The problem actually goes back to ancient releases of BSD.  I looked
back to 4.2BSD, and the problem exists there.

Consider the following two entries in /etc/networks:

	test1	10
	test2	11	alias2
	test3	12	# hi there

On Solaris getnetbyname (and getnetent), we treat "test1", "test2",
and "test3" as the real network names, and "alias2" as an alias for
just network "test2."  This appears to be fairly reasonable.

On BSD, it interprets the second entry the same way we do -- network
"test2", single alias "alias2", and "test3" with no aliases.  However,
it *intentionally* treats the first case differently.  On BSD, that's
interpreted as network "test1" with alias "10".

The offending lines in /usr/src/lib/libc/net/getnetbyht.c are:

	p = strpbrk(cp, " \t");
	if (p != NULL)
		*p++ = '\0';
	net.n_net = inet_network(cp);
	net.n_addrtype = AF_INET;
	q = net.n_aliases = net_aliases;
	if (p != NULL) 
--->		cp = p;

This sets the initial pointer to the next character after the first
blank following the network number.  If there is no such character,
then this is NULL, and we just fall through with cp set to the start
of the network number.

Fix: 

Remove the "if (p != NULL)" line.
How-To-Repeat: #include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

int
main(int argc, char **argv)
{
	struct netent *np;
	unsigned char *cp;
	unsigned long ina;
	char **cpp;

	np = getnetbyname(argv[1]);
	if (np == NULL) {
		printf("getnetbyname: NULL\n");
	} else {
		cp = (unsigned char *)&np->n_net;
		printf("getnetbyname: %d %d %d %d '%s'\n", cp[0], cp[1], cp[2],
		    cp[3], np->n_name);
		if (*np->n_aliases != NULL) {
			printf("     aliases:");
			for (cpp = np->n_aliases; *cpp != NULL; cpp++)
				printf(" '%s'", *cpp);
			putchar('\n');
		}
	}
	ina = inet_network(argv[1]);
	cp = (unsigned char *)&ina;
	printf("inet_network: %d %d %d %d\n", cp[0], cp[1], cp[2],
	    cp[3]);
	return 0;
}