tg3 - card generated broken arp queries ?

tg3 - card generated broken arp queries ?

[Florian Lohoff]

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Hi,
we are debugging networking problems and stumpled over interesting arp
queries from one of our machines. Its currently an 2.6.5 vanilla.
Ethernet card is an tg3.

0000:02:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5704 Gigabit Ethernet (rev 02)
        Subsystem: Unknown device 1734:100b
        Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+ Stepping- SERR+ FastB2B-
        Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Latency: 64 (16000ns min), Cache Line Size: 0x10 (64 bytes)
        Interrupt: pin A routed to IRQ 18
        Region 0: Memory at fa110000 (64-bit, non-prefetchable)
        Region 2: Memory at fa100000 (64-bit, non-prefetchable) [size=64K]
        Capabilities: [40]      Capabilities: [48] Power Management version 2
                Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot+,D3cold+)
                Status: D0 PME-Enable+ DSel=0 DScale=1 PME-
        Capabilities: [50] Vital Product Data
        Capabilities: [58] Message Signalled Interrupts: 64bit+ Queue=0/3 Enable-
                Address: 0000000100000000  Data: a02d

I changed the mac address with "ifconfig eth0 hw ether de:ad:be:ef:00:00"
and watched the ethernet with a port mirror.  Original mac address of
the interface is: 0:30:5:46:b1:9e

The broken arps were still coming with the original mac address:

tcpdump -s 1600 -vvv -n -e -i eth0 arp
09:48:03.168087 0:30:5:46:b1:9e ff:ff:ff:ff:ff:ff 0806 60: arp who-has 0.0.0.0 tell 0.0.0.0

On the machine itself i couldnt see those arp queries in the tcpdump -
It seems the card itself generates those arp queries.

Is this possible at all ? Is it a known bug ? 

Flo
-- 
Florian Lohoff                  flo@rfc822.org             +49-171-2280134
                        Heisenberg may have been here.

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