Disclosed are systems and methods for firewall configuration. A request can be transmitted to a DNS server. A response to the DNS request can include an Internet Protocol (IP) address. A firewall rule can be generated permitting access to the IP address. The firewall rule can be configured to be valid until expiration of a time-to-live value in the response to the DNS request. Thus, firewall rules can be automatically created as needed by executed processes, eliminating the need for manual firewall rule creation. As the firewall rule is invalid after the expiration of the time-to-live value, risks associated with maintaining out-of-date firewall rules are eliminated, as is the requirement to manually remove or modify out-of-date firewall rules.