Handling Jumbo Packets

[Luigi Rizzo]

On Mon, Mar 24, 2014 at 10:47 AM, soumya panigrahi <
soumyapanigrahi at gmail.com> wrote:

>
> On Mon, Mar 24, 2014 at 2:45 PM, Luigi Rizzo <rizzo at iet.unipi.it> wrote:
>
>>
>>
>>
>> On Mon, Mar 24, 2014 at 7:40 AM, soumya panigrahi <
>> soumyapanigrahi at gmail.com> wrote:
>>
>>> Hi,
>>>
>>> First of all I would like to thank you all for developing an awesome
>>> packet capturing framework.
>>> I have been using it recently and find it very very fast and efficient.
>>>
>>> However off late I am trying to capture Jumbo packets on the network for
>>> the following scenario's but that doesn't seem to be working.
>>>
>>
>> the sysctl tree dev.netmap (on FreeBSD)
>> or the filesystem
>> /sys/module/netmap_lin/parameters
>> (on Linux)
>> have a number of parameters that control buffer numbers and sizes.
>> In particular "buf_size" is used to allocate packet buffers and
>> you can bump it up from 2048 to something larger to accommodate
>> jumbo buffers.
>>
>> Depending on the NIC you may need to do something in the initialization
>> of the NIC itself to allow sending/receiving frames larger than 1518
>> bytes,
>> but I'd just try and see whether it works for you now.
>>
>> cheers
>> luigi
>>
>
> Thanks a lot for the quick response.
> I will also try to see if we can handle Jumbo frames by tweaking the
> buf_size parameter on Linux.
> In addition can you advice if NetMap can de-fragment Jumbo packets that
> were fragmented as IP packets by intermediate IP device because of MTU size
> limitation?
>

no, netmap does not do fragmentation or reassembly

cheers
luigi
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