EM(4) - Link flap when bridged and adding members (em bridge flap)

[David P. Discher]

I’m seeing this in -head as well as 10-stable (r274577) on two different sets of hardware. 

When an em interface is a member of a bridge, (if_bridge(4)), the link flaps.  This is reported on the console as well as can be seen with loss of connectivity.  This seems to be easily replicated.  

 ifconfig bridge0 create
 ifconfig bridge addm em0
 ifconfig epair0 create
 ifconfig bridge addm epair0a 
  < link flap >

Two different systems, the behavior is the same.

em0 at pci0:6:0:0:	class=0x020000 card=0x109615d9 chip=0x10968086 rev=0x01 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = '80003ES2LAN Gigabit Ethernet Controller (Copper)'
    class      = network
    subclass   = ethernet


em0 at pci0:1:0:0:	class=0x020000 card=0x10d315d9 chip=0x10d38086 rev=0x00 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = '82574L Gigabit Network Connection'
    class      = network
    subclass   = ethernet

-
David P. Discher
http://davidpdischer.com/
AIM: DavidDPD | Y!M: daviddpdz 



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