Disclosed are various embodiments for time based network addresses. A network packet is received over a network by a first computing device from a second computing device. The network packet contains a time-dependent destination address for a third computing device, such as a time-dependent internet protocol version 6 (IPv6) address. The time-dependent destination address contains a time-dependent checksum based at least in part on a current time and an encryption key associated with the third computing device. The checksum is validated upon receipt. In response to a determination that the checksum is valid, the network packet is forwarded to the third computing device.