Hi,

In openbsd there is a macro called DLT_LOOP. I guess there is something 
like it in netbsd.
DLT_LOOP is a datalink type. In openbsd its defined in /usr/src/sys/net/bpf.h
This way:

#define DLT_LOOP        12      /* loopback type (af header) */

DLT_LOOP is for loopback interface.
Anyone knows if there is the same for netbsd but named differently?
Bye,

Mipam (Reinoud).