diff --git a/tests/lib/Makefile.am b/tests/lib/Makefile.am
index ae54127..95d6901 100644
--- a/tests/lib/Makefile.am
+++ b/tests/lib/Makefile.am
@@ -1,8 +1,9 @@
 AM_CFLAGS = -Wall -I$(top_srcdir)/include $(LIBOSMOCORE_CFLAGS) -g
 
-EXTRA_DIST = ippool_test.ok ippool_test.err
+EXTRA_DIST = ippool_test.ok ippool_test.err \
+	     in46a_test.ok
 
-noinst_PROGRAMS = ippool_test
+noinst_PROGRAMS = ippool_test in46a_test
 
 ippool_test_SOURCES = \
 	ippool_test.c \
@@ -12,3 +13,12 @@
 	$(top_builddir)/lib/libmisc.a \
 	$(LIBOSMOCORE_LIBS) \
 	$(NULL)
+
+in46a_test_SOURCES = \
+	in46a_test.c \
+	$(NULL)
+
+in46a_test_LDADD = \
+	$(top_builddir)/lib/libmisc.a \
+	$(LIBOSMOCORE_LIBS) \
+	$(NULL)
diff --git a/tests/lib/in46a_test.c b/tests/lib/in46a_test.c
new file mode 100644
index 0000000..d6215e7
--- /dev/null
+++ b/tests/lib/in46a_test.c
@@ -0,0 +1,265 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+#include <osmocom/core/utils.h>
+#include <osmocom/core/application.h>
+#include <osmocom/core/logging.h>
+
+#include "../../lib/in46_addr.h"
+#include "../../lib/syserr.h"
+
+static const struct in46_addr g_ia4 = {
+	.len = 4,
+	.v4.s_addr = 0x0d0c0b0a,
+};
+
+static const struct in46_addr g_ia6 = {
+	.len = 16,
+	.v6.s6_addr = { 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 },
+};
+
+static void test_in46a_to_af(void)
+{
+	struct in46_addr ia;
+
+	printf("Testing in46a_to_af()\n");
+
+	OSMO_ASSERT(in46a_to_af(&g_ia4) == AF_INET);
+	OSMO_ASSERT(in46a_to_af(&g_ia6) == AF_INET6);
+
+	ia.len = 8;
+	OSMO_ASSERT(in46a_to_af(&ia) == AF_INET6);
+}
+
+static void test_in46a_to_sas(void)
+{
+	struct sockaddr_storage ss;
+	struct sockaddr_in *sin = (struct sockaddr_in *) &ss;
+	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &ss;
+
+	printf("Testing in46a_to_sas()\n");
+
+	memset(&ss, 0, sizeof(ss));
+	OSMO_ASSERT(in46a_to_sas(&ss, &g_ia4) == 0);
+	OSMO_ASSERT(sin->sin_family == AF_INET);
+	OSMO_ASSERT(sin->sin_addr.s_addr == g_ia4.v4.s_addr);
+
+	memset(&ss, 0, sizeof(ss));
+	OSMO_ASSERT(in46a_to_sas(&ss, &g_ia6) == 0);
+	OSMO_ASSERT(sin6->sin6_family == AF_INET6);
+	OSMO_ASSERT(!memcmp(&sin6->sin6_addr, &g_ia6.v6, sizeof(sin6->sin6_addr)));
+}
+
+static void test_in46a_ntop(void)
+{
+	struct in46_addr ia;
+	char buf[256];
+	const char *res;
+
+	printf("Testing in46a_ntop()\n");
+
+	res = in46a_ntop(NULL, buf, sizeof(buf));
+	OSMO_ASSERT(res && !strcmp(res, "UNDEFINED"));
+	printf("res = %s\n", res);
+
+	ia.len = 0;
+	res = in46a_ntop(&ia, buf, sizeof(buf));
+	printf("res = %s\n", res);
+	OSMO_ASSERT(res && !strcmp(res, "UNDEFINED"));
+
+	ia.len = 4;
+	ia.v4.s_addr = htonl(0x01020304);
+	res = in46a_ntop(&ia, buf, sizeof(buf));
+	OSMO_ASSERT(res && !strcmp(res, "1.2.3.4"));
+	printf("res = %s\n", res);
+
+	res = in46a_ntop(&g_ia6, buf, sizeof(buf));
+	OSMO_ASSERT(res && !strcmp(res, "102:304:506:708:90a:b0c:d0e:f10"));
+	printf("res = %s\n", res);
+}
+
+static void test_in46p_ntoa(void)
+{
+	const struct in46_prefix ip46 = {
+		.prefixlen = 24,
+		.addr = {
+			.len = 4,
+			.v4.s_addr = htonl(0x10203000),
+		},
+	};
+	printf("in46p_ntoa() returns %s\n", in46p_ntoa(&ip46));
+}
+
+static void test_in46a_equal(void)
+{
+	struct in46_addr b;
+
+	printf("Testing in46a_equal()\n");
+
+	memset(&b, 0xff, sizeof(b));
+	b.len = g_ia4.len;
+	b.v4.s_addr = g_ia4.v4.s_addr;
+	OSMO_ASSERT(in46a_equal(&g_ia4, &b));
+
+	memset(&b, 0xff, sizeof(b));
+	b.len = g_ia6.len;
+	b.v6 = g_ia6.v6;
+	OSMO_ASSERT(in46a_equal(&g_ia6, &b));
+
+}
+
+
+static int log_in46a_within_mask(const struct in46_addr *addr, const struct in46_addr *net,
+				 size_t prefixlen)
+{
+	int rc;
+
+	printf("in46a_within_mask(%s, ", in46a_ntoa(addr));
+	printf("%s, %lu) = ", in46a_ntoa(net), prefixlen);
+
+	rc = in46a_within_mask(addr, net, prefixlen);
+	printf("%d\n", rc);
+
+	return rc;
+}
+
+static void test_in46a_within_mask(void)
+{
+	struct in46_addr addr, mask;
+
+	printf("Testing in46a_within_mask()\n");
+
+	addr = g_ia4;
+	mask = g_ia4;
+	OSMO_ASSERT(log_in46a_within_mask(&addr, &mask, 32));
+
+	mask.v4.s_addr = htonl( ntohl(mask.v4.s_addr) & 0xfffffffC );
+	OSMO_ASSERT(log_in46a_within_mask(&addr, &mask, 30));
+
+	mask.v4.s_addr = htonl( ntohl(mask.v4.s_addr) & 0xfff80000 );
+	OSMO_ASSERT(log_in46a_within_mask(&addr, &mask, 13));
+
+	addr.v4.s_addr = htonl(ntohl(addr.v4.s_addr) + 1);
+	mask = g_ia4;
+	OSMO_ASSERT(!log_in46a_within_mask(&addr, &mask, 32));
+	mask.v4.s_addr = htonl( ntohl(mask.v4.s_addr) & 0xfffffffC );
+	OSMO_ASSERT(log_in46a_within_mask(&addr, &mask, 30));
+}
+
+static void test_in46a_to_eua(void)
+{
+	const struct in46_addr ia_v6_8 = {
+		.len = 8,
+		.v6.s6_addr = { 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 },
+	};
+	struct ul66_t eua;
+
+	printf("testing in46a_to_eua()\n");
+
+#if 0	/* triggers assert in current implementation */
+	const struct in46_addr ia_invalid = { .len = 3, };
+	OSMO_ASSERT(in46a_to_eua(&ia_invalid, &eua) < 0);
+#endif
+
+	/* IPv4 address */
+	OSMO_ASSERT(in46a_to_eua(&g_ia4, &eua) == 0);
+	OSMO_ASSERT(eua.v[0] == PDP_EUA_ORG_IETF);
+	OSMO_ASSERT(eua.v[1] == PDP_EUA_TYPE_v4);
+	OSMO_ASSERT(*(uint32_t *) &eua.v[2] == g_ia4.v4.s_addr);
+
+	/* IPv6 address */
+	OSMO_ASSERT(in46a_to_eua(&g_ia6, &eua) == 0);
+	OSMO_ASSERT(eua.v[0] == PDP_EUA_ORG_IETF);
+	OSMO_ASSERT(eua.v[1] == PDP_EUA_TYPE_v6);
+	OSMO_ASSERT(!memcmp(&eua.v[2], &g_ia6.v6, 16));
+
+	/* IPv6 address with prefix / length 8 */
+	OSMO_ASSERT(in46a_to_eua(&ia_v6_8, &eua) == 0);
+	OSMO_ASSERT(eua.v[0] == PDP_EUA_ORG_IETF);
+	OSMO_ASSERT(eua.v[1] == PDP_EUA_TYPE_v6);
+	OSMO_ASSERT(!memcmp(&eua.v[2], &ia_v6_8.v6, 16));
+}
+
+static void test_in46a_from_eua(void)
+{
+	struct in46_addr ia;
+	struct ul66_t eua;
+	const uint8_t v4_unspec[] = { PDP_EUA_ORG_IETF, PDP_EUA_TYPE_v4 };
+	const uint8_t v4_spec[] = { PDP_EUA_ORG_IETF, PDP_EUA_TYPE_v4, 1,2,3,4 };
+	const uint8_t v6_unspec[] = { PDP_EUA_ORG_IETF, PDP_EUA_TYPE_v6 };
+	const uint8_t v6_spec[] = { PDP_EUA_ORG_IETF, PDP_EUA_TYPE_v6,
+				    1,2,3,4,5,6,7,8,9,0xa,0xb,0xc,0xd,0xe,0xf,0x10 };
+
+	memset(&eua, 0, sizeof(eua));
+
+	printf("Testing in46a_from_eua()\n");
+
+	/* default: v4 unspec */
+	OSMO_ASSERT(in46a_from_eua(&eua, &ia) == 0);
+	OSMO_ASSERT(ia.len == 4);
+	OSMO_ASSERT(ia.v4.s_addr == 0);
+
+	/* invalid */
+	eua.v[0] = 0x23;
+	eua.v[1] = PDP_EUA_TYPE_v4;
+	eua.l = 6;
+	OSMO_ASSERT(in46a_from_eua(&eua, &ia) < 0);
+
+	/* invalid */
+	eua.v[0] = PDP_EUA_ORG_IETF;
+	eua.v[1] = 0x23;
+	eua.l = 6;
+	OSMO_ASSERT(in46a_from_eua(&eua, &ia) < 0);
+
+	/* unspecified V4 */
+	memcpy(eua.v, v4_unspec, sizeof(v4_unspec));
+	eua.l = sizeof(v4_unspec);
+	OSMO_ASSERT(in46a_from_eua(&eua, &ia) == 0);
+	OSMO_ASSERT(ia.len == 4);
+	OSMO_ASSERT(ia.v4.s_addr == 0);
+
+	/* specified V4 */
+	memcpy(eua.v, v4_spec, sizeof(v4_spec));
+	eua.l = sizeof(v4_spec);
+	OSMO_ASSERT(in46a_from_eua(&eua, &ia) == 0);
+	OSMO_ASSERT(ia.len == 4);
+	OSMO_ASSERT(ia.v4.s_addr == htonl(0x01020304));
+
+	/* unspecified V6 */
+	memcpy(eua.v, v6_unspec, sizeof(v6_unspec));
+	eua.l = sizeof(v6_unspec);
+	OSMO_ASSERT(in46a_from_eua(&eua, &ia) == 0);
+	OSMO_ASSERT(ia.len == 16);
+	OSMO_ASSERT(IN6_IS_ADDR_UNSPECIFIED(&ia.v6));
+
+	/* specified V6 */
+	memcpy(eua.v, v6_spec, sizeof(v6_spec));
+	eua.l = sizeof(v6_spec);
+	OSMO_ASSERT(in46a_from_eua(&eua, &ia) == 0);
+	OSMO_ASSERT(ia.len == 16);
+	OSMO_ASSERT(!memcmp(&ia.v6, v6_spec+2, ia.len));
+}
+
+int main(int argc, char **argv)
+{
+	osmo_init_logging(&log_info);
+	log_set_use_color(osmo_stderr_target, 0);
+	log_set_print_filename(osmo_stderr_target, 0);
+
+	srand(time(NULL));
+
+	test_in46a_to_af();
+	test_in46a_to_sas();
+	test_in46a_ntop();
+	test_in46p_ntoa();
+	test_in46a_equal();
+	test_in46a_within_mask();
+	test_in46a_to_eua();
+	test_in46a_from_eua();
+}
diff --git a/tests/lib/in46a_test.ok b/tests/lib/in46a_test.ok
new file mode 100644
index 0000000..b115444
--- /dev/null
+++ b/tests/lib/in46a_test.ok
@@ -0,0 +1,17 @@
+Testing in46a_to_af()
+Testing in46a_to_sas()
+Testing in46a_ntop()
+res = UNDEFINED
+res = UNDEFINED
+res = 1.2.3.4
+res = 102:304:506:708:90a:b0c:d0e:f10
+in46p_ntoa() returns 16.32.48.0/24
+Testing in46a_equal()
+Testing in46a_within_mask()
+in46a_within_mask(10.11.12.13, 10.11.12.13, 32) = 1
+in46a_within_mask(10.11.12.13, 10.11.12.12, 30) = 1
+in46a_within_mask(10.11.12.13, 10.8.0.0, 13) = 1
+in46a_within_mask(10.11.12.14, 10.11.12.13, 32) = 0
+in46a_within_mask(10.11.12.14, 10.11.12.12, 30) = 1
+testing in46a_to_eua()
+Testing in46a_from_eua()