The <sys/netmgr.h> header defines the ND_LOCAL_NODE macro as zero. You can use it any time that you're dealing with node descriptors to make it obvious that you're talking about the local node.
As discussed, node descriptors represent machines, but they also include Quality of Service information. If you want to see if two node descriptors refer to the same machine, you can't just arithmetically compare the descriptors for equality; use the ND_NODE_CMP() macro instead:
This is similar to the way that strcmp() and memcmp() work. It's done this way in case you want to do any sorting that's based on node descriptors.
The <sys/netmgr.h> header file also defines the following networking functions: