Packet filtering is performed to detect for and discard malformed data packets that would be discarded by a wireless network if received from a wireless device. A cdma2000 network may restart a PPP session upon receiving (1) malformed data packets with source IPv4 addresses different from IPv4 addresses (if any) assigned to the wireless device or (2) malformed data packets with source IPv6 addresses having prefixes different from prefixes (if any) associated with the PPP session. The wireless device may receive data packets from a terminal equipment coupled to the wireless device and/or applications running at the wireless device. The wireless device may filter these data packets with packet filters to detect for malformed data packets with invalid IPv4 addresses, invalid IPv6 address prefixes, and so on. The wireless device discards malformed data packets and sends the remaining data packets to the wireless network.