Rapid link state changes on bge(4) interface

[Slawek Zak]

Hi,

I'm testing network failover on IBM BladeCenter running FreeBSD 6.1
STABLE for Sep 6th.

I suspect a problem with link state change detection in bge code. When
I disable internal port on chassis built-in ethernet switch, kernel
floods syslog with messages about link state changes and coalescing
them. Log snippet follows:

Sep 13 14:58:28 w3-6 kernel: bge1: link state changed to DOWN
Sep 13 14:58:28 w3-6 kernel: bge1: link state changed to UP
Sep 13 14:58:29 w3-6 kernel: bge1: link state changed to DOWN
Sep 13 14:58:29 w3-6 kernel: bge1: link state changed to UP
Sep 13 14:58:29 w3-6 kernel: bge1: link state changed to DOWN
Sep 13 14:58:29 w3-6 kernel: bge1: 4 link states coalesced
Sep 13 14:58:29 w3-6 kernel: bge1: link state changed to DOWN
Sep 13 14:58:29 w3-6 kernel: bge1: 11 link states coalesced
Sep 13 14:58:29 w3-6 kernel: bge1: link state changed to UP
Sep 13 14:58:30 w3-6 kernel: bge1: link state changed to DOWN
Sep 13 14:58:30 w3-6 kernel: bge1: 3 link states coalesced
Sep 13 14:58:30 w3-6 kernel: bge1: link state changed to UP
Sep 13 14:58:30 w3-6 kernel: bge1: 7 link states coalesced
Sep 13 14:58:30 w3-6 kernel: bge1: link state changed to DOWN
Sep 13 14:58:30 w3-6 kernel: bge1: 4 link states coalesced
Sep 13 14:58:30 w3-6 kernel: bge1: link state changed to DOWN
Sep 13 14:58:30 w3-6 kernel: bge1: 2 link states coalesced

As you can see, messages are generated in rapid succession and
therefore any probing of link state change by ng_one2many for
interface failover is meaningless. Ethernet switch doesn't register
and log any interface state changes after disabling this port. LS20
blades use chipset 8850. My firmware is 3.38, full changelog, if it is
of any help, is here:

http://www-307.ibm.com/pc/support/site.wss/license.do?filename=pc_servers/brcm_fw_nic_12021_anyos_anycpu.chg

Any ideas what might be wrong?

/S
-- 
Sławek Żak / UNIX Systems Administrator