Hello,
Enviroment information;
DPDK versiyon 17.05
Kernel version 4.4.0
OS - Ubuntu 16.05
INTEL NIC XL710
Last i40e driver and NVM is installed.
ethtool -k ens2f2 :
tx-checksumming: on
tx-checksum-ipv4: on
tx-checksum-ip-generic: off [fixed]
tx-checksum-ipv6: on
tx-checksum-fcoe-crc: off [fixed]
tx-checksum-sctp: on
rx-fcs: off [fixed]
rx-all: off [fixed]
What is CRC or FCS :
https://www.firewall.cx/networking-topics/ethernet/ethernet-frame-formats/201-ethernet-ii.html
State:
* Even if strip_crc flag is up in port_config, NIC doesnt strip CRC.
* After stripping Ethernet Header from message-buf, CRC still there. So it
breaks fragmentation when specific byte length income. For Example; Message
with IP header -> 1480, Ether Header 6+6+2 = 14 byte. Frame length looks 1498
byte. Looks like 4 byte Crc, it has. After Ether header is stripped , 1488
byte left.
[code]
static struct rte_eth_conf port_conf = {
.rxmode =
{
.header_split = 0, /* Header Split disabled */
.hw_ip_checksum = 0, /* IP checksum offload disabled */
.hw_vlan_filter = 0, /* VLAN filtering disabled */
.jumbo_frame = 0, /* Jumbo Frame Support disabled */
.hw_strip_crc = 1, /* CRC stripped by hardware */
},
.txmode =
{
.mq_mode = ETH_MQ_TX_NONE,
},
};
[/code]
Is there any function to strip CRC bytes or what is best way? Big thanks to
help.
I have an idea that,
After stripping Ethernet Header ,
* If total length of message is bigger than IP header length , there is a
CRC, it needs to strip somehow?
* If total length of message is equal to IP header length, no problem.
* If total length of message is less than IP header length, message is
broken.
Best Regards.
___
Yasin CANER
Lider Mühendis
Ulak Haberleşme A.Ş. Ankara
