diff --git a/src/eviction_filter/eviction_filter.cpp b/src/eviction_filter/eviction_filter.cpp
index a54ed7b..845c4a4 100644
--- a/src/eviction_filter/eviction_filter.cpp
+++ b/src/eviction_filter/eviction_filter.cpp
@@ -4,7 +4,7 @@
 
 #include "timestamp.h"
 #include "dablooms.h"
-#include "udp_helpers.h"
+#include "udp_utils.h"
 #include "ipv4_helpers.h"
 #include "ipv6_helpers.h"
 #include "eviction_filter.h"
@@ -12,8 +12,8 @@
 struct eviction_filter_key
 {
     // UDP
-    uint16_t src_port; /* network order */
-    uint16_t dst_port; /* network order */
+    uint16_t src_port; /* host order */
+    uint16_t dst_port; /* host order */
 
     // IPv4 or IPv6
     union ip_address src_addr; /* network order */
@@ -77,8 +77,8 @@ static inline int packet_get_eviction_filter_key(const struct packet *packet, st
     }
 
     const struct udphdr *udphdr = (const struct udphdr *)l4_layer->hdr_ptr;
-    key->src_port = udp_hdr_get_net_order_sport(udphdr);
-    key->dst_port = udp_hdr_get_net_order_dport(udphdr);
+    key->src_port = udp_hdr_get_src_port(udphdr);
+    key->dst_port = udp_hdr_get_dst_port(udphdr);
 
     return 0;
 }
diff --git a/src/packet/packet.cpp b/src/packet/packet.cpp
index 7034120..c640a60 100644
--- a/src/packet/packet.cpp
+++ b/src/packet/packet.cpp
@@ -10,6 +10,7 @@
 
 #include "uthash.h"
 #include "packet.h"
+#include "udp_utils.h"
 
 #define likely(expr) __builtin_expect((expr), 1)
 #define unlikely(expr) __builtin_expect((expr), 0)
@@ -865,6 +866,7 @@ static inline const char *parse_ipv4(struct packet *handler, const char *data, u
     if ((ntohs(hdr->ip_off) & IP_MF) || (ntohs(hdr->ip_off) & IP_OFFMASK))
     {
         PACKET_LOG_DEBUG("ip is fragmented");
+        handler->frag_layer = layer;
         return layer->pld_ptr;
     }
 
@@ -888,6 +890,8 @@ static inline const char *parse_ipv6(struct packet *handler, const char *data, u
     uint8_t next_proto = ((struct ip6_hdr *)data)->ip6_nxt;
     SET_LAYER(handler, layer, LAYER_TYPE_IPV6, sizeof(struct ip6_hdr), data, len);
 
+    // TODO ipv6 fragment
+
     // TESTED
     return parse_l4(handler, next_proto, layer->pld_ptr, layer->pld_len);
 }
@@ -945,7 +949,7 @@ static inline const char *parse_udp(struct packet *handler, const char *data, ui
     struct udphdr *hdr = (struct udphdr *)data;
     SET_LAYER(handler, layer, LAYER_TYPE_UDP, sizeof(struct udphdr), data, len);
 
-    switch (ntohs(hdr->uh_dport))
+    switch (udp_hdr_get_dst_port(hdr))
     {
         // TESTED
     // VXLAN_DPORT
@@ -1096,6 +1100,7 @@ static inline const char *parse_l4(struct packet *handler, uint8_t next_proto, c
 // return innermost payload
 const char *packet_parse(struct packet *handler, const char *data, uint16_t len)
 {
+    handler->frag_layer = NULL;
     handler->layers_used = 0;
     handler->layers_size = PACKET_MAX_LAYERS;
     handler->data_ptr = data;
diff --git a/src/packet/packet.h b/src/packet/packet.h
index 584c28a..ec61ac1 100644
--- a/src/packet/packet.h
+++ b/src/packet/packet.h
@@ -74,6 +74,7 @@ struct layer_record
 struct packet
 {
     struct layer_record layers[PACKET_MAX_LAYERS];
+    struct layer_record *frag_layer; // fragment layer
     int8_t layers_used;
     int8_t layers_size;
 
diff --git a/src/packet/test/CMakeLists.txt b/src/packet/test/CMakeLists.txt
index 43de4df..798f514 100644
--- a/src/packet/test/CMakeLists.txt
+++ b/src/packet/test/CMakeLists.txt
@@ -5,8 +5,8 @@
 add_executable(gtest_packet gtest_packet.cpp)
 target_link_libraries(gtest_packet packet gtest)
 
-add_executable(gtest_udp_helpers gtest_udp_helpers.cpp)
-target_link_libraries(gtest_udp_helpers packet gtest)
+add_executable(gtest_udp_utils gtest_udp_utils.cpp)
+target_link_libraries(gtest_udp_utils packet gtest)
 
 add_executable(gtest_tcp_helpers gtest_tcp_helpers.cpp)
 target_link_libraries(gtest_tcp_helpers packet gtest)
@@ -22,7 +22,7 @@ target_link_libraries(gtest_packet_helpers packet gtest)
 
 include(GoogleTest)
 gtest_discover_tests(gtest_packet)
-gtest_discover_tests(gtest_udp_helpers)
+gtest_discover_tests(gtest_udp_utils)
 gtest_discover_tests(gtest_tcp_helpers)
 gtest_discover_tests(gtest_ipv4_helpers)
 gtest_discover_tests(gtest_ipv6_helpers)
diff --git a/src/packet/test/gtest_udp_helpers.cpp b/src/packet/test/gtest_udp_utils.cpp
similarity index 53%
rename from src/packet/test/gtest_udp_helpers.cpp
rename to src/packet/test/gtest_udp_utils.cpp
index 000ec73..62dbc81 100644
--- a/src/packet/test/gtest_udp_helpers.cpp
+++ b/src/packet/test/gtest_udp_utils.cpp
@@ -1,6 +1,6 @@
 #include <gtest/gtest.h>
 
-#include "udp_helpers.h"
+#include "udp_utils.h"
 
 /*
  * User Datagram Protocol, Src Port: 4001, Dst Port: 8000
@@ -14,15 +14,28 @@
 
 unsigned char data[] = {0x0f, 0xa1, 0x1f, 0x40, 0x00, 0x9b, 0x1e, 0x1e};
 
-TEST(UDP_HELPERS, TEST)
+TEST(UDP_UTILS, GET)
 {
     const struct udphdr *hdr = (struct udphdr *)data;
-    EXPECT_TRUE(udp_hdr_get_host_order_sport(hdr) == 4001);
-    EXPECT_TRUE(udp_hdr_get_host_order_dport(hdr) == 8000);
-    EXPECT_TRUE(udp_hdr_get_len(hdr) == 155);
+
+    EXPECT_TRUE(udp_hdr_get_src_port(hdr) == 4001);
+    EXPECT_TRUE(udp_hdr_get_dst_port(hdr) == 8000);
+    EXPECT_TRUE(udp_hdr_get_total_len(hdr) == 155);
     EXPECT_TRUE(udp_hdr_get_checksum(hdr) == 0x1e1e);
 }
 
+TEST(UDP_UTILS, SET)
+{
+    char buff[8] = {0};
+    struct udphdr *hdr = (struct udphdr *)buff;
+
+    udp_hdr_set_src_port(hdr, 4001);
+    udp_hdr_set_dst_port(hdr, 8000);
+    udp_hdr_set_total_len(hdr, 155);
+    udp_hdr_set_checksum(hdr, 0x1e1e);
+    EXPECT_TRUE(memcmp(buff, data, 8) == 0);
+}
+
 int main(int argc, char **argv)
 {
     ::testing::InitGoogleTest(&argc, argv);
diff --git a/src/packet/udp_helpers.h b/src/packet/udp_utils.h
similarity index 50%
rename from src/packet/udp_helpers.h
rename to src/packet/udp_utils.h
index 424d297..600f216 100644
--- a/src/packet/udp_helpers.h
+++ b/src/packet/udp_utils.h
@@ -1,5 +1,5 @@
-#ifndef _UDP_HELPERS_H
-#define _UDP_HELPERS_H
+#ifndef _UDP_UTILS_H
+#define _UDP_UTILS_H
 
 #ifdef __cpluscplus
 extern "C"
@@ -24,27 +24,21 @@ extern "C"
  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  */
 
-static inline uint16_t udp_hdr_get_host_order_sport(const struct udphdr *hdr)
+/******************************************************************************
+ * get
+ ******************************************************************************/
+
+static inline uint16_t udp_hdr_get_src_port(const struct udphdr *hdr)
 {
     return ntohs(hdr->uh_sport);
 }
 
-static inline uint16_t udp_hdr_get_host_order_dport(const struct udphdr *hdr)
+static inline uint16_t udp_hdr_get_dst_port(const struct udphdr *hdr)
 {
     return ntohs(hdr->uh_dport);
 }
 
-static inline uint16_t udp_hdr_get_net_order_sport(const struct udphdr *hdr)
-{
-    return hdr->uh_sport;
-}
-
-static inline uint16_t udp_hdr_get_net_order_dport(const struct udphdr *hdr)
-{
-    return hdr->uh_dport;
-}
-
-static inline uint16_t udp_hdr_get_len(const struct udphdr *hdr)
+static inline uint16_t udp_hdr_get_total_len(const struct udphdr *hdr)
 {
     return ntohs(hdr->uh_ulen);
 }
@@ -54,6 +48,30 @@ static inline uint16_t udp_hdr_get_checksum(const struct udphdr *hdr)
     return ntohs(hdr->uh_sum);
 }
 
+/******************************************************************************
+ * set
+ ******************************************************************************/
+
+static inline void udp_hdr_set_src_port(struct udphdr *hdr, uint16_t port)
+{
+    hdr->uh_sport = htons(port);
+}
+
+static inline void udp_hdr_set_dst_port(struct udphdr *hdr, uint16_t port)
+{
+    hdr->uh_dport = htons(port);
+}
+
+static inline void udp_hdr_set_total_len(struct udphdr *hdr, uint16_t len)
+{
+    hdr->uh_ulen = htons(len);
+}
+
+static inline void udp_hdr_set_checksum(struct udphdr *hdr, uint16_t sum)
+{
+    hdr->uh_sum = htons(sum);
+}
+
 #ifdef __cpluscplus
 }
 #endif