[dpdk-dev] ixgbe tcp cksum offload

Tim Deng dpdkdev at 126.com
Mon May 25 12:15:23 CEST 2015


Hi,


I am trying to use ixgbe tcp cksum h/w offload by following steps:
- populate pseudo cksum
- set l2_len, l3_len, l4_len
- set ol_flags


But I found the pkt doesn't get right h/w checksum by sniffing on recv side, and TCP cksum still leave with the original pseudo cksum. 
And I verified those meta are correctly set, e.g. a TCP syn pkt:
l2_len = 14, l3_len = 20, l4_len = 40 (with some tcp options),
and ol_flags = 0x90000000000000 which means PKT_TX_IPV4 | PKT_TX_TCP_CKSUM


Did I miss any step?


Thanks in advance,
Tim



More information about the dev mailing list