> On 12-Feb-2024, at 8:36 PM, Ihar Hrachyshka <ihrac...@redhat.com> wrote: > > On Tue, Jan 30, 2024 at 10:52 PM Naveen Yerramneni > <naveen.yerramn...@nutanix.com> wrote: > > > > On 29-Jan-2024, at 9:11 PM, Ihar Hrachyshka <ihrac...@redhat.com> wrote: > > > > On Mon, Jan 22, 2024 at 12:22 PM Naveen Yerramneni > > <naveen.yerramn...@nutanix.com> wrote: > > This option can be used to enable/disable arp/nd reply flows. > > > > Usecase: > > ========= > > It is useful to reduce packet loss when VM is being migrated to > > > > It may indeed be useful to be able to disable ARP responder for a LS/port. > > > > I am wondering if you have details about your packet loss issues when > > migrating a VM. Could you please confirm that we are talking about live > > migration (e.g. through libvirt) and that you already use multichassis port > > bindings to host the same port on multiple chassis (on source and > > destination)? In this case, OVN will set up flows that will clone (flood) > > traffic to both locations proactively, for the moment when your hypervisor > > switches running the VM from source to destination. You should not observe > > (significant) packet losses in this scenario. > > VM migration is happening between two different logical switches (i.e., ports > are different) hence requested-chassis option is not helpful here. In this > case, same VLAN is stretched using VXLAN (external VTEP devices). > > Thanks for getting back to me. It's interesting to see how other people deal > with the problem. I now see that you are dealing with VLAN stretched over > VTEPs that are not under control of OVN and hence cannot be educated about > port location. > > If I may ask, in your scenario, how do you retain identity for a VM interface > (MAC, IPs) while swapping LSPs that back the interface? Do you set addresses > for both LSPs to the same MAC/IP tuple?
Yes, MAC, IP are same for both LSPs. > > Packet loss is observed in 2 cases: > 1. When port is configured on the destination but migration is still in > progress. Patch raised for this - > https://www.mail-archive.com/ovs-dev@openvswitch.org/msg82745.html > [mail-archive.com] > 2. When VM sends GARP packet post migration and port is not yet deleted on > the source side then, source side logical switch responds to GARP. This makes > the intermediate VTEP devices to incorrectly learn the location of the port. > Skipping ARP/ND responder and letting the ARP/ND get flooded to learn the > location of the port properly. > > > > different AZ via VXLAN tunnel. Port is configured in both AZs > > on different logical switches which are sharing same IP subnet. > > > > This snippet above suggests to me that you migrate between different > > logical switch ports? Could you please elaborate on how you set up your > > overlay connectivity for the VM? > > > > The reason I ask is because live migration reuses the same LSP, only > > changing the chassis that host(s) the LSP. > > VM migration is happening between two different logical switches (i.e., ports > are different). In this case, same VLAN is stretched using VXLAN (external > VTEP devices). > > > > > In reality, the port is active on only one logical switch. > > Skipping ARP/ND responder and letting the ARP/ND get flooded to > > learn the location of the port. > > > > Signed-off-by: Naveen Yerramneni <naveen.yerramn...@nutanix.com> > > --- > > northd/northd.c | 10 +++++++++- > > tests/ovn-northd.at [ovn-northd.at] [ovn-northd.at [ovn-northd.at]] | 31 > > +++++++++++++++++++++++++++++++ > > 2 files changed, 40 insertions(+), 1 deletion(-) > > > > diff --git a/northd/northd.c b/northd/northd.c > > index 952f8200d..4e070c0fe 100644 > > --- a/northd/northd.c > > +++ b/northd/northd.c > > @@ -1844,6 +1844,12 @@ localnet_can_learn_mac(const struct > > nbrec_logical_switch_port *nbsp) > > return smap_get_bool( ->options, "localnet_learn_fdb", false); > > } > > > > +static bool > > +lsp_disable_arp_nd_rsp(const struct nbrec_logical_switch_port *nbsp) > > +{ > > + return smap_get_bool( ->options, "disable_arp_nd_rsp", false); > > +} > > + > > static bool > > lsp_is_type_changed(const struct sbrec_port_binding *sb, > > const struct nbrec_logical_switch_port *nbsp, > > @@ -9921,7 +9927,9 @@ build_lswitch_arp_nd_responder_known_ips(struct > > ovn_port *op, > > return; > > } > > > > - if (lsp_is_external(op->nbsp) || op->has_unknown) { > > + if (lsp_is_external(op->nbsp) || op->has_unknown || > > + (!strcmp(op->nbsp->type, "") && > > + lsp_disable_arp_nd_rsp(op->nbsp))) { > > return; > > } > > > > diff --git a/tests/ovn-northd.at [ovn-northd.at] [ovn-northd.at > > [ovn-northd.at]] b/tests/ovn-northd.at [ovn-northd.at] [ovn-northd.at > > [ovn-northd.at]] > > index 9a0d418e4..9a36ee810 100644 > > --- a/tests/ovn-northd.at [ovn-northd.at] [ovn-northd.at [ovn-northd.at]] > > +++ b/tests/ovn-northd.at [ovn-northd.at] [ovn-northd.at [ovn-northd.at]] > > @@ -11094,5 +11094,36 @@ AT_CHECK([ovn-sbctl dump-flows S1 | grep pre_acl | > > sed 's/table=./table=?/'], [0 > > ]) > > > > > > +AT_CLEANUP > > +]) > > + > > +OVN_FOR_EACH_NORTHD_NO_HV([ > > +AT_SETUP([check options:disable_arp_nd_rsp for LSP]) > > +ovn_start NORTHD_TYPE > > +ovn-nbctl ls-add S1 > > +ovn-nbctl --wait=sb lsp-add S1 S1-vm1 > > +ovn-nbctl --wait=sb lsp-set-addresses S1-vm1 "50:54:00:00:00:010 > > 192.168.0.10 fd00::10" > > + > > +ovn-sbctl dump-flows S1 > S1flows > > +AT_CAPTURE_FILE([S1flows]) > > + > > +AT_CHECK([grep -e "ls_in_arp_rsp" S1flows | sed 's/table=../table=??/'], > > [0], [dnl > > + table=??(ls_in_arp_rsp ), priority=100 , match=(arp.tpa == > > 192.168.0.10 && arp.op == 1 && inport == "S1-vm1"), action=(next;) > > + table=??(ls_in_arp_rsp ), priority=100 , match=(nd_ns && ip6.dst > > == {fd00::10, ff02::1:ff00:10} && nd.target == fd00::10 && inport == > > "S1-vm1"), action=(next;) > > + table=??(ls_in_arp_rsp ), priority=50 , match=(arp.tpa == > > 192.168.0.10 && arp.op == 1), action=(eth.dst = eth.src; eth.src = > > 50:54:00:00:00:10; arp.op = 2; /* ARP reply */ arp.tha = arp.sha; arp.sha = > > 50:54:00:00:00:10; arp.tpa = arp.spa; arp.spa = 192.168.0.10; outport = > > inport; flags.loopback = 1; output;) > > + table=??(ls_in_arp_rsp ), priority=50 , match=(nd_ns && ip6.dst > > == {fd00::10, ff02::1:ff00:10} && nd.target == fd00::10), action=(nd_na { > > eth.src = 50:54:00:00:00:10; ip6.src = fd00::10; nd.target = fd00::10; > > nd.tll = 50:54:00:00:00:10; outport = inport; flags.loopback = 1; output; > > };) > > + table=??(ls_in_arp_rsp ), priority=0 , match=(1), action=(next;) > > +]) > > + > > +#Set the disable_arp_nd_rsp option and verify the flow > > +ovn-nbctl --wait=sb set logical_switch_port S1-vm1 > > options:disable_arp_nd_rsp=true > > + > > +ovn-sbctl dump-flows S1 > S1flows > > +AT_CAPTURE_FILE([S1flows]) > > + > > +AT_CHECK([grep -e "ls_in_arp_rsp" S1flows | sed 's/table=../table=??/'], > > [0], [dnl > > + table=??(ls_in_arp_rsp ), priority=0 , match=(1), action=(next;) > > +]) > > + > > AT_CLEANUP > > ]) > > -- > > 2.36.6 > > > > _______________________________________________ > > dev mailing list > > d...@openvswitch.org > > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > > [mail.openvswitch.org] [mail.openvswitch.org [mail.openvswitch.org]] _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
