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SPDX-License-Identifier: BSD-3-Clause 2 Copyright(c) 2010-2014 Intel Corporation. 3 4IP Fragmentation Sample Application 5=================================== 6 7The IPv4 Fragmentation application is a simple example of packet processing 8using the Data Plane Development Kit (DPDK). 9The application does L3 forwarding with IPv4 and IPv6 packet fragmentation. 10 11Overview 12-------- 13 14The application demonstrates the use of zero-copy buffers for packet fragmentation. 15The initialization and run-time paths are very similar to those of the :doc:`l2_forward_real_virtual`. 16This guide highlights the differences between the two applications. 17 18There are three key differences from the L2 Forwarding sample application: 19 20* The first difference is that the IP Fragmentation sample application makes use of indirect buffers. 21 22* The second difference is that the forwarding decision is taken 23 based on information read from the input packet's IP header. 24 25* The third difference is that the application differentiates between 26 IP and non-IP traffic by means of offload flags. 27 28The Longest Prefix Match (LPM for IPv4, LPM6 for IPv6) table is used to store/lookup an outgoing port number, 29associated with that IP address. 30Any unmatched packets are forwarded to the originating port. 31 32By default, input frame sizes up to 9.5 KB are supported. 33Before forwarding, the input IP packet is fragmented to fit into the "standard" Ethernet* v2 MTU (1500 bytes). 34 35Compiling the Application 36------------------------- 37 38To compile the sample application see :doc:`compiling`. 39 40The application is located in the ``ip_fragmentation`` sub-directory. 41 42Running the Application 43----------------------- 44 45The LPM object is created and loaded with the pre-configured entries read from 46global l3fwd_ipv4_route_array and l3fwd_ipv6_route_array tables. 47For each input packet, the packet forwarding decision 48(that is, the identification of the output interface for the packet) is taken as a result of LPM lookup. 49If the IP packet size is greater than default output MTU, 50then the input packet is fragmented and several fragments are sent via the output interface. 51 52Application usage: 53 54.. code-block:: console 55 56 ./<build_dir>/examples/dpdk-ip_fragmentation [EAL options] -- -p PORTMASK [-q NQ] 57 58where: 59 60* -p PORTMASK is a hexadecimal bitmask of ports to configure 61 62* -q NQ: Maximum number of queues per lcore (default is 1) 63 64To run the example in linux environment with 2 lcores (2,4) over 2 ports(0,2) with 1 RX queue per lcore: 65 66.. code-block:: console 67 68 ./<build_dir>/examples/dpdk-ip_fragmentation -l 2,4 -n 3 -- -p 5 69 EAL: coremask set to 14 70 EAL: Detected lcore 0 on socket 0 71 EAL: Detected lcore 1 on socket 1 72 EAL: Detected lcore 2 on socket 0 73 EAL: Detected lcore 3 on socket 1 74 EAL: Detected lcore 4 on socket 0 75 ... 76 77 Initializing port 0 on lcore 2... Address:00:1B:21:76:FA:2C, rxq=0 txq=2,0 txq=4,1 78 done: Link Up - speed 10000 Mbps - full-duplex 79 Skipping disabled port 1 80 Initializing port 2 on lcore 4... Address:00:1B:21:5C:FF:54, rxq=0 txq=2,0 txq=4,1 81 done: Link Up - speed 10000 Mbps - full-duplex 82 Skipping disabled port 3IP_FRAG: Socket 0: adding route 100.10.0.0/16 (port 0) 83 IP_FRAG: Socket 0: adding route 100.20.0.0/16 (port 1) 84 ... 85 IP_FRAG: Socket 0: adding route 0101:0101:0101:0101:0101:0101:0101:0101/48 (port 0) 86 IP_FRAG: Socket 0: adding route 0201:0101:0101:0101:0101:0101:0101:0101/48 (port 1) 87 ... 88 IP_FRAG: entering main loop on lcore 4 89 IP_FRAG: -- lcoreid=4 portid=2 90 IP_FRAG: entering main loop on lcore 2 91 IP_FRAG: -- lcoreid=2 portid=0 92 93To run the example in linux environment with 1 lcore (4) over 2 ports(0,2) with 2 RX queues per lcore: 94 95.. code-block:: console 96 97 ./<build_dir>/examples/dpdk-ip_fragmentation -l 4 -n 3 -- -p 5 -q 2 98 99To test the application, flows should be set up in the flow generator that match the values in the 100l3fwd_ipv4_route_array and/or l3fwd_ipv6_route_array table. 101 102The default l3fwd_ipv4_route_array table is: 103 104.. literalinclude:: ../../../examples/ip_fragmentation/main.c 105 :language: c 106 :start-after: Default l3fwd_ipv4_route_array table. 8< 107 :end-before: >8 End of default l3fwd_ipv4_route_array table 108 109The default l3fwd_ipv6_route_array table is: 110 111.. literalinclude:: ../../../examples/ip_fragmentation/main.c 112 :language: c 113 :start-after: Default l3fwd_ipv6_route_array table. 8< 114 :end-before: >8 End of default l3fwd_ipv6_route_array table. 115 116For example, for the input IPv4 packet with destination address: 100.10.1.1 and packet length 9198 bytes, 117seven IPv4 packets will be sent out from port #0 to the destination address 100.10.1.1: 118six of those packets will have length 1500 bytes and one packet will have length 318 bytes. 119IP Fragmentation sample application provides basic NUMA support 120in that all the memory structures are allocated on all sockets that have active lcores on them. 121 122 123Refer to the *DPDK Getting Started Guide* for general information on running applications 124and the Environment Abstraction Layer (EAL) options. 125