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 <[email protected]> > Sent: Thursday, 17 March 2022 20:21 > To: Ido Goshen <[email protected]> > Cc: Ferruh Yigit <[email protected]>; [email protected] > Subject: Re: [PATCH] net/pcap: support MTU set > > On Thu, 17 Mar 2022 19:43:47 +0200 > ido g <[email protected]> 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.
