[CentOS] centos 6 and super jumbo frames

Mon Nov 9 17:57:32 UTC 2015
Steve Clark <sclark at netwolves.com>

On 11/09/2015 12:36 PM, Gordon Messmer wrote:
> On 11/09/2015 08:34 AM, Steve Clark wrote:
>> Has anyone using CentOS 6 been able to successfully set an mtu larger
>> than 9710
>> on an interface.
> Maximum frame size varies from implementation to implementation:
> http://pages.uoregon.edu/joe/jumbo-clean-gear.html
>
> It's also worth noting that that due to offloading features in modern
> NICs, there's often very little benefit to large frames. Since you
> *really* need all of the devices on any network segment to use the same
> MTU, the best option might be to eliminate jumbo frames (and test the
> impact of doing so in terms of throughput and CPU utilization).
>
Hi Gordon,

Thanks for the response.

The real issue relates to doing pcap on an interface that is
hooked to a span port. The super jumbo frames cause rx_long_length_errors: 2701813
which show up in our monitoring software and the customer thinks there are error on his
network.

So I wanted to increase the mtu on the interface so these errors would not be reported.


-- 
Stephen Clark
*NetWolves Managed Services, LLC.*
Director of Technology
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark at netwolves.com
http://www.netwolves.com