As far as I can see the initial device MTU is derived from port *RX*
configuration in struct rte_eth_rxmode
https://doc.dpdk.org/api-21.11/structrte__eth__rxmode.html
Couple of real NICs I've tested (ixgbe, i40e based) don't allow oversized,
tests details can be seen in https://bugs.dpdk.org/show_bug.cgi?id=961
> -----Original Message-----
> From: Stephen Hemminger <step...@networkplumber.org>
> Sent: Thursday, 17 March 2022 20:21
> To: Ido Goshen <i...@cgstowernetworks.com>
> Cc: Ferruh Yigit <ferruh.yi...@intel.com>; dev@dpdk.org
> Subject: Re: [PATCH] net/pcap: support MTU set
>
> On Thu, 17 Mar 2022 19:43:47 +0200
> ido g <i...@cgstowernetworks.com> wrote:
>
> > + if (unlikely(header.caplen > dev->data->mtu)) {
> > + pcap_q->rx_stat.err_pkts++;
> > + rte_pktmbuf_free(mbuf);
> > + break;
> > + }
>
> MTU should only be enforced on transmit.
> Other real network devices allow oversized packets.
>
> Since the pcap file is something user provides, if you don't want that then
> use
> something to filter the file.
