1. A computer-implemented security system, comprising: a set of security profiles that provides communications security for a multi-homed device, each of the security profiles including a set of rules that constrains device connectivity according to that profile, the security profiles being associated with connections from which data packets are being received, the set of security profiles comprising a first security profile being constrained to apply to a first address range for all traffic from a first active connection, and a second security profile being constrained to apply to a second address range for all traffic from a second concurrently active connection, the first security profile being different from the second security profile such that the first security profile does not affect security of the second concurrently active connection and the second security profile does not affect security of the first active connection; and a security component for determining if the connections are active by examining the data packets received, and responsive to determining that one or more of the connections is active automatically selecting and applying corresponding security profiles to the one or more active connections.