I have observed that fragmenting a IPv4 UDP packet using dpdk rte_ipv4_fragment_packet() generates 2 packets as expected. When reassembling using rte_ipv4_frag_reassemble_packet() the end of the reassembled packet is all zeros. The zeros are the length of the data part of the second fragment. The same result was obtained using dpdk-20.08.0 and dpdk-20.11.0 (LTS) versions. Running CentOS-8.2.2004-x86_64 on Intel C3758 with 16G ram, 4x 1G hugepages dpdk-20.08.0 had kernel 4.18.0-193.19.1.el8_2.x86_64 dpdk-20.11.0 has kernel 4.18.0-240.1.1.el8_3.x86_64 Subset below of reassembly code involved with some constants replaced and error checking removed to simplify. Packets are read in burst of 32 max and code is typical of examples running polled mode. The fragment table is only updated from the workingThread(), the table is global so rte_ip_frag_table_statistics_dump(stdout, fragReassambleTblWan) can be called outside workingThread() for testing. The Wireshark capture was using dpdk-20.11.0 and is between 2 identical C3758 boxes, one fragmenting and the other doing reassembly, summarized below. static struct rte_mempool *pktmbuf_pool = NULL; struct rte_ip_frag_tbl *fragReassambleTblWan; Main() socket_id = rte_socket_id(); pktmbuf_pool = rte_pktmbuf_pool_create("mbuf_pool", 131072, 256, 0, (2048+128), socket_id); workingThread() uint64_t tms; uint64_t fragCycles; struct rte_ether_hdr *ethhdr; struct rte_ipv4_hdr *iphdr4; struct rte_mbuf *m; struct rte_mbuf *mx; struct rte_ip_frag_death_row deathRow; memset(&deathRow, 0, sizeof(deathRow)); fragCycles = (rte_get_tsc_hz() + MS_PER_S - 1) / MS_PER_S * (8 * MS_PER_S); lcore_id = rte_lcore_id(); socketFrag = rte_lcore_to_socket_id(lcore_id); fragReassambleTblWan = rte_ip_frag_table_create(4096, 4, 4096, fragCycles, socketFrag) workingThread() processing loop for each packet tms = rte_rdtsc(); ethhdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *); iphdr4 = (struct rte_ipv4_hdr *) RTE_PTR_ADD(ethhdr, sizeof(struct rte_ether_hdr)); if (rte_ipv4_frag_pkt_is_fragmented(iphdr4)) { m->l2_len = sizeof(*ethhdr); m->l3_len = sizeof(*iphdr4); mx = rte_ipv4_frag_reassemble_packet(fragReassambleTblWan, &deathRow, m, tms, iphdr4); } rte_ip_frag_free_death_row(&deathRow, 0); mx is NULL on first fragment packet as expected. Second fragment and mx is non-NULL and contains reassembled but end of packet with zeros. Thank you in advance for your help Roy