OVS

General

• Ensure the bridge was created with datapath_type=netdev
• Ensure ovs-vswitchd actually starts up, problems in DPDK setup typically cause it to fail to start up. With journald, you can use journalctl -t ovs-vswitchd to see the DPDK messages, or grep for ovs-vswitchd from system log files if using rsyslog or similar.

Virtual NICs

• Ensure its NOT bound to uio_pci_generic
• Ensure unique MAC addresses on each device

Port info and statistics

• Information about port speeds and other state can be viewed with ovs-ofctl show <bridge, for example:

  # ovs-ofctl show br0
  OFPT_FEATURES_REPLY (xid=0x2): dpid:0000ecf4bbdc0380
  n_tables:254, n_buffers:256
  capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS ARP_MATCH_IP
  actions: output enqueue set_vlan_vid set_vlan_pcp strip_vlan mod_dl_src mod_dl_dst mod_nw_src mod_nw_dst mod_nw_tos mod_tp_src mod_tp_dst
   1(dpdk0): addr:ec:f4:bb:dc:03:80
       config:     0
       state:      0
       current:    10GB-FD
       supported:  1GB-HD AUTO_NEG
       speed: 10000 Mbps now, 1000 Mbps max
   2(dpdk1): addr:ec:f4:bb:dc:03:82
       config:     0
       state:      0
       current:    10GB-FD
       supported:  1GB-HD AUTO_NEG
       speed: 10000 Mbps now, 1000 Mbps max
   LOCAL(br0): addr:ec:f4:bb:dc:03:80
       config:     PORT_DOWN
       state:      LINK_DOWN
       current:    10MB-FD COPPER
       speed: 10 Mbps now, 0 Mbps max
  OFPT_GET_CONFIG_REPLY (xid=0x4): frags=normal miss_send_len=0
  

• OVS port statistics, including transmitted and received packets, error counts etc can be viewed with ovs-ofctl dump-ports <bridge>, for example:

  # ovs-ofctl dump-ports br0
  OFPST_PORT reply (xid=0x2): 3 ports
  port LOCAL: rx pkts=0, bytes=0, drop=0, errs=0, frame=0, over=0, crc=0
           tx pkts=6016480, bytes=385054720, drop=6016480, errs=0, coll=0
  port  1: rx pkts=204126460, bytes=13880599280, drop=0, errs=0, frame=?, over=?, crc=0
           tx pkts=204125884, bytes=13880557936, drop=0, errs=0, coll=?
  port  2: rx pkts=204125756, bytes=13880551408, drop=0, errs=0, frame=?, over=?, crc=0
           tx pkts=204126460, bytes=13880597104, drop=0, errs=0, coll=?
  

• PMD statistics (primarily useful for performance tuning) can be viewed with ovs-appctl dpif-netdev/pmd-stats-show command. For example:

  # ovs-appctl dpif-netdev/pmd-stats-show
  main thread:
          emc hits:0
          megaflow hits:0
          miss:0
          lost:0
          polling cycles:73897097 (100.00%)
          processing cycles:0 (0.00%)
  pmd thread numa_id 0 core_id 0:
          emc hits:69249886
          megaflow hits:32
          miss:2
          lost:0
          polling cycles:6539496906301 (98.69%)
          processing cycles:86741963460 (1.31%)
          avg cycles per packet: 95685.87 (6626238869761/69249920)
          avg processing cycles per packet: 1252.59 (86741963460/69249920)
  

• See man 8 ovs-vswitchd for numerous other datapath and interface debugging commands.