diff --git a/src/common.c b/src/common.c
index 03bb33c1..0b56e9f4 100644
--- a/src/common.c
+++ b/src/common.c
@@ -217,13 +217,21 @@ is_root_local(void)
 }
 
 uint32_t
-lifetime_left(uint32_t lifetime, const struct timespec *acquired, const struct timespec *now)
+lifetime_left(uint32_t lifetime, const struct timespec *acquired, struct timespec *now)
 {
 	uint32_t elapsed;
+	struct timespec n;
 
 	if (lifetime == INFINITE_LIFETIME)
 		return lifetime;
 
+	if (now == NULL) {
+		timespecclear(&n);
+		now = &n;
+	}
+	if (!timespecisset(now))
+		clock_gettime(CLOCK_MONOTONIC, now);
+
 	elapsed = (uint32_t)eloop_timespec_diff(now, acquired, NULL);
 	if (elapsed > lifetime)
 		return 0;
diff --git a/src/common.h b/src/common.h
index 096f6bd4..a2ab05ea 100644
--- a/src/common.h
+++ b/src/common.h
@@ -150,5 +150,5 @@ ssize_t writefile(const char *, mode_t, const void *, size_t);
 int filemtime(const char *, time_t *);
 char *get_line(char ** __restrict, ssize_t * __restrict);
 int is_root_local(void);
-uint32_t lifetime_left(uint32_t, const struct timespec *, const struct timespec *);
+uint32_t lifetime_left(uint32_t, const struct timespec *, struct timespec *);
 #endif
diff --git a/src/dhcp.c b/src/dhcp.c
index 9e23ab62..bc87c760 100644
--- a/src/dhcp.c
+++ b/src/dhcp.c
@@ -809,7 +809,6 @@ make_message(struct bootp **bootpm, const struct interface *ifp, uint8_t type)
 	const struct dhcp_lease *lease = &state->lease;
 	char hbuf[HOSTNAME_MAX_LEN + 1];
 	const char *hostname;
-	const struct vivco *vivco;
 	int mtu;
 #ifdef AUTH
 	uint8_t *auth, auth_len;
@@ -1138,35 +1137,35 @@ make_message(struct bootp **bootpm, const struct interface *ifp, uint8_t type)
 		       p += ifo->mudurl[0] + 1;
 		}
 
+#ifndef SMALL
 		if (ifo->vivco_len &&
 		    !has_option_mask(ifo->nomask, DHO_VIVCO))
 		{
-			AREA_CHECK(sizeof(ul));
-			*p++ = DHO_VIVCO;
-			lp = p++;
-			*lp = sizeof(ul);
-			ul = htonl(ifo->vivco_en);
-			memcpy(p, &ul, sizeof(ul));
-			p += sizeof(ul);
-			for (i = 0, vivco = ifo->vivco;
-			    i < ifo->vivco_len;
-			    i++, vivco++)
-			{
-				AREA_FIT(vivco->len);
-				if (vivco->len + 2 + *lp > 255) {
-					logerrx("%s: VIVCO option too big",
-					    ifp->name);
-					free(bootp);
-					return -1;
-				}
-				*p++ = (uint8_t)vivco->len;
-				memcpy(p, vivco->data, vivco->len);
-				p += vivco->len;
+			struct vivco *vivco = ifo->vivco;
+			size_t vlen = ifo->vivco_len;
+			struct rfc3396_ctx rctx = {
+				.code = DHO_VIVCO,
+				.buf = &p,
+				.buflen = AREA_LEFT,
+			};
+
+			for (; vlen > 0; vivco++, vlen--) {
+				ul = htonl(vivco->en);
+				if (rfc3396_write(&rctx, &ul, sizeof(ul)) == -1)
+					goto toobig;
+				lp = rfc3396_zero(&rctx);
+				if (lp == NULL)
+					goto toobig;
+				if (rfc3396_write_byte(&rctx,
+				    (uint8_t)vivco->len) == -1)
+					goto toobig;
+				if (rfc3396_write(&rctx,
+				    vivco->data, vivco->len) == -1)
+					goto toobig;
 				*lp = (uint8_t)(*lp + vivco->len + 1);
 			}
 		}
-
-#ifndef SMALL
+		
 		if (ifo->vsio_len &&
 		    !has_option_mask(ifo->nomask, DHO_VIVSO))
 		{
diff --git a/src/dhcp6.c b/src/dhcp6.c
index ca076e4e..ea0bff53 100644
--- a/src/dhcp6.c
+++ b/src/dhcp6.c
@@ -276,29 +276,28 @@ dhcp6_makeuser(void *data, const struct interface *ifp)
 	return sizeof(o) + olen;
 }
 
+#ifndef SMALL
+/* DHCPv6 Option 16 (Vendor Class Option) */
 static size_t
 dhcp6_makevendor(void *data, const struct interface *ifp)
 {
 	const struct if_options *ifo;
-	size_t len, vlen, i;
+	size_t len = 0, optlen, vlen, i;
 	uint8_t *p;
 	const struct vivco *vivco;
 	struct dhcp6_option o;
 
 	ifo = ifp->options;
-	len = sizeof(uint32_t); /* IANA PEN */
-	if (ifo->vivco_en) {
-		vlen = 0;
+	if (ifo->vivco_len > 0) {
 		for (i = 0, vivco = ifo->vivco;
 		    i < ifo->vivco_len;
 		    i++, vivco++)
-			vlen += sizeof(uint16_t) + vivco->len;
-		len += vlen;
+			len += sizeof(o) + sizeof(uint32_t) + sizeof(uint16_t) + vivco->len;
 	} else if (ifo->vendorclassid[0] != '\0') {
 		/* dhcpcd owns DHCPCD_IANA_PEN.
 		 * If you need your own string, get your own IANA PEN. */
 		vlen = strlen(ifp->ctx->vendor);
-		len += sizeof(uint16_t) + vlen;
+		len += sizeof(o) + sizeof(uint32_t) + sizeof(uint16_t) + vlen;
 	} else
 		return 0;
 
@@ -312,19 +311,19 @@ dhcp6_makevendor(void *data, const struct interface *ifp)
 		uint16_t hvlen;
 
 		p = data;
-		o.code = htons(D6_OPTION_VENDOR_CLASS);
-		o.len = htons((uint16_t)len);
-		memcpy(p, &o, sizeof(o));
-		p += sizeof(o);
-		pen = htonl(ifo->vivco_en ? ifo->vivco_en : DHCPCD_IANA_PEN);
-		memcpy(p, &pen, sizeof(pen));
-		p += sizeof(pen);
 
-		if (ifo->vivco_en) {
+		if (ifo->vivco_len > 0) {
 			for (i = 0, vivco = ifo->vivco;
 			    i < ifo->vivco_len;
-			    i++, vivco++)
-			{
+			    i++, vivco++) {
+				optlen = sizeof(uint32_t) + sizeof(uint16_t) + vivco->len;
+				o.code = htons(D6_OPTION_VENDOR_CLASS);
+				o.len = htons((uint16_t)optlen);
+				memcpy(p, &o, sizeof(o));
+				p += sizeof(o);
+				pen = htonl(vivco->en);
+				memcpy(p, &pen, sizeof(pen));
+				p += sizeof(pen);
 				hvlen = htons((uint16_t)vivco->len);
 				memcpy(p, &hvlen, sizeof(hvlen));
 				p += sizeof(hvlen);
@@ -332,17 +331,22 @@ dhcp6_makevendor(void *data, const struct interface *ifp)
 				p += vivco->len;
 			}
 		} else if (ifo->vendorclassid[0] != '\0') {
+			o.code = htons(D6_OPTION_VENDOR_CLASS);
+			o.len = htons((uint16_t)len);
+			memcpy(p, &o, sizeof(o));
+			p += sizeof(o);
+			pen = htonl(DHCPCD_IANA_PEN);
+			memcpy(p, &pen, sizeof(pen));
+			p += sizeof(pen);
 			hvlen = htons((uint16_t)vlen);
 			memcpy(p, &hvlen, sizeof(hvlen));
 			p += sizeof(hvlen);
 			memcpy(p, ifp->ctx->vendor, vlen);
 		}
 	}
-
-	return sizeof(o) + len;
+	return len;
 }
 
-#ifndef SMALL
 /* DHCPv6 Option 17 (Vendor-Specific Information Option) */
 static size_t
 dhcp6_makevendoropts(void *data, const struct interface *ifp)
@@ -875,10 +879,10 @@ dhcp6_makemessage(struct interface *ifp)
 
 	if (!has_option_mask(ifo->nomask6, D6_OPTION_USER_CLASS))
 		len += dhcp6_makeuser(NULL, ifp);
-	if (!has_option_mask(ifo->nomask6, D6_OPTION_VENDOR_CLASS))
-		len += dhcp6_makevendor(NULL, ifp);
 
 #ifndef SMALL
+	if (!has_option_mask(ifo->nomask6, D6_OPTION_VENDOR_CLASS))
+		len += dhcp6_makevendor(NULL, ifp);
 	if (!has_option_mask(ifo->nomask6, D6_OPTION_VENDOR_OPTS))
 		len += dhcp6_makevendoropts(NULL, ifp);
 #endif
@@ -1199,10 +1203,10 @@ dhcp6_makemessage(struct interface *ifp)
 
 	if (!has_option_mask(ifo->nomask6, D6_OPTION_USER_CLASS))
 		p += dhcp6_makeuser(p, ifp);
-	if (!has_option_mask(ifo->nomask6, D6_OPTION_VENDOR_CLASS))
-		p += dhcp6_makevendor(p, ifp);
 
 #ifndef SMALL
+	if (!has_option_mask(ifo->nomask6, D6_OPTION_VENDOR_CLASS))
+		p += dhcp6_makevendor(p, ifp);
 	if (!has_option_mask(ifo->nomask6, D6_OPTION_VENDOR_OPTS))
 		p += dhcp6_makevendoropts(p, ifp);
 #endif
diff --git a/src/eloop.c b/src/eloop.c
index 523455d7..d602fdcf 100644
--- a/src/eloop.c
+++ b/src/eloop.c
@@ -464,7 +464,7 @@ eloop_timespec_diff(const struct timespec *tsp, const struct timespec *usp,
 	unsigned long long tsecs, usecs, secs;
 	long nsecs;
 
-	if (tsp->tv_sec < 0) /* time wreapped */
+	if (tsp->tv_sec < 0) /* time wrapped */
 		tsecs = UTIME_MAX - (unsigned long long)(-tsp->tv_sec);
 	else
 		tsecs = (unsigned long long)tsp->tv_sec;
diff --git a/src/if-bsd.c b/src/if-bsd.c
index 68303e82..5b4c43a0 100644
--- a/src/if-bsd.c
+++ b/src/if-bsd.c
@@ -742,15 +742,12 @@ if_route(unsigned char cmd, const struct rt *rt)
 		{
 			rtm->rtm_index = (unsigned short)rt->rt_ifp->index;
 /*
- * OpenBSD rejects the message for on-link routes.
- * FreeBSD-12 kernel apparently panics.
- * I can't replicate the panic, but better safe than sorry!
- * https://roy.marples.name/archives/dhcpcd-discuss/0002286.html
- *
- * Neither OS currently allows IPv6 address sharing anyway, so let's
- * try to encourage someone to fix that by logging a waring during compile.
+ * OpenBSD rejects this for on-link routes when there is no default route
+ * OpenBSD does not allow the same IPv6 address on different
+ * interfaces on the same network, so let's try to encourage someone to
+ * fix that by logging a waring during compile.
  */
-#if defined(__FreeBSD__) || defined(__OpenBSD__)
+#ifdef __OpenBSD__
 #warning kernel does not allow IPv6 address sharing
 			if (!gateway_unspec || rt->rt_dest.sa_family!=AF_INET6)
 #endif
diff --git a/src/if-options.c b/src/if-options.c
index c50f65a1..54ae590b 100644
--- a/src/if-options.c
+++ b/src/if-options.c
@@ -656,6 +656,7 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
 	struct dhcp_opt **dop, *ndop;
 	size_t *dop_len, dl, odl;
 	struct vivco *vivco;
+	const struct vivco *vivco_endp = ifo->vivco + ifo->vivco_len;
 	struct group *grp;
 #ifdef AUTH
 	struct token *token;
@@ -2111,6 +2112,10 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
 		break;
 	case O_VENDCLASS:
 		ARG_REQUIRED;
+#ifdef SMALL
+			logwarnx("%s: vendor options not compiled in", ifname);
+			return -1;
+#else
 		fp = strwhite(arg);
 		if (fp)
 			*fp++ = '\0';
@@ -2119,6 +2124,12 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
 			logerrx("invalid code: %s", arg);
 			return -1;
 		}
+		for (vivco = ifo->vivco; vivco != vivco_endp; vivco++) {
+			if (vivco->en == (uint32_t)u) {
+				logerrx("vendor class option for enterprise number %u already defined", vivco->en);
+				return -1;
+			}
+		}
 		fp = strskipwhite(fp);
 		if (fp) {
 			s = parse_string(NULL, 0, fp);
@@ -2149,11 +2160,12 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
 			return -1;
 		}
 		ifo->vivco = vivco;
-		ifo->vivco_en = (uint32_t)u;
 		vivco = &ifo->vivco[ifo->vivco_len++];
+		vivco->en = (uint32_t)u;
 		vivco->len = dl;
 		vivco->data = (uint8_t *)np;
 		break;
+#endif
 	case O_AUTHPROTOCOL:
 		ARG_REQUIRED;
 #ifdef AUTH
@@ -2994,12 +3006,12 @@ free_options(struct dhcpcd_ctx *ctx, struct if_options *ifo)
 	    opt++, ifo->dhcp6_override_len--)
 		free_dhcp_opt_embenc(opt);
 	free(ifo->dhcp6_override);
+#ifndef SMALL
 	for (vo = ifo->vivco;
 	    ifo->vivco_len > 0;
 	    vo++, ifo->vivco_len--)
 		free(vo->data);
 	free(ifo->vivco);
-#ifndef SMALL
 	for (vsio = ifo->vsio;
 	    ifo->vsio_len > 0;
 	    vsio++, ifo->vsio_len--)
diff --git a/src/if-options.h b/src/if-options.h
index f3b9c17a..c892e75d 100644
--- a/src/if-options.h
+++ b/src/if-options.h
@@ -61,7 +61,6 @@
 #define USERCLASS_MAX_LEN	255
 #define VENDOR_MAX_LEN		255
 #define	MUDURL_MAX_LEN		255
-#define ENTERPRISE_NUMS_MAX_LEN	255
 
 #define DHCPCD_ARP			(1ULL << 0)
 #define DHCPCD_RELEASE			(1ULL << 1)
@@ -220,12 +219,12 @@ struct if_ia {
 #endif
 };
 
+#ifndef SMALL
 struct vivco {
+	uint32_t en;
 	size_t len;
 	uint8_t *data;
 };
-
-#ifndef SMALL
 struct vsio_so {
 	uint16_t opt;
 	uint16_t len;
@@ -303,13 +302,12 @@ struct if_options {
 	size_t nd_override_len;
 	struct dhcp_opt *dhcp6_override;
 	size_t dhcp6_override_len;
-	uint32_t vivco_en;
-	struct vivco *vivco;
-	size_t vivco_len;
 	struct dhcp_opt *vivso_override;
 	size_t vivso_override_len;
 
 #ifndef SMALL
+	size_t vivco_len;
+	struct vivco *vivco;
 	size_t vsio_len;
 	struct vsio *vsio;
 	size_t vsio6_len;
diff --git a/src/ipv6.c b/src/ipv6.c
index 156b24c6..a0be7c04 100644
--- a/src/ipv6.c
+++ b/src/ipv6.c
@@ -674,7 +674,7 @@ ipv6_getstate(struct interface *ifp)
 }
 
 static int
-ipv6_addaddr1(struct ipv6_addr *ia, const struct timespec *now)
+ipv6_addaddr1(struct ipv6_addr *ia, struct timespec *now)
 {
 	struct interface *ifp;
 	uint32_t pltime, vltime;
@@ -711,31 +711,11 @@ ipv6_addaddr1(struct ipv6_addr *ia, const struct timespec *now)
 		ia->prefix_vltime = ia->prefix_pltime = ND6_INFINITE_LIFETIME;
 	}
 
-	if (timespecisset(&ia->acquired) &&
-	    (ia->prefix_pltime != ND6_INFINITE_LIFETIME ||
-	    ia->prefix_vltime != ND6_INFINITE_LIFETIME))
-	{
-		uint32_t elapsed;
-		struct timespec n;
-
-		if (now == NULL) {
-			clock_gettime(CLOCK_MONOTONIC, &n);
-			now = &n;
-		}
-		elapsed = (uint32_t)eloop_timespec_diff(now, &ia->acquired,
-		    NULL);
-		if (ia->prefix_pltime != ND6_INFINITE_LIFETIME) {
-			if (elapsed > ia->prefix_pltime)
-				ia->prefix_pltime = 0;
-			else
-				ia->prefix_pltime -= elapsed;
-		}
-		if (ia->prefix_vltime != ND6_INFINITE_LIFETIME) {
-			if (elapsed > ia->prefix_vltime)
-				ia->prefix_vltime = 0;
-			else
-				ia->prefix_vltime -= elapsed;
-		}
+	if (timespecisset(&ia->acquired)) {
+		ia->prefix_pltime = lifetime_left(ia->prefix_pltime,
+		    &ia->acquired, now);
+		ia->prefix_vltime = lifetime_left(ia->prefix_vltime,
+		    &ia->acquired, now);
 	}
 
 	loglevel = ia->flags & IPV6_AF_NEW ? LOG_INFO : LOG_DEBUG;
@@ -880,7 +860,7 @@ ipv6_aliasaddr(struct ipv6_addr *ia, struct ipv6_addr **repl)
 #endif
 
 int
-ipv6_addaddr(struct ipv6_addr *ia, const struct timespec *now)
+ipv6_addaddr(struct ipv6_addr *ia, struct timespec *now)
 {
 	int r;
 #ifdef ALIAS_ADDR
@@ -975,8 +955,6 @@ ipv6_doaddr(struct ipv6_addr *ia, struct timespec *now)
 	    IN6_IS_ADDR_UNSPECIFIED(&ia->addr))
 		return 0;
 
-	if (!timespecisset(now))
-		clock_gettime(CLOCK_MONOTONIC, now);
 	ipv6_addaddr(ia, now);
 	return ia->flags & IPV6_AF_NEW ? 1 : 0;
 }
@@ -1070,12 +1048,7 @@ ipv6_freedrop_addrs(struct ipv6_addrhead *addrs, int drop,
 					ipv6_deleteaddr(ap);
 				if (!(ap->iface->options->options &
 				    DHCPCD_EXITING) && apf)
-				{
-					if (!timespecisset(&now))
-						clock_gettime(CLOCK_MONOTONIC,
-						    &now);
 					ipv6_addaddr(apf, &now);
-				}
 				if (drop == 2)
 					ipv6_freeaddr(ap);
 			}
@@ -2073,7 +2046,7 @@ ipv6_settemptime(struct ipv6_addr *ia, int flags)
 }
 
 void
-ipv6_addtempaddrs(struct interface *ifp, const struct timespec *now)
+ipv6_addtempaddrs(struct interface *ifp, struct timespec *now)
 {
 	struct ipv6_state *state;
 	struct ipv6_addr *ia;
@@ -2306,7 +2279,7 @@ inet6_raroutes(rb_tree_t *routes, struct dhcpcd_ctx *ctx)
 	if (ctx->ra_routers == NULL)
 		return 0;
 
-	clock_gettime(CLOCK_MONOTONIC, &now);
+	timespecclear(&now);
 
 	TAILQ_FOREACH(rap, ctx->ra_routers, next) {
 		if (rap->expired)
@@ -2328,7 +2301,8 @@ inet6_raroutes(rb_tree_t *routes, struct dhcpcd_ctx *ctx)
 #ifdef HAVE_ROUTE_PREF
 			rt->rt_pref = ipv6nd_rtpref(rinfo->flags);
 #endif
-			rt->rt_expires = lifetime_left(rinfo->lifetime, &rinfo->acquired, &now);
+			rt->rt_expires = lifetime_left(rinfo->lifetime,
+			    &rinfo->acquired, &now);
 			rt->rt_updated = rinfo->acquired;
 
 			rt_proto_add(routes, rt);
@@ -2344,7 +2318,9 @@ inet6_raroutes(rb_tree_t *routes, struct dhcpcd_ctx *ctx)
 #ifdef HAVE_ROUTE_PREF
 				rt->rt_pref = ipv6nd_rtpref(rap->flags);
 #endif
-				rt->rt_expires = lifetime_left(addr->prefix_vltime, &addr->acquired, &now);
+				rt->rt_expires =
+				    lifetime_left(addr->prefix_vltime,
+				    &addr->acquired, &now);
 				rt->rt_updated = addr->acquired;
 
 				rt_proto_add(routes, rt);
@@ -2378,7 +2354,8 @@ inet6_raroutes(rb_tree_t *routes, struct dhcpcd_ctx *ctx)
 #ifdef HAVE_ROUTE_PREF
 		rt->rt_pref = ipv6nd_rtpref(rap->flags);
 #endif
-		rt->rt_expires = lifetime_left(rap->lifetime, &rap->acquired, &now);
+		rt->rt_expires = lifetime_left(rap->lifetime,
+		    &rap->acquired, &now);
 		rt->rt_updated = rap->acquired;
 
 		rt_proto_add(routes, rt);
diff --git a/src/ipv6.h b/src/ipv6.h
index 6351cd4c..2304d95c 100644
--- a/src/ipv6.h
+++ b/src/ipv6.h
@@ -254,7 +254,7 @@ int ipv6_userprefix( const struct in6_addr *, short prefix_len,
 void ipv6_checkaddrflags(void *);
 void ipv6_markaddrsstale(struct interface *, unsigned int);
 void ipv6_deletestaleaddrs(struct interface *);
-int ipv6_addaddr(struct ipv6_addr *, const struct timespec *);
+int ipv6_addaddr(struct ipv6_addr *, struct timespec *);
 int ipv6_doaddr(struct ipv6_addr *, struct timespec *);
 ssize_t ipv6_addaddrs(struct ipv6_addrhead *addrs);
 void ipv6_deleteaddr(struct ipv6_addr *);
@@ -289,7 +289,7 @@ void ipv6_freedrop(struct interface *, int);
 struct ipv6_addr *ipv6_createtempaddr(struct ipv6_addr *,
     const struct timespec *);
 struct ipv6_addr *ipv6_settemptime(struct ipv6_addr *, int);
-void ipv6_addtempaddrs(struct interface *, const struct timespec *);
+void ipv6_addtempaddrs(struct interface *, struct timespec *);
 void ipv6_regentempaddrs(void *);
 #endif
 
diff --git a/src/ipv6nd.c b/src/ipv6nd.c
index bfaf9274..b1bdfecb 100644
--- a/src/ipv6nd.c
+++ b/src/ipv6nd.c
@@ -1702,7 +1702,6 @@ ipv6nd_expirera(void *arg)
 	struct interface *ifp;
 	struct ra *rap, *ran;
 	struct timespec now;
-	uint32_t elapsed;
 	bool expired, valid;
 	struct ipv6_addr *ia;
 	struct routeinfo *rinfo, *rinfob;
@@ -1714,11 +1713,11 @@ ipv6nd_expirera(void *arg)
 #endif
 	struct nd_opt_dnssl dnssl;
 	struct nd_opt_rdnss rdnss;
-	unsigned int next = 0, ltime;
+	uint32_t next = 0, ltime, elapsed;
 	size_t nexpired = 0;
 
 	ifp = arg;
-	clock_gettime(CLOCK_MONOTONIC, &now);
+	timespecclear(&now);
 	expired = false;
 
 	TAILQ_FOREACH_SAFE(rap, ifp->ctx->ra_routers, next, ran) {
@@ -1726,10 +1725,10 @@ ipv6nd_expirera(void *arg)
 			continue;
 		valid = false;
 		/* lifetime may be set to infinite by rfc4191 route information */
-		if (rap->lifetime && rap->lifetime != ND6_INFINITE_LIFETIME) {
-			elapsed = (uint32_t)eloop_timespec_diff(&now,
-			    &rap->acquired, NULL);
-			if (elapsed >= rap->lifetime || rap->doexpire) {
+		if (rap->lifetime) {
+			ltime = lifetime_left(rap->lifetime,
+			    &rap->acquired, &now);
+			if (ltime == 0 || rap->doexpire) {
 				if (!rap->expired) {
 					logwarnx("%s: %s: router expired",
 					    ifp->name, rap->sfrom);
@@ -1738,7 +1737,6 @@ ipv6nd_expirera(void *arg)
 				}
 			} else {
 				valid = true;
-				ltime = rap->lifetime - elapsed;
 				if (next == 0 || ltime < next)
 					next = ltime;
 			}
@@ -1750,15 +1748,9 @@ ipv6nd_expirera(void *arg)
 		TAILQ_FOREACH(ia, &rap->addrs, next) {
 			if (ia->prefix_vltime == 0)
 				continue;
-			if (ia->prefix_vltime == ND6_INFINITE_LIFETIME &&
-			    !rap->doexpire)
-			{
-				valid = true;
-				continue;
-			}
-			elapsed = (uint32_t)eloop_timespec_diff(&now,
-			    &ia->acquired, NULL);
-			if (elapsed >= ia->prefix_vltime || rap->doexpire) {
+			ltime = lifetime_left(ia->prefix_vltime,
+			    &ia->acquired, &now);
+			if (ltime == 0 || rap->doexpire) {
 				if (ia->flags & IPV6_AF_ADDED) {
 					logwarnx("%s: expired %s %s",
 					    ia->iface->name,
@@ -1776,7 +1768,6 @@ ipv6nd_expirera(void *arg)
 				expired = true;
 			} else {
 				valid = true;
-				ltime = ia->prefix_vltime - elapsed;
 				if (next == 0 || ltime < next)
 					next = ltime;
 			}
@@ -1784,12 +1775,9 @@ ipv6nd_expirera(void *arg)
 
 		/* Expire route information */
 		TAILQ_FOREACH_SAFE(rinfo, &rap->rinfos, next, rinfob) {
-			if (rinfo->lifetime == ND6_INFINITE_LIFETIME &&
-			    !rap->doexpire)
-				continue;
-			elapsed = (uint32_t)eloop_timespec_diff(&now,
-			    &rinfo->acquired, NULL);
-			if (elapsed >= rinfo->lifetime || rap->doexpire) {
+			ltime = lifetime_left(rinfo->lifetime,
+			    &rinfo->acquired, &now);
+			if (ltime == 0 || rap->doexpire) {
 				logwarnx("%s: expired route %s",
 				    rap->iface->name, rinfo->sprefix);
 				TAILQ_REMOVE(&rap->rinfos, rinfo, next);