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Date: Fri, 31 Aug 2018 13:07:56 -0700
From: Stephen Hemminger <stephen@networkplumber.org>
To: waqas ahmed <waqasahmed1471@gmail.com>
Cc: users@dpdk.org
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Subject: Re: [dpdk-users] Frame Check Sequence is incorrect?
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On Fri, 31 Aug 2018 23:19:38 +0500
waqas ahmed <waqasahmed1471@gmail.com> wrote:

> Hi Everyone,
> i have kvm with two ports, i am getting rtp stream from port 0 and just
> change source ip of each packet and recalculate ipv4 checksum. then same
> pkt mbuf is got rte_eth_tx_burst from port1.
> but on vm2 wireshark shows that Frame check sequence is incorrect, that
> seems that while getting same mbuf out from port1 cant get FCS
> recalculated? by emulated nic.
> kind regards and any help is appreciated.

 almost all nic's inside a hypervisor do not support getting FCS.

FCS is used when transferring data over physical wires, and really makes
no sense in a virtual environment.