Can Network Security Groups (NSGs) deny outbound traffic to the internet?

Network Security Groups (NSGs) can indeed deny outbound traffic to the internet. NSGs are used in Azure to control inbound and outbound traffic to network interfaces, VMs, and subnets. They contain a list of rules that can explicitly allow or deny traffic based on specific conditions such as IP addresses, ports, and protocols.

When a rule is configured to deny outbound traffic, it effectively blocks any connections that match the rule. This allows for very granular control over the traffic flow from your resources in the Azure environment. Organizations can use NSGs to enforce security policies, limit exposure to the internet, and protect resources from unauthorized access or data exfiltration.

While NSGs can allow or deny traffic depending on how they are configured, they can clearly be set to deny specific outbound traffic to the internet, which is a key feature for maintaining secure network boundaries.