>From: Nitin Katiyar [mailto:nitin.kati...@ericsson.com] >Sent: Monday, September 18, 2017 3:02 PM >To: Kavanagh, Mark B <mark.b.kavan...@intel.com>; ovs-dev@openvswitch.org >Subject: RE: [ovs-dev] MTU in i40e dpdk driver > >Hi, >It is set to 2140.
That should accommodate a max packet length of 2158 (i.e. MTU + ETHER_HDR (14B) + ETHER_CRC (4B)). Is the VM inside a VLAN by any chance? The presence of a VLAN tag would account for the additional 4B. -Mark > >compute-0-4:~# ovs-vsctl get Interface dpdk1 mtu >2140 > >Regards, >Nitin > >-----Original Message----- >From: Kavanagh, Mark B [mailto:mark.b.kavan...@intel.com] >Sent: Monday, September 18, 2017 7:26 PM >To: Nitin Katiyar <nitin.kati...@ericsson.com>; ovs-dev@openvswitch.org >Subject: Re: [ovs-dev] MTU in i40e dpdk driver > >>From: ovs-dev-boun...@openvswitch.org >>[mailto:ovs-dev-boun...@openvswitch.org] >>On Behalf Of Nitin Katiyar >>Sent: Monday, September 18, 2017 2:05 PM >>To: ovs-dev@openvswitch.org >>Subject: [ovs-dev] MTU in i40e dpdk driver >> >>Hi, >>We are using OVS-DPDK (2.6 version) with Fortville NIC (configured in >>25G >>mode) being used as dpdk port. The setup involves 2 VMs running on 2 >>different computes (destination VM in compute with 10G NIC while >>originating VM is in compute with Fortville NIC). All the interfaces in >>the path are configured with MTU of 2140. >> >>While pinging with size of 2112 (IP packet of 2140 bytes) we found that >>ping response does not reach originating VM (i.e on compute with Fortville >NIC) . >>DPDK interface does not show any drop but we don't see any ping >>response received at DPDK port (verified using port-mirroring). We also >>don't see any rule in ovs dpctl for ping response. If we increase the >>MTU of DPDK interface by 4 bytes or reduce the ping size by 4 bytes then it >works. >> >>The same configuration works between 10G NICs on both sides. >> >>Is it a known issue with i40 dpdk driver? > >Hi Nitin, > >What is the MTU of the DPDK ports in this setup? > > ovs-vscl get Interface <iface_name> mtu > >Thanks, >Mark > >> >>Regards, >>Nitin >>_______________________________________________ >>dev mailing list >>d...@openvswitch.org >>https://mail.openvswitch.org/mailman/listinfo/ovs-dev _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
