How to Enable ip Fragmentation about dpdk-ans HOT 4 CLOSED

The max IP fragmentaion is defined in DPDK.
What is ans verson do you use? Your version is very old.
Shall use ans_iface_set_mtu to set MTU.

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Thanks for the quick answering.

(I'm using the latest version. I saw old API netdp*** at the old issue in 2016.)

For the fragmentation,
I ran DPDK IP fragmentation example and it well fragments packet as its MTU configured.

As I know, IP fragmentation is not a sort of EAL option but can be enabled by related API like 'rte_ip_frag.h->rte_ipv4_fragment_packet()'.

Following the ans.map file, 'rte_ip_frag.h' and 'rte_ipv4_fragment_packet()' are already imported and used.

Also anscli shows mtu is set as 1500, in below
ans> ip addr show veth0: mtu 1500

Then what I anticipate is that, 5800B data should be fragmented to 1500B size and sent.

But it doesn't as shown anscli stats

ans> ip stats show
Total packets received :7448
Checksum bad :0
Packet too short :0
Not enough data :0
IP header length < data size :0
IP length < ip header length :0
Fragments received :0
Frags dropped (dups, out of space) :0
Fragments timed out :0
Packets forwarded :2320
Packets fast forwarded :0
Packets rcvd for unreachable dest :0
Packets forwarded on same net :2320
Unknown or unsupported protocol :0
Datagrams delivered to upper level :5128
Total ip packets generated here :3608
Lost packets due to nobufs, etc. :0
Total packets reassembled ok :0
Datagrams successfully fragmented :0
Output fragments created :0
Don't fragment flag was set, etc. :0
Error in option processing :0
Packets discarded due to no route :0
IP version != 4 :0
Total raw ip packets generated :0
IP length > max ip packet size :0
Multicasts for unregistered grps :0
No match gif found :0
Invalid address on header :0
Packets filtered :0

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The limitaion in DPDK:
/* ip_fragmentation defines */
#define RTE_LIBRTE_IP_FRAG_MAX_FRAG 4

You may try 3000B.

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Oh Thanks very much for your answer.

IP Fragmentation is actually works at 5800B, for exactly up to 5912B packet Send.
5912B = (1514(mtu)-34(header) ) * 4(max frag) - 8(udp header of reassembled packet)

Wireshark shows UDP+ IPv4 packets are well fragmented up to 1514.
but anscli only shows stats about Frags only when there are drops, like below::

//when send more then mtu*maxFrag
Frags dropped (dups, out of space) :1816

//when recv kernel dump shows ip fragmented well but cli is not.
Datagrams successfully fragmented :0
Output fragments created :0

It's all clear about IP fragmentation.
Thanks for your help again!

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