diff --git a/test/src/all.py b/test/src/all.py
index 88a257b..b0c098a 100644
--- a/test/src/all.py
+++ b/test/src/all.py
@@ -30,6 +30,7 @@ from scapy.layers.inet6 import (
 )
 from scapy.layers.l2 import ARP, Ether
 from scapy.packet import Raw
+from scapy.volatile import RandInt
 
 from .conf import IPV4_ADDR, IPV6_ADDR, MAC_ADDR
 
@@ -347,13 +348,22 @@ def test_tcp_syn(iface):
         65438,
     ]
     for p in ports_to_test:
-        syn = Ether(dst=MAC_ADDR) / IP(dst=IPV4_ADDR) / TCP(flags="S", dport=p)
+        seq_init = int(RandInt())
+        syn = (
+            Ether(dst=MAC_ADDR)
+            / IP(dst=IPV4_ADDR)
+            / TCP(flags="S", dport=p, seq=seq_init)
+        )
         syn_ack = iface.sr1(syn, timeout=1)
         assert syn_ack is not None, "expecting answer, got nothing"
         check_ip_checksum(syn_ack)
-        assert TCP in syn_ack
+        assert TCP in syn_ack, "expecting TCP, got %r" % syn_ack.summary()
         syn_ack = syn_ack[TCP]
-        assert syn_ack.flags == "SA"
+        assert syn_ack.flags == "SA", "expecting TCP SA, got %r" % syn_ack.flags
+        assert syn_ack.ack == seq_init + 1, "wrong TCP ack value (%r != %r)" % (
+            syn_ack.ack,
+            seq_init + 1,
+        )
 
 
 @test
@@ -361,40 +371,56 @@ def test_ipv4_tcp_psh_ack(iface):
     ##### PSH-ACK #####
     sport = 26695
     port = 445
+    seq_init = int(RandInt())
     # send PSH-ACK first
     psh_ack = (
         Ether(dst=MAC_ADDR)
         / IP(dst=IPV4_ADDR)
-        / TCP(flags="PA", sport=sport, dport=port)
+        / TCP(flags="PA", sport=sport, dport=port, seq=seq_init)
         / Raw("payload")
     )
     syn_ack = iface.sr1(psh_ack, timeout=1)
     assert syn_ack is None, "no answer expected, got one"
     # test the anti-injection mechanism
-    syn = Ether(dst=MAC_ADDR) / IP(dst=IPV4_ADDR) / TCP(flags="S", dport=port)
+    seq_init = int(RandInt())
+    syn = (
+        Ether(dst=MAC_ADDR)
+        / IP(dst=IPV4_ADDR)
+        / TCP(flags="S", sport=sport, dport=port, seq=seq_init)
+    )
     syn_ack = iface.sr1(syn, timeout=1)
     assert syn_ack is not None, "expecting answer, got nothing"
     check_ip_checksum(syn_ack)
-    assert TCP in syn_ack
+    assert TCP in syn_ack, "expecting TCP, got %r" % syn_ack.summary()
     syn_ack = syn_ack[TCP]
-    assert syn_ack.flags == "SA"
+    assert syn_ack.flags == "SA", "expecting TCP SA, got %r" % syn_ack.flags
+    assert syn_ack.ack == seq_init + 1, "wrong TCP ack value (%r != %r)" % (
+        syn_ack.ack,
+        seq_init + 1,
+    )
     ack = Ether(dst=MAC_ADDR) / IP(dst=IPV4_ADDR) / TCP(flags="A", dport=port)
     # should fail because no ack given
-    psh_ack = Ether(dst=MAC_ADDR) / IP(dst=IPV4_ADDR) / TCP(flags="PA", dport=port)
+    psh_ack = (
+        Ether(dst=MAC_ADDR)
+        / IP(dst=IPV4_ADDR)
+        / TCP(flags="PA", sport=sport, dport=port, ack=0, seq=seq_init + 1)
+    )
     ack = iface.sr1(psh_ack, timeout=1)
     assert ack is None, "no answer expected, got one"
     # should get an answer this time
     psh_ack = (
         Ether(dst=MAC_ADDR)
         / IP(dst=IPV4_ADDR)
-        / TCP(flags="PA", dport=port, ack=syn_ack.seq + 1)
+        / TCP(
+            flags="PA", sport=sport, dport=port, ack=syn_ack.seq + 1, seq=seq_init + 1
+        )
     )
     ack = iface.sr1(psh_ack, timeout=1)
     assert ack is not None, "expecting answer, got nothing"
     check_ip_checksum(ack)
-    assert TCP in ack
+    assert TCP in ack, "expecting TCP, got %r" % ack.summary()
     ack = ack[TCP]
-    assert ack.flags == "A"
+    assert ack.flags == "A", "expecting TCP A, got %r" % syn_ack.flags
 
 
 @test
@@ -402,40 +428,55 @@ def test_ipv6_tcp_psh_ack(iface):
     ##### PSH-ACK #####
     sport = 26695
     port = 445
+    seq_init = int(RandInt())
     # send PSH-ACK first
     psh_ack = (
         Ether(dst=MAC_ADDR)
         / IPv6(dst=IPV6_ADDR)
-        / TCP(flags="PA", sport=sport, dport=port)
+        / TCP(flags="PA", sport=sport, dport=port, seq=seq_init)
         / Raw("payload")
     )
     syn_ack = iface.sr1(psh_ack, timeout=1)
     assert syn_ack is None, "no answer expected, got one"
     # test the anti-injection mechanism
-    syn = Ether(dst=MAC_ADDR) / IPv6(dst=IPV6_ADDR) / TCP(flags="S", dport=port)
+    syn = (
+        Ether(dst=MAC_ADDR)
+        / IPv6(dst=IPV6_ADDR)
+        / TCP(flags="S", sport=sport, dport=port, seq=seq_init)
+    )
     syn_ack = iface.sr1(syn, timeout=1)
     assert syn_ack is not None, "expecting answer, got nothing"
     check_ipv6_checksum(syn_ack)
-    assert TCP in syn_ack
+    assert TCP in syn_ack, "expecting TCP, got %r" % syn_ack.summary()
     syn_ack = syn_ack[TCP]
-    assert syn_ack.flags == "SA"
+    assert syn_ack.flags == "SA", "expecting TCP SA, got %r" % syn_ack.flags
+    assert syn_ack.ack == seq_init + 1, "wrong TCP ack value (%r != %r)" % (
+        syn_ack.ack,
+        seq_init + 1,
+    )
     ack = Ether(dst=MAC_ADDR) / IPv6(dst=IPV6_ADDR) / TCP(flags="A", dport=port)
     # should fail because no ack given
-    psh_ack = Ether(dst=MAC_ADDR) / IPv6(dst=IPV6_ADDR) / TCP(flags="PA", dport=port)
+    psh_ack = (
+        Ether(dst=MAC_ADDR)
+        / IPv6(dst=IPV6_ADDR)
+        / TCP(flags="PA", sport=sport, dport=port, ack=0, seq=seq_init + 1)
+    )
     ack = iface.sr1(psh_ack, timeout=1)
     assert ack is None, "no answer expected, got one"
     # should get an answer this time
     psh_ack = (
         Ether(dst=MAC_ADDR)
         / IPv6(dst=IPV6_ADDR)
-        / TCP(flags="PA", dport=port, ack=syn_ack.seq + 1)
+        / TCP(
+            flags="PA", sport=sport, dport=port, ack=syn_ack.seq + 1, seq=seq_init + 1
+        )
     )
     ack = iface.sr1(psh_ack, timeout=1)
     assert ack is not None, "expecting answer, got nothing"
     check_ipv6_checksum(ack)
-    assert TCP in ack
+    assert TCP in ack, "expecting TCP, got %r" % ack.summary()
     ack = ack[TCP]
-    assert ack.flags == "A"
+    assert ack.flags == "A", "expecting TCP A, got %r" % syn_ack.flags
 
 
 @test
@@ -443,33 +484,46 @@ def test_ipv4_tcp_http(iface):
     sport = 24592
     dports = [80, 443, 5000, 53228]
     for dport in dports:
+        seq_init = int(RandInt())
         syn = (
             Ether(dst=MAC_ADDR)
             / IP(dst=IPV4_ADDR)
-            / TCP(flags="S", sport=sport, dport=dport)
+            / TCP(flags="S", sport=sport, dport=dport, seq=seq_init)
         )
         syn_ack = iface.sr1(syn, timeout=1)
         assert syn_ack is not None, "expecting answer, got nothing"
         check_ip_checksum(syn_ack)
-        assert TCP in syn_ack
+        assert TCP in syn_ack, "expecting TCP, got %r" % syn_ack.summary()
         syn_ack = syn_ack[TCP]
-        assert syn_ack.flags == "SA"
+        assert syn_ack.flags == "SA", "expecting TCP SA, got %r" % syn_ack.flags
         ack = (
             Ether(dst=MAC_ADDR)
             / IP(dst=IPV4_ADDR)
-            / TCP(flags="A", sport=sport, dport=dport, ack=syn_ack.seq + 1)
+            / TCP(
+                flags="A",
+                sport=sport,
+                dport=dport,
+                seq=seq_init + 1,
+                ack=syn_ack.seq + 1,
+            )
         )
         _ = iface.sr1(ack, timeout=1)
         req = (
             Ether(dst=MAC_ADDR)
             / IP(dst=IPV4_ADDR)
-            / TCP(flags="PA", ack=syn_ack.seq + 1, sport=sport, dport=dport)
+            / TCP(
+                flags="PA",
+                sport=sport,
+                dport=dport,
+                seq=seq_init + 1,
+                ack=syn_ack.seq + 1,
+            )
             / Raw("GET / HTTP/1.1\r\n\r\n")
         )
         resp = iface.sr1(req, timeout=1)
         assert resp is not None, "expecting answer, got nothing"
         check_ip_checksum(resp)
-        assert TCP in resp
+        assert TCP in resp, "expecting TCP, got %r" % resp.summary()
         tcp = resp[TCP]
         assert tcp.payload.load.startswith(b"HTTP/1.1 401 Unauthorized\n")
 
@@ -479,33 +533,46 @@ def test_ipv6_tcp_http(iface):
     sport = 24592
     dports = [80, 443, 5000, 53228]
     for dport in dports:
+        seq_init = int(RandInt())
         syn = (
             Ether(dst=MAC_ADDR)
             / IPv6(dst=IPV6_ADDR)
-            / TCP(flags="S", sport=sport, dport=dport)
+            / TCP(flags="S", sport=sport, dport=dport, seq=seq_init)
         )
         syn_ack = iface.sr1(syn, timeout=1)
         assert syn_ack is not None, "expecting answer, got nothing"
         check_ipv6_checksum(syn_ack)
-        assert TCP in syn_ack
+        assert TCP in syn_ack, "expecting TCP, got %r" % syn_ack.summary()
         syn_ack = syn_ack[TCP]
         assert syn_ack.flags == "SA"
         ack = (
             Ether(dst=MAC_ADDR)
             / IPv6(dst=IPV6_ADDR)
-            / TCP(flags="A", sport=sport, dport=dport, ack=syn_ack.seq + 1)
+            / TCP(
+                flags="A",
+                sport=sport,
+                dport=dport,
+                seq=seq_init + 1,
+                ack=syn_ack.seq + 1,
+            )
         )
         _ = iface.sr1(ack, timeout=1)
         req = (
             Ether(dst=MAC_ADDR)
             / IPv6(dst=IPV6_ADDR)
-            / TCP(flags="PA", ack=syn_ack.seq + 1, sport=sport, dport=dport)
+            / TCP(
+                flags="PA",
+                sport=sport,
+                dport=dport,
+                seq=seq_init + 1,
+                ack=syn_ack.seq + 1,
+            )
             / Raw("GET / HTTP/1.1\r\n\r\n")
         )
         resp = iface.sr1(req, timeout=1)
         assert resp is not None, "expecting answer, got nothing"
         check_ipv6_checksum(resp)
-        assert TCP in resp
+        assert TCP in resp, "expecting TCP, got %r" % resp.summary()
         tcp = resp[TCP]
         assert tcp.payload.load.startswith(b"HTTP/1.1 401 Unauthorized\n")
 
@@ -553,33 +620,46 @@ def test_ipv4_tcp_http_ko(iface):
     sport = 24592
     dports = [80, 443, 5000, 53228]
     for dport in dports:
+        seq_init = int(RandInt())
         syn = (
             Ether(dst=MAC_ADDR)
             / IP(dst=IPV4_ADDR)
-            / TCP(flags="S", sport=sport, dport=dport)
+            / TCP(flags="S", sport=sport, dport=dport, seq=seq_init)
         )
         syn_ack = iface.sr1(syn, timeout=1)
         assert syn_ack is not None, "expecting answer, got nothing"
         check_ip_checksum(syn_ack)
-        assert TCP in syn_ack
+        assert TCP in syn_ack, "expecting TCP, got %r" % syn_ack.summary()
         syn_ack = syn_ack[TCP]
         assert syn_ack.flags == "SA"
         ack = (
             Ether(dst=MAC_ADDR)
             / IP(dst=IPV4_ADDR)
-            / TCP(flags="A", sport=sport, dport=dport, ack=syn_ack.seq + 1)
+            / TCP(
+                flags="A",
+                sport=sport,
+                dport=dport,
+                seq=seq_init + 1,
+                ack=syn_ack.seq + 1,
+            )
         )
         _ = iface.sr1(ack, timeout=1)
         req = (
             Ether(dst=MAC_ADDR)
             / IP(dst=IPV4_ADDR)
-            / TCP(flags="PA", ack=syn_ack.seq + 1, sport=sport, dport=dport)
+            / TCP(
+                flags="PA",
+                sport=sport,
+                dport=dport,
+                seq=seq_init + 1,
+                ack=syn_ack.seq + 1,
+            )
             / Raw(bytes.fromhex("4f5054494f4e53"))
         )
         resp = iface.sr1(req, timeout=1)
         assert resp is not None, "expecting answer, got nothing"
         check_ip_checksum(resp)
-        assert TCP in resp
+        assert TCP in resp, "expecting TCP, got %r" % resp.summary()
         assert "P" not in resp[TCP].flags
         assert len(resp[TCP].payload) == 0
 
@@ -604,33 +684,46 @@ def test_ipv6_tcp_http_ko(iface):
     sport = 24592
     dports = [80, 443, 5000, 53228]
     for dport in dports:
+        seq_init = int(RandInt())
         syn = (
             Ether(dst=MAC_ADDR)
             / IPv6(dst=IPV6_ADDR)
-            / TCP(flags="S", sport=sport, dport=dport)
+            / TCP(flags="S", sport=sport, dport=dport, seq=seq_init)
         )
         syn_ack = iface.sr1(syn, timeout=1)
         assert syn_ack is not None, "expecting answer, got nothing"
         check_ipv6_checksum(syn_ack)
-        assert TCP in syn_ack
+        assert TCP in syn_ack, "expecting TCP, got %r" % syn_ack.summary()
         syn_ack = syn_ack[TCP]
         assert syn_ack.flags == "SA"
         ack = (
             Ether(dst=MAC_ADDR)
             / IPv6(dst=IPV6_ADDR)
-            / TCP(flags="A", sport=sport, dport=dport, ack=syn_ack.seq + 1)
+            / TCP(
+                flags="A",
+                sport=sport,
+                dport=dport,
+                seq=seq_init + 1,
+                ack=syn_ack.seq + 1,
+            )
         )
         _ = iface.sr1(ack, timeout=1)
         req = (
             Ether(dst=MAC_ADDR)
             / IPv6(dst=IPV6_ADDR)
-            / TCP(flags="PA", ack=syn_ack.seq + 1, sport=sport, dport=dport)
+            / TCP(
+                flags="PA",
+                sport=sport,
+                dport=dport,
+                seq=seq_init + 1,
+                ack=syn_ack.seq + 1,
+            )
             / Raw(bytes.fromhex("4f5054494f4e53"))
         )
         resp = iface.sr1(req, timeout=1)
         assert resp is not None, "expecting answer, got nothing"
         check_ipv6_checksum(resp)
-        assert TCP in resp
+        assert TCP in resp, "expecting TCP, got %r" % resp.summary()
         assert "P" not in resp[TCP].flags
         assert len(resp[TCP].payload) == 0
 
@@ -815,6 +908,7 @@ def test_ipv4_tcp_ssh(iface):
     sport = 37183
     dports = [22, 80, 2222, 2022, 23874, 50000]
     for i, dport in enumerate(dports):
+        seq_init = int(RandInt())
         banner = [
             b"SSH-2.0-AsyncSSH_2.1.0",
             b"SSH-2.0-PuTTY",
@@ -825,30 +919,42 @@ def test_ipv4_tcp_ssh(iface):
         syn = (
             Ether(dst=MAC_ADDR)
             / IP(dst=IPV4_ADDR)
-            / TCP(flags="S", sport=sport, dport=dport)
+            / TCP(flags="S", sport=sport, dport=dport, seq=seq_init)
         )
         syn_ack = iface.sr1(syn, timeout=1)
         assert syn_ack is not None, "expecting answer, got nothing"
         check_ip_checksum(syn_ack)
-        assert TCP in syn_ack
+        assert TCP in syn_ack, "expecting TCP, got %r" % syn_ack.summary()
         syn_ack = syn_ack[TCP]
         assert syn_ack.flags == "SA"
         ack = (
             Ether(dst=MAC_ADDR)
             / IP(dst=IPV4_ADDR)
-            / TCP(flags="A", sport=sport, dport=dport, ack=syn_ack.seq + 1)
+            / TCP(
+                flags="A",
+                sport=sport,
+                dport=dport,
+                seq=seq_init + 1,
+                ack=syn_ack.seq + 1,
+            )
         )
         _ = iface.sr1(ack, timeout=1)
         req = (
             Ether(dst=MAC_ADDR)
             / IP(dst=IPV4_ADDR)
-            / TCP(flags="PA", ack=syn_ack.seq + 1, sport=sport, dport=dport)
+            / TCP(
+                flags="PA",
+                sport=sport,
+                dport=dport,
+                seq=seq_init + 1,
+                ack=syn_ack.seq + 1,
+            )
             / Raw(banner + b"\r\n")
         )
         resp = iface.sr1(req, timeout=1)
         assert resp is not None, "expecting answer, got nothing"
         check_ip_checksum(resp)
-        assert TCP in resp
+        assert TCP in resp, "expecting TCP, got %r" % resp.summary()
         tcp = resp[TCP]
         assert "A" in tcp.flags, "expecting ACK flag, not set (%r)" % tcp.flags
         assert "P" in tcp.flags, "expecting PSH flag, not set (%r)" % tcp.flags
@@ -898,6 +1004,7 @@ def test_ipv6_tcp_ssh(iface):
     sport = 37183
     dports = [22, 80, 2222, 2022, 23874, 50000]
     for i, dport in enumerate(dports):
+        seq_init = int(RandInt())
         banner = [
             b"SSH-2.0-AsyncSSH_2.1.0",
             b"SSH-2.0-PuTTY",
@@ -908,30 +1015,42 @@ def test_ipv6_tcp_ssh(iface):
         syn = (
             Ether(dst=MAC_ADDR)
             / IPv6(dst=IPV6_ADDR)
-            / TCP(flags="S", sport=sport, dport=dport)
+            / TCP(flags="S", sport=sport, dport=dport, seq=seq_init)
         )
         syn_ack = iface.sr1(syn, timeout=1)
         assert syn_ack is not None, "expecting answer, got nothing"
         check_ipv6_checksum(syn_ack)
-        assert TCP in syn_ack
+        assert TCP in syn_ack, "expecting TCP, got %r" % syn_ack.summary()
         syn_ack = syn_ack[TCP]
         assert syn_ack.flags == "SA"
         ack = (
             Ether(dst=MAC_ADDR)
             / IPv6(dst=IPV6_ADDR)
-            / TCP(flags="A", sport=sport, dport=dport, ack=syn_ack.seq + 1)
+            / TCP(
+                flags="A",
+                sport=sport,
+                dport=dport,
+                seq=seq_init + 1,
+                ack=syn_ack.seq + 1,
+            )
         )
         _ = iface.sr1(ack, timeout=1)
         req = (
             Ether(dst=MAC_ADDR)
             / IPv6(dst=IPV6_ADDR)
-            / TCP(flags="PA", ack=syn_ack.seq + 1, sport=sport, dport=dport)
+            / TCP(
+                flags="PA",
+                sport=sport,
+                dport=dport,
+                seq=seq_init + 1,
+                ack=syn_ack.seq + 1,
+            )
             / Raw(banner + b"\r\n")
         )
         resp = iface.sr1(req, timeout=1)
         assert resp is not None, "expecting answer, got nothing"
         check_ipv6_checksum(resp)
-        assert TCP in resp
+        assert TCP in resp, "expecting TCP, got %r" % resp.summary()
         tcp = resp[TCP]
         assert "A" in tcp.flags, "expecting ACK flag, not set (%r)" % tcp.flags
         assert "P" in tcp.flags, "expecting PSH flag, not set (%r)" % tcp.flags