Methods, systems, and media for adding IP addresses to firewalls are provided. In some embodiments, the method comprises: receiving a network packet that includes an external IP address associated with an external device, wherein the external device is a device not protected by a firewall; determining whether the external IP address is included in a group of IP addresses maintained by the firewall; determining whether to add the external IP address to the group of IP addresses; identifying an Internet Service Provider (ISP) associated with the external IP address; determining whether the ISP is included in a group of ISPs maintained by the firewall; and in response to determining that the ISP is not included in the group of ISPs maintained by the firewall, adding the external IP address to the group of IP addresses and adding the ISP to the group of ISPs.