"ovs datapath_type netdev" should only be used for VM, neutron router related virtual network devices are not compatible with it, [1] has those limitations. The only way you can run L3 routers with VMs (using DPDK) is to run l3-agents and ovs-agents in dedicated nodes with data patch type system, while VMs in hosts with netdev.
[1] https://docs.openstack.org/neutron/latest/admin/config-ovs-dpdk.html #known-limitations ** Changed in: neutron Status: New => Won't Fix -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to neutron. https://bugs.launchpad.net/bugs/1931844 Title: Can't ping router with packet size greater than 1476 when ovs datapath_type set to netdev Status in neutron: Won't Fix Bug description: Setup: Openstack origin/stable/wallaby deployed by devstack on single node [stack@localhost devstack]$ cat /etc/centos-release CentOS Linux release 8.4.2105 [stack@localhost devstack]$ uname -a Linux localhost.localdomain 4.18.0-305.3.1.el8.x86_64 #1 SMP Tue Jun 1 16:14:33 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux [stack@localhost devstack]$ [stack@localhost devstack]$ git status HEAD detached at origin/stable/wallaby ovs version (builded with DPDK) [stack@localhost devstack]$ ovs-vswitchd --version ovs-vswitchd (Open vSwitch) 2.13.4 DPDK 19.11.7 [stack@localhost devstack]$ cat /etc/neutron/plugins/ml2/ml2_conf.ini |grep datapath_type datapath_type = netdev [stack@localhost devstack]$ cat /etc/neutron/plugins/ml2/ml2_conf.ini |grep mtu path_mtu = 9000 physical_network_mtus = 9000 [stack@localhost devstack]$ cat /etc/neutron/neutron.conf |grep mtu global_physnet_mtu = 9000 Steps: 1. Setup hugepages, update flavor (hw:mem_page_size='large', hw_rng:allowed='True') 2. boot vm and try ping router and vice versa br-int: Bridge br-int Controller "tcp:127.0.0.1:6633" is_connected: true fail_mode: secure datapath_type: netdev Port patch-tun Interface patch-tun type: patch options: {peer=patch-int} Port br-int Interface br-int type: internal Port vhua5beaaae-c8 tag: 1 Interface vhua5beaaae-c8 type: dpdkvhostuserclient options: {vhost-server-path="/var/run/openvswitch/vhua5beaaae-c8"} Port qr-c48b27ee-0f tag: 1 Interface qr-c48b27ee-0f type: internal Port int-br-ex Interface int-br-ex type: patch options: {peer=phy-br-ex} Port tap3b960ab3-6a tag: 1 Interface tap3b960ab3-6a type: internal From VM: [root@test-mtu ~]# ip a |grep mtu 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 8950 qdisc fq_codel state UP group default qlen 1000 [root@test-mtu ~]# [root@test-mtu ~]# ping 192.168.1.1 PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data. 64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=0.275 ms 64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=0.167 ms --- 192.168.1.1 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1035ms rtt min/avg/max/mdev = 0.167/0.221/0.275/0.054 ms [root@test-mtu ~]# ping 192.168.1.1 -s 2000 PING 192.168.1.1 (192.168.1.1) 2000(2028) bytes of data. --- 192.168.1.1 ping statistics --- 4 packets transmitted, 0 received, 100% packet loss, time 3086ms [root@test-mtu ~]# ping 192.168.1.1 -c 5 PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data. 64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=0.139 ms 64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=0.154 ms 64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=0.144 ms 64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=0.153 ms 64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=0.146 ms --- 192.168.1.1 ping statistics --- 5 packets transmitted, 5 received, 0% packet loss, time 4005ms rtt min/avg/max/mdev = 0.139/0.147/0.154/0.005 ms [root@test-mtu ~]# ping 192.168.1.1 -c 5 -s 2000 PING 192.168.1.1 (192.168.1.1) 2000(2028) bytes of data. --- 192.168.1.1 ping statistics --- 5 packets transmitted, 0 received, 100% packet loss, time 4084ms [root@test-mtu ~]# In ns: [root@localhost ~]# ip a |grep mtu 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 29: qr-c48b27ee-0f: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 8950 qdisc fq_codel state UNKNOWN group default qlen 1000 [root@localhost ~]# # default packet size: 10:44:41.276140 IP 192.168.1.176 > localhost.localdomain: ICMP echo request, id 7, seq 1, length 64 10:44:41.276176 IP localhost.localdomain > 192.168.1.176: ICMP echo reply, id 7, seq 1, length 64 10:44:42.323564 IP 192.168.1.176 > localhost.localdomain: ICMP echo request, id 7, seq 2, length 64 10:44:42.323594 IP localhost.localdomain > 192.168.1.176: ICMP echo reply, id 7, seq 2, length 64 10:44:43.325048 IP 192.168.1.176 > localhost.localdomain: ICMP echo request, id 7, seq 3, length 64 10:44:43.325075 IP localhost.localdomain > 192.168.1.176: ICMP echo reply, id 7, seq 3, length 64 10:44:44.326474 IP 192.168.1.176 > localhost.localdomain: ICMP echo request, id 7, seq 4, length 64 10:44:44.326501 IP localhost.localdomain > 192.168.1.176: ICMP echo reply, id 7, seq 4, length 64 10:44:45.327838 IP 192.168.1.176 > localhost.localdomain: ICMP echo request, id 7, seq 5, length 64 10:44:45.327865 IP localhost.localdomain > 192.168.1.176: ICMP echo reply, id 7, seq 5, length 64 # packet size 2000 [root@localhost ~]# tcpdump -i qr-c48b27ee-0f icmp dropped privs to tcpdump tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on qr-c48b27ee-0f, link-type EN10MB (Ethernet), capture size 262144 bytes 10:46:00.934011 IP 192.168.1.176 > localhost.localdomain: ICMP echo request, id 9, seq 1, length 2008 10:46:00.934046 IP localhost.localdomain > 192.168.1.176: ICMP echo reply, id 9, seq 1, length 2008 10:46:01.941013 IP 192.168.1.176 > localhost.localdomain: ICMP echo request, id 9, seq 2, length 2008 10:46:01.941051 IP localhost.localdomain > 192.168.1.176: ICMP echo reply, id 9, seq 2, length 2008 10:46:02.965045 IP 192.168.1.176 > localhost.localdomain: ICMP echo request, id 9, seq 3, length 2008 10:46:02.965072 IP localhost.localdomain > 192.168.1.176: ICMP echo reply, id 9, seq 3, length 2008 10:46:03.989043 IP 192.168.1.176 > localhost.localdomain: ICMP echo request, id 9, seq 4, length 2008 10:46:03.989083 IP localhost.localdomain > 192.168.1.176: ICMP echo reply, id 9, seq 4, length 2008 10:46:05.013079 IP 192.168.1.176 > localhost.localdomain: ICMP echo request, id 9, seq 5, length 2008 10:46:05.013108 IP localhost.localdomain > 192.168.1.176: ICMP echo reply, id 9, seq 5, length 2008 From ns: [root@localhost ~]# ping 192.168.1.176 -c 2 PING 192.168.1.176 (192.168.1.176) 56(84) bytes of data. 64 bytes from 192.168.1.176: icmp_seq=1 ttl=64 time=0.193 ms 64 bytes from 192.168.1.176: icmp_seq=2 ttl=64 time=0.163 ms --- 192.168.1.176 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1038ms rtt min/avg/max/mdev = 0.163/0.178/0.193/0.015 ms [root@localhost ~]# ping 192.168.1.176 -c 2 -s 2000 PING 192.168.1.176 (192.168.1.176) 2000(2028) bytes of data. --- 192.168.1.176 ping statistics --- 2 packets transmitted, 0 received, 100% packet loss, time 1060ms [root@localhost ~]# in vm: 08:51:37.228218 IP truncated-ip - 524 bytes missing! host-192-168-1-1.openstacklocal > host-192-168-1-176.openstacklocal: ICMP echo request, id 27328, seq 1, length 2008 08:51:38.245796 IP truncated-ip - 524 bytes missing! host-192-168-1-1.openstacklocal > host-192-168-1-176.openstacklocal: ICMP echo request, id 27328, seq 2, length 2008 The same issue if I try to ping dhcp server If I set ovs datapath_type=system and don't use dpdkvhostuserclient - all works fine To manage notifications about this bug go to: https://bugs.launchpad.net/neutron/+bug/1931844/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : yahoo-eng-team@lists.launchpad.net Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
