Question

Bob wants to allow devices at a branch office to query publicly available DNS servers from a large cloud provider. Which of the following ports should he open in the firewall in order to enable this?

Answer 1

In order to allow devices at a branch office to query publicly available DNS servers from a large cloud provider, Bob should open port 53 in the firewall.

DNS queries and responses are transmitted over UDP and TCP port 53, so opening this port in the firewall will enable the devices to communicate with the DNS servers.

Therefore, Bob should open port 53 in the firewall.