editcap -T 101 broken_type276.pcap fixed_rawip.pcap If the original data was Linux SLL (Type 113):

In many recent implementations, corresponds to DLT_IPNET (used for Juniper Networks internal encapsulation) or a proprietary radio header. However, the most common source of this error in the open-source community is captures from Bluetooth , ZigBee (802.15.4) , or User-Defined DLTs created by specialized hardware (like GPS receivers or custom FPGA network cards).

Or perhaps a variant: pcap_open_offline: network type 276 unknown or unsupported

You run a command—perhaps a custom tcpdump filter, a tcpslice extraction, or a specialized fuzzer—and the terminal spits out: