Dell D800 (FBSD 5.2-release) Broadcom BCM5705M MTU/Jumbo Problem

[Andre Oppermann]

Mike Hunter wrote:
> 
> Hi everybody,
> 
> I'm going to be trying to get gigabit throughput between my laptop (Dell
> Latitude D800 running 5.2-release) and a shuttle box running FreeBSD 5.1
> (not in front of me at the moment.)  As part of the process, I attempted
> to increase the frame size on my laptop, only to be greeted with
> disappointment:
> 
> celeste# ifconfig bge0
> bge0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500
>         options=1b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING>
>         ether 00:0b:db:99:d6:06
>         media: Ethernet 1000baseTX <full-duplex> (none)
>         status: no carrier
> celeste# ifconfig bge0 mtu 9000
> ifconfig: ioctl (set mtu): Invalid argument
> celeste# ifconfig bge0 mtu 1501
> ifconfig: ioctl (set mtu): Invalid argument
> celeste# ifconfig bge0 mtu 1500
> celeste#
> 
> The C file talks about being able to do jumbo frames when the mtu is big
> enough...anybody know what I'm missing?  My card is a "Broadcom BCM5705M"
> and I'm running FreeBSD 5.2-release.  When I asked google, it mostly
> pointed me at comments in if_bge.c talking about jumbo frames :|

Hmm... works for me (on my shiny new dual-Opteron):

# ifconfig bge1 mtu 2000
# ifconfig bge1
bge1: flags=8842<BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 2000
        options=1b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING>
        ether 00:e0:81:27:e0:aa
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active

Mine is a 5704C dual GigE chip.

-- 
Andre