diff --git a/lib/isc/include/isc/net.h b/lib/isc/include/isc/net.h
index e7d0d565bf..827efe8f01 100644
--- a/lib/isc/include/isc/net.h
+++ b/lib/isc/include/isc/net.h
@@ -244,21 +244,4 @@ isc_net_enableipv4(void);
 void
 isc_net_enableipv6(void);
 
-isc_result_t
-isc_net_getudpportrange(int af, in_port_t *low, in_port_t *high);
-/*%<
- * Returns system's default range of ephemeral UDP ports, if defined.
- * If the range is not available or unknown, ISC_NET_PORTRANGELOW and
- * ISC_NET_PORTRANGEHIGH will be returned.
- *
- * Requires:
- *
- *\li	'low' and 'high' must be non NULL.
- *
- * Returns:
- *
- *\li	*low and *high will be the ports specifying the low and high ends of
- *	the range.
- */
-
 ISC_LANG_ENDDECLS
diff --git a/lib/isc/net.c b/lib/isc/net.c
index 549e7a94fb..5a600047f6 100644
--- a/lib/isc/net.c
+++ b/lib/isc/net.c
@@ -330,126 +330,6 @@ isc_net_probe_ipv6pktinfo(void) {
 	return (ipv6pktinfo_result);
 }
 
-#if defined(USE_SYSCTL_PORTRANGE)
-#if defined(HAVE_SYSCTLBYNAME)
-static isc_result_t
-getudpportrange_sysctl(int af, in_port_t *low, in_port_t *high) {
-	int port_low, port_high;
-	size_t portlen;
-	const char *sysctlname_lowport, *sysctlname_hiport;
-
-	if (af == AF_INET) {
-		sysctlname_lowport = SYSCTL_V4PORTRANGE_LOW;
-		sysctlname_hiport = SYSCTL_V4PORTRANGE_HIGH;
-	} else {
-		sysctlname_lowport = SYSCTL_V6PORTRANGE_LOW;
-		sysctlname_hiport = SYSCTL_V6PORTRANGE_HIGH;
-	}
-	portlen = sizeof(port_low);
-	if (sysctlbyname(sysctlname_lowport, &port_low, &portlen, NULL, 0) < 0)
-	{
-		return (ISC_R_FAILURE);
-	}
-	portlen = sizeof(port_high);
-	if (sysctlbyname(sysctlname_hiport, &port_high, &portlen, NULL, 0) < 0)
-	{
-		return (ISC_R_FAILURE);
-	}
-	if ((port_low & ~0xffff) != 0 || (port_high & ~0xffff) != 0) {
-		return (ISC_R_RANGE);
-	}
-
-	*low = (in_port_t)port_low;
-	*high = (in_port_t)port_high;
-
-	return (ISC_R_SUCCESS);
-}
-#else  /* !HAVE_SYSCTLBYNAME */
-static isc_result_t
-getudpportrange_sysctl(int af, in_port_t *low, in_port_t *high) {
-	int mib_lo4[4] = SYSCTL_V4PORTRANGE_LOW;
-	int mib_hi4[4] = SYSCTL_V4PORTRANGE_HIGH;
-	int mib_lo6[4] = SYSCTL_V6PORTRANGE_LOW;
-	int mib_hi6[4] = SYSCTL_V6PORTRANGE_HIGH;
-	int *mib_lo, *mib_hi, miblen;
-	int port_low, port_high;
-	size_t portlen;
-
-	if (af == AF_INET) {
-		mib_lo = mib_lo4;
-		mib_hi = mib_hi4;
-		miblen = sizeof(mib_lo4) / sizeof(mib_lo4[0]);
-	} else {
-		mib_lo = mib_lo6;
-		mib_hi = mib_hi6;
-		miblen = sizeof(mib_lo6) / sizeof(mib_lo6[0]);
-	}
-
-	portlen = sizeof(port_low);
-	if (sysctl(mib_lo, miblen, &port_low, &portlen, NULL, 0) < 0) {
-		return (ISC_R_FAILURE);
-	}
-
-	portlen = sizeof(port_high);
-	if (sysctl(mib_hi, miblen, &port_high, &portlen, NULL, 0) < 0) {
-		return (ISC_R_FAILURE);
-	}
-
-	if ((port_low & ~0xffff) != 0 || (port_high & ~0xffff) != 0) {
-		return (ISC_R_RANGE);
-	}
-
-	*low = (in_port_t)port_low;
-	*high = (in_port_t)port_high;
-
-	return (ISC_R_SUCCESS);
-}
-#endif /* HAVE_SYSCTLBYNAME */
-#endif /* USE_SYSCTL_PORTRANGE */
-
-isc_result_t
-isc_net_getudpportrange(int af, in_port_t *low, in_port_t *high) {
-	int result = ISC_R_FAILURE;
-#if !defined(USE_SYSCTL_PORTRANGE) && defined(__linux)
-	FILE *fp;
-#endif /* if !defined(USE_SYSCTL_PORTRANGE) && defined(__linux) */
-
-	REQUIRE(low != NULL && high != NULL);
-
-#if defined(USE_SYSCTL_PORTRANGE)
-	result = getudpportrange_sysctl(af, low, high);
-#elif defined(__linux)
-
-	UNUSED(af);
-
-	/*
-	 * Linux local ports are address family agnostic.
-	 */
-	fp = fopen("/proc/sys/net/ipv4/ip_local_port_range", "r");
-	if (fp != NULL) {
-		int n;
-		unsigned int l, h;
-
-		n = fscanf(fp, "%u %u", &l, &h);
-		if (n == 2 && (l & ~0xffff) == 0 && (h & ~0xffff) == 0) {
-			*low = l;
-			*high = h;
-			result = ISC_R_SUCCESS;
-		}
-		fclose(fp);
-	}
-#else  /* if defined(USE_SYSCTL_PORTRANGE) */
-	UNUSED(af);
-#endif /* if defined(USE_SYSCTL_PORTRANGE) */
-
-	if (result != ISC_R_SUCCESS) {
-		*low = ISC_NET_PORTRANGELOW;
-		*high = ISC_NET_PORTRANGEHIGH;
-	}
-
-	return (ISC_R_SUCCESS); /* we currently never fail in this function */
-}
-
 void
 isc_net_disableipv4(void) {
 	initialize();