[CentOS] Jumbo frames problem with Realtek NICs?

Fri Jun 24 09:52:25 UTC 2011
Christopher Chan <christopher.chan at bradbury.edu.hk>

On Friday, June 24, 2011 05:06 PM, Ljubomir Ljubojevic wrote:
> Christopher Chan wrote:
>> On Friday, June 24, 2011 02:33 PM, Emmanuel Noobadmin wrote:
>>> On 6/24/11, Christopher Chan<christopher.chan at bradbury.edu.hk>   wrote:
>>>> On Friday, June 24, 2011 01:20 AM, Emmanuel Noobadmin wrote:
>>>>> First bottleneck was discovering the max MTU allowed on these is 7K
>>>>> instead of 9K but googling seems to indicate that the RTL8168B is only
>>>>> capable of 4K frames.
>>>> Yeah, the 8168C goes up to 7k. Some 8168B go up to 6k.
>>> In cases like this where there are conflicting sources of information
>>> regarding the max MTU of a NIC, what would be the correct way to
>>> determine the actual max MTU? I figured the 7K limit basically by
>>> doing a binary search with the ifconfig mtu commands. But is the this
>>> figure simply what the driver will accept for the controller it
>>> identified or is that the actual hardware limit?
>>
>> Given that these are the limits from Realtek's own Windows drivers, I'd
>> say they are hardware limits and different from chipset/rev.
>
>
>
> This post:
> http://ubuntuforums.org/showthread.php?t=1628575
> Suggests that Windows and OpenSolaris were pusing 3x more then his
> current Ubuntu. This would suggest Linux driver problem. That is why I
> suggested ElRepo driver.

No way jumbo frames is enabled on OpenSolaris/OpenIndiana. I run 
OpenIndiana here with boards that have realtek onboard. They refuse to 
enable jumbo frame support.