change the default gateway provided by the DHCP of a NatNetwork ?
I would like to use the x.x.x.1 address on one of my hosts but she is already taken by the gateway.
I'm using the Virtualbox 5.1.16.

Thank for helping.

[socratis]

Please do not use x.x.x.1 to describe private networks, you're not exposing absolutely nothing. It's a private network! I can't get to it!

So, do you mean that you want to change the default NATservice gateway from 10.0.2.1 to something else, because you already have a computer with an IP of 10.0.2.1?

[SFLegion]

I have configured a NatNetwork on 203.2.2.0/24 and I wan to give the 203.2.2.1 address to one of my guess.
The problem is that the default gateway is already on 203.2.2.1 and I didn't find any option on the GUI to change that.

[socratis]

I have configured a NatNetwork on 203.2.2.0/24

Why? Do you realize that the NATservice (I prefer that name; less confusion) will *not* be seen by your physical network, no matter what address you give it? If you want your VM to be seen by the rest of the network you don't need NATservice, you need Bridged.

Please read ch. 6.2. Introduction to networking modes and take a look at the table to see a quick overview what's available with each network mode. Again, NATservice will *not* be visible to the rest of your network.

[SFLegion]

I have no need for interaction between physical and virtual network here, the reason behind this choice is that I need my guess to have access to Internet while having the possibility to choose the network address ( 203.2.2.0/24 here).

btw: Sorry if my English is wrong, this is not my native language.

[socratis]

Your English is just fine. But, with the NATnetwork you *will* get Internet access, no matter what address range you have picked. That's the idea. I would suggest to remove the NATnetwork that you've created, add a new one and stick with the defaults (10.0.2.0/24). You *will* get access to the internet.

while having the possibility to choose the network address ( 203.2.2.0/24 here).

Why? What do you want to do? Why does it have to be in that range? It offers nothing more than confusion if you ask me. Keep your physical and virtual networks separated.

[SFLegion]

The guess I'm talking about is a firewall that have 3 network interface two on private host network ( 172.16.17.0/29 and 192.168.17.0/24) and the third interface (on the network 203.2.2.0/24) is mean to provide Internet to all the behind virtual network.I also do NAT on the outside on this thrid interface using IP of interface (I want this interface to be 203.2.2.1) in order to put to the test the NAT capability of my firewall, I'm aware that this IP will be retranslated while routing on the Internet.

I'm student, this something I was asked to do, so yes I want my network to be in that precise range.

[BillG]

Your English is fine. It is what you are trying to do which does not make sense. I now see why you are trying to do it, but it is a complete waste of time and will prove nothing. It makes no difference at all what the IP address on the "public" side of a NAT router is. It will make no difference to how your firewall works. Giving it a public IP does not make it a public network and does not change how NAT works.
NAT was designed originally to allow many private IP addresses to share on public IP, but it has found many other uses in all-private networks. It still works exactly the same way. Using a public IP inside your private network is a completely unnecessary waste of time.

[socratis]

Using a public IP inside your private network is a completely unnecessary waste of time.

Not to mention the confusion...

[SFLegion]

I know that, I will not have a public IP 203.2.2.1 with the setup I'm doing, and I know this specific IP address will not prove anything special about the NAT capability of my firewall, I know that if I do a bridged, or a NAT interface I will be able to change the default gateway.
But as I said I'm student, this is a work I was asked to do, I've been given a map of the network to create along with the IP address I'm supposed to use, and I want to stick to that.

I think we going out of the point here, my original question was if it was possible to change the defaut gateway of a NatNetwork ? If i cannot no problem I will use a another IP for my guess, and I know this will change nothing, but if it is possible I would like to know it.

Thanks.

[socratis]

if it was possible to change the defaut gateway of a NatNetwork

No. Assuming your NATnetwork is A.B.C.0/24 the gateway is going to be A.B.C.1.

But there was more to the original question. You said it was conflicting. That's why we keep telling you to avoid real IPs.