diff --git a/flow_db.c b/flow_db.c
index 2a7a82b..b2b9971 100644
--- a/flow_db.c
+++ b/flow_db.c
@@ -96,6 +96,10 @@ static unsigned int hash_5tuple(struct af_6tuple af_6tuple)
 				hash1 = hashf(&af_6tuple.ip1.v4, 4, hash1);
 				hash1 = hashf(&af_6tuple.ip2.v4, 4, hash1);
 				break;
+			case AF_INET6:
+				hash1 = hashf(&af_6tuple.ip1.v6, 16, hash1);
+				hash1 = hashf(&af_6tuple.ip2.v6, 16, hash1);
+				break;
 			}
 			if (af_6tuple.port1)
 				hash1 = hashf(&af_6tuple.port1, 2, hash1);
@@ -107,6 +111,10 @@ static unsigned int hash_5tuple(struct af_6tuple af_6tuple)
 				hash2 = hashf(&af_6tuple.ip2.v4, 4, hash2);
 				hash2 = hashf(&af_6tuple.ip1.v4, 4, hash2);
 				break;
+			case AF_INET6:
+				hash2 = hashf(&af_6tuple.ip2.v6, 16, hash2);
+				hash2 = hashf(&af_6tuple.ip1.v6, 16, hash2);
+				break;
 			}
 			if (af_6tuple.port2)
 				hash2 = hashf(&af_6tuple.port2, 2, hash2);
@@ -137,6 +145,16 @@ static int compare_5tuple(struct af_6tuple af1, struct af_6tuple af2)
 		    af1.port1 == af2.port2 && af1.port2 == af2.port1)
 			return 1;
 		break;
+	case AF_INET6:
+		if (memcmp(&af1.ip1.v6, &af2.ip1.v6, sizeof(af1.ip1.v6)) == 0 &&
+		    memcmp(&af1.ip2.v6, &af2.ip2.v6, sizeof(af1.ip2.v6)) == 0 &&
+		    af1.port1 == af2.port1 && af1.port2 == af2.port2)
+			return 1;
+		if (memcmp(&af1.ip1.v6, &af2.ip2.v6, sizeof(af1.ip1.v6)) == 0 &&
+		    memcmp(&af1.ip2.v6, &af2.ip1.v6, sizeof(af1.ip2.v6)) == 0 &&
+		    af1.port1 == af2.port2 && af1.port2 == af2.port1)
+			return 1;
+		break;
 	}
 
 	return 0;
diff --git a/pkt2flow.c b/pkt2flow.c
index 12d5304..6b59451 100644
--- a/pkt2flow.c
+++ b/pkt2flow.c
@@ -33,7 +33,9 @@
 #include <getopt.h>
 #include <net/ethernet.h>
 #include <netinet/in.h>
+#include <netinet/in.h>
 #include <netinet/ip.h>
+#include <netinet/ip6.h>
 #include <netinet/tcp.h>
 #include <netinet/udp.h>
 #include <pcap/pcap.h>
@@ -241,6 +243,60 @@ static int pcap_handle_ipv4(struct af_6tuple *af_6tuple, const u_char *bytes,
 	return pcap_handle_layer4(af_6tuple, bytes, len, iphdr->ip_p);
 }
 
+static int pcap_handle_ipv6(struct af_6tuple *af_6tuple, const u_char *bytes,
+			     size_t len)
+{
+	struct ip6_hdr *iphdr;
+	struct ip6_opt *opthdr;
+	int curheader = 255;
+	uint8_t nexthdr;
+
+	while (1) {
+		switch (curheader) {
+		case 255:
+			if (len < sizeof(*iphdr))
+				return -1;
+			iphdr = (struct ip6_hdr *)bytes;
+			bytes += sizeof(*iphdr);
+			len -= sizeof(*iphdr);
+			nexthdr = iphdr->ip6_ctlun.ip6_un1.ip6_un1_nxt;
+
+			af_6tuple->af_family = AF_INET6;
+			af_6tuple->ip1.v6 = iphdr->ip6_src;
+			af_6tuple->ip2.v6 = iphdr->ip6_dst;
+			break;
+		case IPPROTO_HOPOPTS:
+		case IPPROTO_ROUTING:
+		case IPPROTO_DSTOPTS:
+			if (len < sizeof(*opthdr))
+				return -1;
+			nexthdr = bytes[0];
+
+			opthdr = (struct ip6_opt *)bytes;
+			if (len < ((1u + opthdr->ip6o_len) * 8u))
+				return -1;
+			bytes += (1u + opthdr->ip6o_len) * 8u;
+			len -= (1u + opthdr->ip6o_len) * 8u;
+			break;
+		case IPPROTO_FRAGMENT:
+			if (len < 1)
+				return -1;
+			nexthdr = bytes[0];
+			if (len < 8)
+				return -1;
+			bytes += 8;
+			len -= 8;
+			break;
+		case IPPROTO_NONE:
+			return -1;
+		default:
+			return pcap_handle_layer4(af_6tuple, bytes, len,
+						  nexthdr);
+		};
+		curheader = nexthdr;
+	}
+}
+
 static int pcap_handle_ip(struct af_6tuple *af_6tuple, const u_char *bytes,
 			  size_t len)
 {
@@ -251,6 +307,9 @@ static int pcap_handle_ip(struct af_6tuple *af_6tuple, const u_char *bytes,
 	if ((bytes[0] >> 4) == 4)
 		return pcap_handle_ipv4(af_6tuple, bytes, len);
 
+	if ((bytes[0] >> 4) == 6)
+		return pcap_handle_ipv6(af_6tuple, bytes, len);
+
 	return -1;
 }
 
@@ -269,7 +328,8 @@ static int pcap_handle_ethernet(struct af_6tuple *af_6tuple,
 	len -= sizeof(*ethhdr);
 	bytes += sizeof(*ethhdr);
 
-	if (ntohs(ethhdr->ether_type) != ETHERTYPE_IP)
+	if (ntohs(ethhdr->ether_type) != ETHERTYPE_IP &&
+	    ntohs(ethhdr->ether_type) != ETHERTYPE_IPV6)
 		return -1;
 
 	return pcap_handle_ip(af_6tuple, bytes, len);
diff --git a/pkt2flow.h b/pkt2flow.h
index ef9bd05..5663e9b 100644
--- a/pkt2flow.h
+++ b/pkt2flow.h
@@ -33,6 +33,7 @@
 
 #include <stdint.h>
 #include <netinet/in.h>
+#include <netinet/ip6.h>
 
 #define __SOURCE_VERSION__              "1.2"
 #define __AUTHOR__                      "X. Chen (chenxm35@gmail.com)"
@@ -68,6 +69,7 @@ struct pkt_dump_file {
 
 union ip_address {
 	struct in_addr v4;
+	struct in6_addr v6;
 };
 
 struct af_6tuple {
diff --git a/utilities.c b/utilities.c
index fe89dac..1911297 100644
--- a/utilities.c
+++ b/utilities.c
@@ -41,8 +41,8 @@
 char *new_file_name(struct af_6tuple af_6tuple, unsigned long timestamp)
 {
 	char *fname;
-	char src_ip_str[INET_ADDRSTRLEN];
-	char dst_ip_str[INET_ADDRSTRLEN];
+	char src_ip_str[INET6_ADDRSTRLEN];
+	char dst_ip_str[INET6_ADDRSTRLEN];
 	int ret;
 
 	switch (af_6tuple.af_family) {
@@ -50,6 +50,10 @@ char *new_file_name(struct af_6tuple af_6tuple, unsigned long timestamp)
 		inet_ntop(AF_INET, &af_6tuple.ip1.v4, src_ip_str, INET_ADDRSTRLEN);
 		inet_ntop(AF_INET, &af_6tuple.ip2.v4, dst_ip_str, INET_ADDRSTRLEN);
 		break;
+	case AF_INET6:
+		inet_ntop(AF_INET6, &af_6tuple.ip1.v6, src_ip_str, INET6_ADDRSTRLEN);
+		inet_ntop(AF_INET6, &af_6tuple.ip2.v6, dst_ip_str, INET6_ADDRSTRLEN);
+		break;
 	}
 
 	ret = asprintf(&fname, "%s_%"PRIu16"_%s_%"PRIu16"_%lu.pcap",