File 0021-dhcp-ip-family-symlinks.patch of Package dhcp

--- client/dhclient.c.orig
+++ client/dhclient.c
@@ -252,6 +252,17 @@ main(int argc, char **argv) {
 	progname = argv[0];
 #endif
 
+#ifdef DHCPv6
+	/* Support being called using `dhclient4` or `dhclient6` symlinks */
+	if (argv[0][strlen(argv[0]) - 1] == '4') {
+		local_family_set = 1;
+		local_family = AF_INET;
+	} else if (argv[0][strlen(argv[0]) - 1] == '6') {
+		local_family_set = 1;
+		local_family = AF_INET6;
+	}
+#endif /* DHCPv6 */
+
 	/* Initialize client globals. */
 	memset(&default_duid, 0, sizeof(default_duid));
 
--- relay/dhcrelay.c.orig
+++ relay/dhcrelay.c
@@ -237,6 +237,17 @@ main(int argc, char **argv) {
 	progname = argv[0];
 #endif
 
+#ifdef DHCPv6
+	/* Support being called using `dhcrelay4` or `dhcrelay6` symlinks */
+	if (argv[0][strlen(argv[0]) - 1] == '4') {
+		local_family_set = 1;
+		local_family = AF_INET;
+	} else if (argv[0][strlen(argv[0]) - 1] == '6') {
+		local_family_set = 1;
+		local_family = AF_INET6;
+	}
+#endif /* DHCPv6 */
+
 	/* Make sure that file descriptors 0(stdin), 1,(stdout), and
 	   2(stderr) are open. To do this, we assume that when we
 	   open a file the lowest available file descriptor is used. */
--- server/dhcpd.c.orig
+++ server/dhcpd.c
@@ -260,6 +260,17 @@ main(int argc, char **argv) {
 	progname = argv[0];
 #endif
 
+#ifdef DHCPv6
+	/* Support being called using `dhcpd4` or `dhcpd6` symlinks */
+	if (argv[0][strlen(argv[0]) - 1] == '4') {
+		local_family_set = 1;
+		local_family = AF_INET;
+	} else if (argv[0][strlen(argv[0]) - 1] == '6') {
+		local_family_set = 1;
+		local_family = AF_INET6;
+	}
+#endif /* DHCPv6 */
+
         /* Make sure that file descriptors 0 (stdin), 1, (stdout), and
            2 (stderr) are open. To do this, we assume that when we
            open a file the lowest available file descriptor is used. */