Ipdecap can decapsulate traffic encapsulated within GRE, IPIP, 6in4, and ESP (IPSEC) protocols, and can also remove IEEE 802.1Q (virtual LAN) headers.
It reads packets from a pcap file, removes the encapsulation protocol, and writes them in another pcap file.
pppoesk is a small program that can terminate
bogus PPPoE sessions by sending a forged PADT
(terminate) packet to the ISP equipment. PPPoE is
used in DSL connections to establish a link
between you and your DSL provider.