1. A method of operating a computing device with network interfaces and a firewall, the firewall executing at least one filter, each filter being associated with a network interface of the network interfaces, and each filter, when executed, determining whether a network communication passes through the firewall, the method comprising: receiving a network-specific rule, the network-specific rule associated with a type of network to which the network-specific rule is applicable; storing a mapping, the mapping indicating network types associated with the network interfaces, wherein a given network type maps to multiple corresponding network interfaces of the given network type; translating the network-specific rule to interface-specific rules by identifying, according to the mapping and the network type identified by the network-specific rule, any of the network interfaces that have the network type, and for each of multiple identified network interfaces generating an interface-specific rule corresponding to the interface-specific rule; and filtering network traffic, by the firewall, according to the network-specific rules.