The Community Edition of the excellent network simulation program EVE-NG supports running a variety of network nodes like ASAv, NX-OSv, CSR1000v, Arista vEOS, and so on. Use it to get ready for the RS switching, and currently use it to get ready for the  Datacenter exam.

No eve-ng cloud network is available to help connect devices to the Internet quickly take the example of creating a Linux image and adding it to EVE-NG before realizing you forgot to instal something. Links cannot be connected while the devices are running; you must turn them off first.

The Professional edition has both of these. Although the hot-add functionality appears to have already been added to the community edition, it appears that the creator of EVE-NG has chosen to fork the game and add other great features.. The best part is that it will be open source and free.

But because that time has not yet come, how to build a NAT cloud in the EVE-NG community version is there. In essence, this is a virtual network that has a DHCP server and NAT connections through the EVE-NG VM's management interface for Internet access.

Make a compact lab; all that is needed is a Linux node running a Debian image. Add a network next + icon at the top of the screen, then network, give it a name, and then choose the Cloud9 interface from the type dropdown.

When you do this, a tiny cloud symbol will appear in your lab topology, allowing you to connect the topology's nodes to the Internet. There is no restriction on the number of nodes you can connect, and there are an unlimited number of Ethernet connections available.

DHCP should be activated on all cloud-connected devices. Their address will be given to them through DHCP in the range of 192.168.255.10 to 192.168.255.240. You can set up some devices with static IP addresses if they can't or shouldn't get their addresses from DHCP. However, you should refrain from utilizing addresses in the DHCP range.