At boot, LACP bond in RHEL 6 does not send LACPDUs and bond reports slave speed & duplex as Unknown

Issue

• When the system boots a mode 4 LACP bond does not work. Packet capture and switch status show the host is not sending the expected LACPDUs.

• The /proc/net/bonding/bond0 status file shows the Speed and Duplex of one or more slaves as Unknown.

  $ cat /proc/net/bonding/bond0 
  Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)
  
  Bonding Mode: IEEE 802.3ad Dynamic link aggregation
  Transmit Hash Policy: layer2 (0)
  MII Status: up
  MII Polling Interval (ms): 100
  Up Delay (ms): 0
  Down Delay (ms): 0
  
  802.3ad info
  LACP rate: fast
  Min links: 0
  Aggregator selection policy (ad_select): stable
  Active Aggregator Info:
      Aggregator ID: 1
      Number of ports: 1
      Actor Key: 0
      Partner Key: 1
      Partner Mac Address: 00:00:00:00:00:00
  
  Slave Interface: eth0
  MII Status: up
  Speed: Unknown
  Duplex: Unknown
  Link Failure Count: 0
  Permanent HW addr: 00:11:22:00:00:01
  Aggregator ID: 1
  Slave queue ID: 0
  
  Slave Interface: eth1
  MII Status: up
  Speed: Unknown
  Duplex: Unknown
  Link Failure Count: 0
  Permanent HW addr: 00:11:22:00:00:02
  Aggregator ID: 2
  Slave queue ID: 0