diff --git a/config.c b/config.c
index 9ef8be1..d3c19e5 100644
--- a/config.c
+++ b/config.c
@@ -34,6 +34,116 @@ enum config_section {
 	UNKNOWN_SECTION,
 };
 
+enum config_type {
+	CFG_TYPE_INT,
+	CFG_TYPE_DOUBLE,
+};
+
+typedef union {
+	int i;
+	double d;
+} any_t;
+
+#define CONFIG_LABEL_SIZE 32
+
+#define CFG_ITEM_STATIC (1 << 0) /* statically allocated, not to be freed */
+#define CFG_ITEM_LOCKED (1 << 1) /* command line value, may not be changed */
+#define CFG_ITEM_PORT   (1 << 2) /* item may appear in port sections */
+
+struct config_item {
+	char label[CONFIG_LABEL_SIZE];
+	enum config_type type;
+	unsigned int flags;
+	any_t val;
+	any_t min;
+	any_t max;
+};
+
+#define N_CONFIG_ITEMS (sizeof(config_tab) / sizeof(config_tab[0]))
+
+#define CONFIG_ITEM_INT(_label, _port, _default, _min, _max) {	\
+	.label	= _label,				\
+	.type	= CFG_TYPE_INT,				\
+	.flags	= _port ? CFG_ITEM_PORT : 0,		\
+	.val.i	= _default,				\
+	.min.i	= _min,					\
+	.max.i	= _max,					\
+}
+
+#define GLOB_ITEM_INT(label, _default, min, max) \
+	CONFIG_ITEM_INT(label, 0, _default, min, max)
+
+#define PORT_ITEM_INT(label, _default, min, max) \
+	CONFIG_ITEM_INT(label, 1, _default, min, max)
+
+struct config_item config_tab[] = {
+	PORT_ITEM_INT("udp_ttl", 1, 1, 255),
+};
+
+static struct config_item *config_section_item(struct config *cfg,
+					       const char *section,
+					       const char *name)
+{
+	char buf[CONFIG_LABEL_SIZE + MAX_IFNAME_SIZE];
+
+	snprintf(buf, sizeof(buf), "%s.%s", section, name);
+	return hash_lookup(cfg->htab, buf);
+}
+
+static struct config_item *config_global_item(struct config *cfg,
+					      const char *name)
+{
+	return config_section_item(cfg, "global", name);
+}
+
+static struct config_item *config_find_item(struct config *cfg,
+					    const char *section,
+					    const char *name)
+{
+	struct config_item *ci;
+	if (section) {
+		ci = config_section_item(cfg, section, name);
+		if (ci) {
+			return ci;
+		}
+	}
+	return config_global_item(cfg, name);
+}
+
+static struct config_item *config_item_alloc(struct config *cfg,
+					     const char *section,
+					     const char *name,
+					     enum config_type type)
+{
+	struct config_item *ci;
+	char buf[CONFIG_LABEL_SIZE + MAX_IFNAME_SIZE];
+
+	ci = calloc(1, sizeof(*ci));
+	if (!ci) {
+		fprintf(stderr, "low memory\n");
+		return NULL;
+	}
+	strncpy(ci->label, name, CONFIG_LABEL_SIZE - 1);
+	ci->type = type;
+
+	snprintf(buf, sizeof(buf), "%s.%s", section, ci->label);
+	if (hash_insert(cfg->htab, buf, ci)) {
+		fprintf(stderr, "low memory or duplicate item %s\n", name);
+		free(ci);
+		return NULL;
+	}
+
+	return ci;
+}
+
+static void config_item_free(void *ptr)
+{
+	struct config_item *ci = ptr;
+	if (ci->flags & CFG_ITEM_STATIC)
+		return;
+	free(ci);
+}
+
 static enum parser_result parse_section_line(char *s, enum config_section *section)
 {
 	if (!strcasecmp(s, "[global]")) {
@@ -52,6 +162,65 @@ static enum parser_result parse_section_line(char *s, enum config_section *secti
 	return PARSED_OK;
 }
 
+static enum parser_result parse_item(struct config *cfg,
+				     const char *section,
+				     const char *option,
+				     const char *value)
+{
+	struct config_item *cgi, *dst;
+	enum parser_result r = BAD_VALUE;
+	double df;
+	int val;
+
+	/* If there is no default value, then the option is bogus. */
+	cgi = config_global_item(cfg, option);
+	if (!cgi) {
+		return NOT_PARSED;
+	}
+
+	switch (cgi->type) {
+	case CFG_TYPE_INT:
+		r = get_ranged_int(value, &val, cgi->min.i, cgi->max.i);
+		break;
+	case CFG_TYPE_DOUBLE:
+		r = get_ranged_double(value, &df, cgi->min.d, cgi->max.d);
+		break;
+	}
+	if (r != PARSED_OK) {
+		return r;
+	}
+
+	if (section) {
+		if (!(cgi->flags & CFG_ITEM_PORT)) {
+			return NOT_PARSED;
+		}
+		/* Create or update this port specific item. */
+		dst = config_section_item(cfg, section, option);
+		if (!dst) {
+			dst = config_item_alloc(cfg, section, option, cgi->type);
+			if (!dst) {
+				return NOT_PARSED;
+			}
+		}
+	} else if (cgi->flags & CFG_ITEM_LOCKED) {
+		/* This global option was set on the command line. */
+		return PARSED_OK;
+	} else {
+		/* Update the global default value. */
+		dst = cgi;
+	}
+
+	switch (dst->type) {
+	case CFG_TYPE_INT:
+		dst->val.i = val;
+		break;
+	case CFG_TYPE_DOUBLE:
+		dst->val.d = df;
+		break;
+	}
+	return PARSED_OK;
+}
+
 static enum parser_result parse_pod_setting(const char *option,
 					    const char *value,
 					    struct port_defaults *pod)
@@ -173,9 +342,10 @@ static enum parser_result parse_pod_setting(const char *option,
 	return PARSED_OK;
 }
 
-static enum parser_result parse_port_setting(const char *option,
-					    const char *value,
-					    struct interface *iface)
+static enum parser_result parse_port_setting(struct config *cfg,
+					     const char *option,
+					     const char *value,
+					     struct interface *iface)
 {
 	enum parser_result r;
 	int val;
@@ -237,7 +407,7 @@ static enum parser_result parse_port_setting(const char *option,
 		iface->boundary_clock_jbod = val;
 
 	} else
-		return NOT_PARSED;
+		return parse_item(cfg, iface->name, option, value);
 
 	return PARSED_OK;
 }
@@ -614,7 +784,7 @@ static enum parser_result parse_global_setting(const char *option,
 		cfg->dds.boundary_clock_jbod = val;
 
 	} else
-		return NOT_PARSED;
+		return parse_item(cfg, NULL, option, value);
 
 	return PARSED_OK;
 }
@@ -727,7 +897,7 @@ int config_read(char *name, struct config *cfg)
 			if (current_section == GLOBAL_SECTION)
 				parser_res = parse_global_setting(option, value, cfg);
 			else
-				parser_res = parse_port_setting(option, value, current_port);
+				parser_res = parse_port_setting(cfg, option, value, current_port);
 
 			switch (parser_res) {
 			case PARSED_OK:
@@ -806,11 +976,40 @@ void config_init_interface(struct interface *iface, struct config *cfg)
 
 int config_init(struct config *cfg)
 {
+	char buf[CONFIG_LABEL_SIZE + 8];
+	struct config_item *ci;
+	int i;
+
 	cfg->htab = hash_create();
 	if (!cfg->htab) {
 		return -1;
 	}
+
+	/* Populate the hash table with global defaults. */
+	for (i = 0; i < N_CONFIG_ITEMS; i++) {
+		ci = &config_tab[i];
+		ci->flags |= CFG_ITEM_STATIC;
+		snprintf(buf, sizeof(buf), "global.%s", ci->label);
+		if (hash_insert(cfg->htab, buf, ci)) {
+			fprintf(stderr, "duplicate item %s\n", ci->label);
+			goto fail;
+		}
+	}
+
+	/* Perform a Built In Self Test.*/
+	for (i = 0; i < N_CONFIG_ITEMS; i++) {
+		ci = &config_tab[i];
+		ci = config_global_item(cfg, ci->label);
+		if (ci != &config_tab[i]) {
+			fprintf(stderr, "config BIST failed at %s\n",
+				config_tab[i].label);
+			goto fail;
+		}
+	}
 	return 0;
+fail:
+	hash_destroy(cfg->htab, NULL);
+	return -1;
 }
 
 void config_destroy(struct config *cfg)
@@ -821,5 +1020,37 @@ void config_destroy(struct config *cfg)
 		STAILQ_REMOVE_HEAD(&cfg->interfaces, list);
 		free(iface);
 	}
-	hash_destroy(cfg->htab, free);
+	hash_destroy(cfg->htab, config_item_free);
+}
+
+double config_get_double(struct config *cfg, const char *section,
+			 const char *option)
+{
+	struct config_item *ci = config_find_item(cfg, section, option);
+
+	if (!ci || ci->type != CFG_TYPE_DOUBLE) {
+		pr_err("bug: config option %s missing or invalid!", option);
+		exit(-1);
+	}
+	pr_debug("config item %s.%s is %f", section, option, ci->val.d);
+	return ci->val.d;
+}
+
+int config_get_int(struct config *cfg, const char *section, const char *option)
+{
+	struct config_item *ci = config_find_item(cfg, section, option);
+
+	if (!ci) {
+		pr_err("bug: config option %s missing!", option);
+		exit(-1);
+	}
+	switch (ci->type) {
+	case CFG_TYPE_DOUBLE:
+		pr_err("bug: config option %s type mismatch!", option);
+		exit(-1);
+	case CFG_TYPE_INT:
+		break;
+	}
+	pr_debug("config item %s.%s is %d", section, option, ci->val.i);
+	return ci->val.i;
 }
diff --git a/config.h b/config.h
index 222883a..f722ea6 100644
--- a/config.h
+++ b/config.h
@@ -105,4 +105,14 @@ struct interface *config_create_interface(char *name, struct config *cfg);
 void config_init_interface(struct interface *iface, struct config *cfg);
 void config_destroy(struct config *cfg);
 
+/* New, hash table based methods: */
+
+int config_init(struct config *cfg);
+
+double config_get_double(struct config *cfg, const char *section,
+			 const char *option);
+
+int config_get_int(struct config *cfg, const char *section,
+		   const char *option);
+
 #endif
diff --git a/makefile b/makefile
index 922769b..bcdbb92 100644
--- a/makefile
+++ b/makefile
@@ -46,13 +46,13 @@ all: $(PRG)
 
 ptp4l: $(OBJ)
 
-pmc: msg.o pmc.o pmc_common.o print.o raw.o sk.o tlv.o transport.o udp.o \
- udp6.o uds.o util.o version.o
-
-phc2sys: clockadj.o clockcheck.o linreg.o msg.o ntpshm.o nullf.o phc.o \
- phc2sys.o pi.o pmc_common.o print.o raw.o servo.o sk.o stats.o sysoff.o tlv.o \
+pmc: config.o hash.o msg.o pmc.o pmc_common.o print.o raw.o sk.o tlv.o \
  transport.o udp.o udp6.o uds.o util.o version.o
 
+phc2sys: clockadj.o clockcheck.o config.o hash.o linreg.o msg.o ntpshm.o \
+ nullf.o phc.o phc2sys.o pi.o pmc_common.o print.o raw.o servo.o sk.o stats.o \
+ sysoff.o tlv.o transport.o udp.o udp6.o uds.o util.o version.o
+
 hwstamp_ctl: hwstamp_ctl.o version.o
 
 phc_ctl: phc_ctl.o phc.o sk.o util.o clockadj.o sysoff.o print.o version.o
diff --git a/phc2sys.c b/phc2sys.c
index 5ba99c3..92af7ad 100644
--- a/phc2sys.c
+++ b/phc2sys.c
@@ -1236,6 +1236,10 @@ int main(int argc, char *argv[])
 
 	handle_term_signals();
 
+	if (config_init(&phc2sys_config)) {
+		return -1;
+	}
+
 	configured_pi_kp = KP;
 	configured_pi_ki = KI;
 
diff --git a/pmc.c b/pmc.c
index 1fe8183..b5cfd4c 100644
--- a/pmc.c
+++ b/pmc.c
@@ -739,11 +739,16 @@ int main(int argc, char *argv[])
 	enum transport_type transport_type = TRANS_UDP_IPV4;
 	UInteger8 boundary_hops = 1, domain_number = 0, transport_specific = 0;
 	struct ptp_message *msg;
+	struct config *cfg = &pmc_config;
 #define N_FD 2
 	struct pollfd pollfd[N_FD];
 
 	handle_term_signals();
 
+	if (config_init(&pmc_config)) {
+		return -1;
+	}
+
 	/* Process the command line arguments. */
 	progname = strrchr(argv[0], '/');
 	progname = progname ? 1+progname : argv[0];
@@ -774,6 +779,7 @@ int main(int argc, char *argv[])
 			if (strlen(optarg) > MAX_IFNAME_SIZE) {
 				fprintf(stderr, "path %s too long, max is %d\n",
 					optarg, MAX_IFNAME_SIZE);
+				config_destroy(cfg);
 				return -1;
 			}
 			strncpy(uds_path, optarg, MAX_IFNAME_SIZE);
@@ -784,18 +790,19 @@ int main(int argc, char *argv[])
 			break;
 		case 'v':
 			version_show(stdout);
+			config_destroy(cfg);
 			return 0;
 		case 'z':
 			zero_datalen = 1;
 			break;
 		case 'h':
 			usage(progname);
+			config_destroy(cfg);
 			return 0;
 		case '?':
-			usage(progname);
-			return -1;
 		default:
 			usage(progname);
+			config_destroy(cfg);
 			return -1;
 		}
 	}
@@ -821,6 +828,7 @@ int main(int argc, char *argv[])
 			 domain_number, transport_specific, zero_datalen);
 	if (!pmc) {
 		fprintf(stderr, "failed to create pmc\n");
+		config_destroy(cfg);
 		return -1;
 	}
 
@@ -896,5 +904,6 @@ int main(int argc, char *argv[])
 
 	pmc_destroy(pmc);
 	msg_cleanup();
+	config_destroy(cfg);
 	return ret;
 }
diff --git a/ptp4l.c b/ptp4l.c
index 56cb8bd..e2482c8 100644
--- a/ptp4l.c
+++ b/ptp4l.c
@@ -182,6 +182,10 @@ int main(int argc, char *argv[])
 	if (handle_term_signals())
 		return -1;
 
+	if (config_init(&cfg_settings)) {
+		return -1;
+	}
+
 	/* Set fault timeouts to a default value */
 	for (i = 0; i < FT_CNT; i++) {
 		cfg_settings.pod.flt_interval_pertype[i].type = FTMO_LOG2_SECONDS;