Subject: Re: 4.16 issue with mbim modem and ping with size > 14552 bytes

From: Greg KH <[email-masked]>
Date: Thu, 24 May 2018 17:53:34 +0200

On Thu, May 24, 2018 at 05:04:49PM +0200, Daniele Palmas wrote:
> Hello,
> 
> I have an issue with an USB mbim modem when trying to send with ping
> more than 14552 bytes: it looks like to me a kernel issue, but not at
> the cdc_mbim or cdc_ncm level, anyway not sure, so I'm reporting the
> issue.
> 
> My kernel is 4.16. The device is the following:

Does older kernels work, or is this something that has always been
there?

I ask, as my mobile provider does horrible things to large packet sizes.
So much so that I have to set the mtu to 1280 just to get things to work
properly when tethering my phone through to my laptop.  So this might be
a network provider issue :)

thanks,

greg k-h