to manipulate and/or extend the scheme should expect to do a certain
level of code inspection.
-Vlib (Vector library) primary buffer metatdata
+Vlib (Vector library) primary buffer metadata
----------------------------------------------
The first 64 octets of each vlib_buffer_t carries the primary buffer
* NAT fields
* u32 unused[6]
-Vnet (network stack) secondary buffer metatdata
+Vnet (network stack) secondary buffer metadata
-----------------------------------------------
Vnet primary buffer metadata occupies space reserved in the vlib