diff --git a/src/packet/test/gtest_packet_build.cpp b/src/packet/test/gtest_packet_build.cpp
index 5684219..d212ba0 100644
--- a/src/packet/test/gtest_packet_build.cpp
+++ b/src/packet/test/gtest_packet_build.cpp
@@ -168,6 +168,124 @@ TEST(PACKET_BUILD, ETH_IP4_TCP)
 }
 #endif
 
+/******************************************************************************
+ * [Protocols in frame: eth:ethertype:ip:ipv6:tcp]
+ ******************************************************************************
+ *
+ * Frame 1: 106 bytes on wire (848 bits), 106 bytes captured (848 bits)
+ * Ethernet II, Src: JuniperN_45:88:29 (2c:6b:f5:45:88:29), Dst: JuniperN_2a:a2:00 (5c:5e:ab:2a:a2:00)
+ *  Destination: JuniperN_2a:a2:00 (5c:5e:ab:2a:a2:00)
+ *  Source: JuniperN_45:88:29 (2c:6b:f5:45:88:29)
+ *  Type: IPv4 (0x0800)
+ * Internet Protocol Version 4, Src: 210.77.88.163, Dst: 59.66.4.50
+ *  0100 .... = Version: 4
+ *  .... 0101 = Header Length: 20 bytes (5)
+ *  Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
+ *  Total Length: 92
+ *  Identification: 0x0b4d (2893)
+ *  000. .... = Flags: 0x0
+ *  ...0 0000 0000 0000 = Fragment Offset: 0
+ *  Time to Live: 59
+ *  Protocol: IPv6 (41)
+ *  Header Checksum: 0x09c8 [validation disabled]
+ *  [Header checksum status: Unverified]
+ *  Source Address: 210.77.88.163
+ *  Destination Address: 59.66.4.50
+ * Internet Protocol Version 6, Src: 2001:da8:200:900e:200:5efe:d24d:58a3, Dst: 2600:140e:6::1702:1058
+ *  0110 .... = Version: 6
+ *  .... 0000 0000 .... .... .... .... .... = Traffic Class: 0x00 (DSCP: CS0, ECN: Not-ECT)
+ *  .... 0000 0000 0000 0000 0000 = Flow Label: 0x00000
+ *  Payload Length: 32
+ *  Next Header: TCP (6)
+ *  Hop Limit: 64
+ *  Source Address: 2001:da8:200:900e:200:5efe:d24d:58a3
+ *  Destination Address: 2600:140e:6::1702:1058
+ *  [Source ISATAP IPv4: 210.77.88.163]
+ * Transmission Control Protocol, Src Port: 52556, Dst Port: 80, Seq: 0, Len: 0
+ *  Source Port: 52556
+ *  Destination Port: 80
+ *  [Stream index: 0]
+ *  [Conversation completeness: Complete, WITH_DATA (31)]
+ *  [TCP Segment Len: 0]
+ *  Sequence Number: 0    (relative sequence number)
+ *  Sequence Number (raw): 2172673142
+ *  [Next Sequence Number: 1    (relative sequence number)]
+ *  Acknowledgment Number: 0
+ *  Acknowledgment number (raw): 0
+ *  1000 .... = Header Length: 32 bytes (8)
+ *  Flags: 0x002 (SYN)
+ *  Window: 8192
+ *  [Calculated window size: 8192]
+ *  Checksum: 0xf757 [unverified]
+ *  [Checksum Status: Unverified]
+ *  Urgent Pointer: 0
+ *  Options: (12 bytes), Maximum segment size, No-Operation (NOP), Window scale, No-Operation (NOP), No-Operation (NOP), SACK permitted
+ *  [Timestamps]
+ */
+
+unsigned char data2[] = {
+	0x5c, 0x5e, 0xab, 0x2a, 0xa2, 0x00, 0x2c, 0x6b, 0xf5, 0x45, 0x88, 0x29, 0x08, 0x00, 0x45, 0x00, 0x00, 0x5c, 0x0b, 0x4d, 0x00, 0x00, 0x3b, 0x29, 0x09, 0xc8,
+	0xd2, 0x4d, 0x58, 0xa3, 0x3b, 0x42, 0x04, 0x32, 0x60, 0x00, 0x00, 0x00, 0x00, 0x20, 0x06, 0x40, 0x20, 0x01, 0x0d, 0xa8, 0x02, 0x00, 0x90, 0x0e, 0x02, 0x00,
+	0x5e, 0xfe, 0xd2, 0x4d, 0x58, 0xa3, 0x26, 0x00, 0x14, 0x0e, 0x00, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x17, 0x02, 0x10, 0x58, 0xcd, 0x4c, 0x00, 0x50,
+	0x81, 0x80, 0x5c, 0x76, 0x00, 0x00, 0x00, 0x00, 0x80, 0x02, 0x20, 0x00, 0xf7, 0x57, 0x00, 0x00, 0x02, 0x04, 0x04, 0xc4, 0x01, 0x03, 0x03, 0x08, 0x01, 0x01,
+	0x04, 0x02};
+
+/*
+ * imitate_tcp_packet()
+ * 	-> ETH->IPv4->IPv6->TCP
+ *	-> with TCP payload
+ */
+#if 1
+TEST(PACKET_BUILD, ETH_IP4_IP6_TCP)
+{
+	struct packet orig_pkt;
+	memset(&orig_pkt, 0, sizeof(orig_pkt));
+	packet_parse(&orig_pkt, (const char *)data2, sizeof(data2));
+	PRINT_GREEN("origin packet:");
+	packet_print(&orig_pkt);
+
+	struct packet *new_pkt = imitate_tcp_packet(&orig_pkt, 1234, 2345, TH_ACK, NULL, 0, "Hello", 5);
+	EXPECT_TRUE(new_pkt != nullptr);
+	PRINT_GREEN("new packet:");
+	packet_print(new_pkt);
+
+	packet_dump_hex(new_pkt, STDOUT_FILENO);
+	packet_dump_pcap(new_pkt, "imitate-eth-ipv4-ipv6-tcp.pcap");
+
+	const char *orig_pkt_data = packet_get_raw_data(&orig_pkt);
+	uint16_t orig_pkt_len = packet_get_raw_len(&orig_pkt);
+
+	const char *new_pkt_data = packet_get_raw_data(new_pkt);
+	uint16_t new_pkt_len = packet_get_raw_len(new_pkt);
+
+	EXPECT_TRUE(orig_pkt_len - 12 == // trim TCP options
+				new_pkt_len - 5		 // trim TCP payload
+	);
+	for (uint16_t i = 0; i < new_pkt_len - 5; i++)
+	{
+		if ((16 <= i && i <= 17) || // skip IPv4 total length
+			(18 <= i && i <= 19) || // skip IPv4 identification
+			i == 22 ||				// skip IPv4 TTL
+			(24 <= i && i <= 25) || // skip IPv4 checksum
+			(38 <= i && i <= 39) || // skip IPv6 payload length
+			i == 41 ||				// skip IPv6 hop limit
+			(78 <= i && i <= 81) || // skip TCP seq
+			(82 <= i && i <= 85) || // skip TCP ack
+			i == 86 ||				// skip TCP data offset
+			i == 87 ||				// skip TCP flags
+			(88 <= i && i <= 89) || // skip TCP window
+			(90 <= i && i <= 91)	// skip TCP checksum
+		)
+		{
+			continue;
+		}
+
+		// printf(("idx: %d, orig: %02x, new: %02x\n"), i, orig_pkt_data[i], new_pkt_data[i]);
+		EXPECT_TRUE(orig_pkt_data[i] == new_pkt_data[i]);
+	}
+}
+#endif
+
 int main(int argc, char **argv)
 {
 	::testing::InitGoogleTest(&argc, argv);