diff --git a/libknet/tests/api_knet_handle_pmtud_set.c b/libknet/tests/api_knet_handle_pmtud_set.c
index 7a7ffb34..44043688 100644
--- a/libknet/tests/api_knet_handle_pmtud_set.c
+++ b/libknet/tests/api_knet_handle_pmtud_set.c
@@ -1,226 +1,226 @@
 /*
  * Copyright (C) 2016-2019 Red Hat, Inc.  All rights reserved.
  *
  * Authors: Fabio M. Di Nitto <fabbione@kronosnet.org>
  *
  * This software licensed under GPL-2.0+
  */
 
 #include "config.h"
 
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #include "libknet.h"
 
 #include "internals.h"
 #include "test-common.h"
 
 static int private_data;
 
 static void sock_notify(void *pvt_data,
 			int datafd,
 			int8_t channel,
 			uint8_t tx_rx,
 			int error,
 			int errorno)
 {
 	return;
 }
 
 static void test(void)
 {
 	knet_handle_t knet_h;
 	int logfds[2];
 	unsigned int iface_mtu = 0, data_mtu;
 	int datafd = 0;
 	int8_t channel = 0;
 	struct sockaddr_storage lo;
 
 	if (make_local_sockaddr(&lo, 0) < 0) {
 		printf("Unable to convert loopback to sockaddr: %s\n", strerror(errno));
 		exit(FAIL);
 	}
 
 	printf("Test knet_handle_pmtud_set incorrect knet_h\n");
 
 	if ((!knet_handle_pmtud_set(NULL, iface_mtu)) || (errno != EINVAL)) {
 		printf("knet_handle_pmtud_set accepted invalid knet_h or returned incorrect error: %s\n", strerror(errno));
 		exit(FAIL);
 	}
 
 	setup_logpipes(logfds);
 
 	knet_h = knet_handle_start(logfds, KNET_LOG_DEBUG);
 
 	flush_logs(logfds[0], stdout);
 
 	iface_mtu = KNET_PMTUD_SIZE_V4 + 1;
 	printf("Test knet_handle_pmtud_set with wrong iface_mtu\n");
 	if ((!knet_handle_pmtud_set(knet_h, iface_mtu)) || (errno != EINVAL)) {
 		printf("knet_handle_pmtud_set accepted invalid data_mtu or returned incorrect error: %s\n", strerror(errno));
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
 	}
 
 	if (knet_handle_enable_sock_notify(knet_h, &private_data, sock_notify) < 0) {
 		printf("knet_handle_enable_sock_notify failed: %s\n", strerror(errno));
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
         }
 
 	datafd = 0;
 	channel = -1;
 
 	if (knet_handle_add_datafd(knet_h, &datafd, &channel) < 0) {
 		printf("knet_handle_add_datafd failed: %s\n", strerror(errno));
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
 	}
 
 	if (knet_host_add(knet_h, 1) < 0) {
 		printf("knet_host_add failed: %s\n", strerror(errno));
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
 	}
 
 	if (knet_link_set_config(knet_h, 1, 0, KNET_TRANSPORT_UDP, &lo, &lo, 0) < 0) {
 		printf("Unable to configure link: %s\n", strerror(errno));
 		knet_host_remove(knet_h, 1);
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
 	}
 
 	if (knet_link_set_pong_count(knet_h, 1, 0, 1) < 0) {
 		printf("knet_link_set_pong_count failed: %s\n", strerror(errno));
 		knet_host_remove(knet_h, 1);
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
 	}
 
 	if (knet_link_set_enable(knet_h, 1, 0, 1) < 0) {
 		printf("knet_link_set_enable failed: %s\n", strerror(errno));
 		knet_link_clear_config(knet_h, 1, 0);
 		knet_host_remove(knet_h, 1);
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
 	}
 
 	if (wait_for_host(knet_h, 1, 4, logfds[0], stdout) < 0) {
 		printf("timeout waiting for host to be reachable");
 		knet_link_set_enable(knet_h, 1, 0, 0);
 		knet_link_clear_config(knet_h, 1, 0);
 		knet_host_remove(knet_h, 1);
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
 	}
 
 	flush_logs(logfds[0], stdout);
 
 	if (knet_handle_pmtud_get(knet_h, &data_mtu) < 0) {
 		printf("knet_handle_pmtud_get failed error: %s\n", strerror(errno));
 		knet_link_set_enable(knet_h, 1, 0, 0);
 		knet_link_clear_config(knet_h, 1, 0);
 		knet_host_remove(knet_h, 1);
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
 	}
 
 	/*
 	 * 28 = IP (20) + UDP (8)
 	 */
 	iface_mtu = data_mtu + 28 + KNET_HEADER_ALL_SIZE - 64;
 	printf("Test knet_handle_pmtud_set with iface_mtu %u\n", iface_mtu);
 
 	if (knet_handle_pmtud_set(knet_h, iface_mtu) < 0) {
 		printf("knet_handle_pmtud_set failed error: %s\n", strerror(errno));
 		knet_link_set_enable(knet_h, 1, 0, 0);
 		knet_link_clear_config(knet_h, 1, 0);
 		knet_host_remove(knet_h, 1);
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
 	}
 
 	/*
 	 * wait for PMTUd to pick up the change
 	 */
 	sleep(1);
 	flush_logs(logfds[0], stdout);
 
 	if (knet_h->data_mtu != data_mtu - 64) {
 		printf("knet_handle_pmtud_set failed to set the value\n");
 		knet_link_set_enable(knet_h, 1, 0, 0);
 		knet_link_clear_config(knet_h, 1, 0);
 		knet_host_remove(knet_h, 1);
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
 	}
 
 	printf("Test knet_handle_pmtud_set with iface_mtu 0\n");
 	if (knet_handle_pmtud_set(knet_h, 0) < 0) {
 		printf("knet_handle_pmtud_set failed error: %s\n", strerror(errno));
 		knet_link_set_enable(knet_h, 1, 0, 0);
 		knet_link_clear_config(knet_h, 1, 0);
 		knet_host_remove(knet_h, 1);
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
 	}
 
 	/*
 	 * wait for PMTUd to pick up the change
 	 */
-	sleep(1);
+	sleep(2);
 	flush_logs(logfds[0], stdout);
 
 	if (knet_h->data_mtu != data_mtu) {
 		printf("knet_handle_pmtud_set failed to redetect MTU\n");
 		knet_link_set_enable(knet_h, 1, 0, 0);
 		knet_link_clear_config(knet_h, 1, 0);
 		knet_host_remove(knet_h, 1);
 		knet_handle_free(knet_h);
 		flush_logs(logfds[0], stdout);
 		close_logpipes(logfds);
 		exit(FAIL);
 	}
 
 	knet_link_set_enable(knet_h, 1, 0, 0);
 	knet_link_clear_config(knet_h, 1, 0);
 	knet_host_remove(knet_h, 1);
 	knet_handle_free(knet_h);
 	flush_logs(logfds[0], stdout);
 	close_logpipes(logfds);
 }
 
 int main(int argc, char *argv[])
 {
 	test();
 
 	return PASS;
 }
diff --git a/libnozzle/tests/test-common.c b/libnozzle/tests/test-common.c
index b36be79c..3afd2ec8 100644
--- a/libnozzle/tests/test-common.c
+++ b/libnozzle/tests/test-common.c
@@ -1,159 +1,159 @@
 /*
  * Copyright (C) 2018-2019 Red Hat, Inc.  All rights reserved.
  *
  * Author: Fabio M. Di Nitto <fabbione@kronosnet.org>
  *
  * This software licensed under GPL-2.0+
  */
 
 #include "config.h"
 
 #include <string.h>
 #include <sys/types.h>
 #include <ifaddrs.h>
 #include <limits.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <stdio.h>
 #include <stdlib.h>
 
 #include "test-common.h"
 
 void need_root(void)
 {
 	if (geteuid() != 0) {
 		printf("This test requires root privileges\n");
 		exit(SKIP);
 	}
 }
 
 int test_iface(char *name, size_t size, const char *updownpath)
 {
 	nozzle_t nozzle;
 
 	nozzle=nozzle_open(name, size, updownpath);
 	if (!nozzle) {
 		printf("Unable to open nozzle.\n");
 		return -1;
 	}
 	printf("Created interface: %s\n", name);
 
 	if (is_if_in_system(name) > 0) {
 		printf("Found interface %s on the system\n", name);
 	} else {
 		printf("Unable to find interface %s on the system\n", name);
 	}
 
 	if (!nozzle_get_handle_by_name(name)) {
 		printf("Unable to find interface %s in nozzle db\n", name);
 	} else {
 		printf("Found interface %s in nozzle db\n", name);
 	}
 
 	nozzle_close(nozzle);
 
 	if (is_if_in_system(name) == 0)
 		printf("Successfully removed interface %s from the system\n", name);
 
 	return 0;
 }
 
 int is_if_in_system(char *name)
 {
 	struct ifaddrs *ifap = NULL;
 	struct ifaddrs *ifa;
 	int found = 0;
 
 	if (getifaddrs(&ifap) < 0) {
 		printf("Unable to get interface list.\n");
 		return -1;
 	}
 
 	ifa = ifap;
 
 	while (ifa) {
 		if (!strncmp(name, ifa->ifa_name, IFNAMSIZ)) {
 			found = 1;
 			break;
 		}
 		ifa=ifa->ifa_next;
 	}
 
 	freeifaddrs(ifap);
 	return found;
 }
 
 int get_random_byte(void)
 {
 	pid_t mypid;
 	uint8_t *pid;
 	uint8_t randombyte = 0;
 	uint8_t i;
 
 	if (sizeof(pid_t) < 4) {
 		printf("pid_t is smaller than 4 bytes?\n");
 		exit(77);
 	}
 
 	mypid = getpid();
 	pid = (uint8_t *)&mypid;
 
 	for (i = 0; i < sizeof(pid_t); i++) {
 		if (pid[i] == 0) {
 			pid[i] = 128;
 		}
 	}
 
 	randombyte = pid[1];
 
 	return randombyte;
 }
 
 void make_local_ips(char *testipv4_1, char *testipv4_2, char *testipv6_1, char *testipv6_2)
 {
 	pid_t mypid;
 	uint8_t *pid;
 	uint8_t i;
 
 	memset(testipv4_1, 0, IPBUFSIZE);
 	memset(testipv4_2, 0, IPBUFSIZE);
 	memset(testipv6_1, 0, IPBUFSIZE);
 	memset(testipv6_2, 0, IPBUFSIZE);
 
 	mypid = getpid();
 	pid = (uint8_t *)&mypid;
 
 	for (i = 0; i < sizeof(pid_t); i++) {
-		if (pid[i] == 0) {
+		if ((pid[i] == 0) || (pid[i] == 255)) {
 			pid[i] = 128;
 		}
 	}
 
 	snprintf(testipv4_1,
 		 IPBUFSIZE - 1,
 		 "127.%u.%u.%u",
 		 pid[1],
 		 pid[2],
 		 pid[0]);
 
 	snprintf(testipv4_2,
 		 IPBUFSIZE - 1,
 		 "127.%u.%d.%u",
 		 pid[1],
 		 pid[2]+1,
 		 pid[0]);
 
 	snprintf(testipv6_1,
 		 IPBUFSIZE - 1,
 		 "fd%x:%x%x::1",
 		 pid[1],
 		 pid[2],
 		 pid[0]);
 
 	snprintf(testipv6_2,
 		 IPBUFSIZE - 1,
 		 "fd%x:%x%x:1::1",
 		 pid[1],
 		 pid[2],
 		 pid[0]);
 }