A method implemented by a network element (NE) comprises receiving, by a receiver of the NE, an Internet Protocol (IP) version 4 (IPv4) packet from another NE, wherein the IPv4 packet comprises an IPv4 header, an extension header, and upper layer data, wherein the IPv4 header comprises a protocol number associated with the extension header, and wherein the IPv4 packet comprises a total length of the extension header, and processing, by a processor coupled to the receiver, the IPv4 packet based on the total length of the extension header.