## Isolated Network The basic building block of the Atlas Cloud is the Isolated network. It's easy to think of it as analogous to a simple flat home network. The Isolated network is an excellent entry point into the Atlas cloud as it gives you a simple way to start building smaller cloud services. For larger deployments you may want to consider using [[VPC]] networks instead to have better segregation and finer control over your infrastructure. When you commission an Isolated network by clicking the "Add Network" button you get a simple network with a NAT gateway attached to it. After creating an Isolated Network you can click your network to configure it. The network should have a public IP address attached to it that acts as the NAT gateway. You can configure egress rules under the "Egress rules" tab. ![[Pasted image 20251002222730.png]] ### Egress Rules By default, outbound traffic from the network may be blocked. You need to configure egress rules to allow your instances to reach the internet. Common egress rules to add: - TCP port 80 to `0.0.0.0/0` (HTTP, for package downloads) - TCP port 443 to `0.0.0.0/0` (HTTPS, for secure downloads and APIs) - UDP port 53 to `0.0.0.0/0` (DNS resolution) - TCP port 53 to `0.0.0.0/0` (DNS resolution) Without these rules, instances cannot run `apt update`, resolve domain names, or fetch external resources like SSL certificates. The isolated network also creates a Virtual Router that handles DHCP in the network. See [[Public IP Addresses]] for information on how to configure the Firewall and port forwarding. ## L2 Network Those are not supported in the Atlas Cloud ## Shared Network Those are not supported in the Atlas Cloud yet. This feature is under development.