16.04.02 + HWE breaks Networking Jumbo Frames for BCM5709

[Van Stokes, Jr.]

Suggested problem type: regression
Sub-system: networking
See also: https://askubuntu.com/questions/913018/ubuntu-16-04-02-hwe-breaks-networking-jumbo-frames-for-bcm5709

I upgraded the server from 14.04 to 16.04. The networking was working fine and supported Jumbo Frames. But after the upgrade I am getting:

SIOCSIFMTU: Invalid argument

when trying to set the frame size.

I have three Dell servers with this problem. I know it has to do with with 16.04 and/or +HWE because I have still have the same model Dell servers running 14.04 and they have Jumbo Frames enabled.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-generic-hwe-16.04 4.8.0.51.22
ProcVersionSignature: Ubuntu 4.8.0-51.54~16.04.1-generic 4.8.17
Uname: Linux 4.8.0-51-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
Date: Tue May 9 07:53:10 2017
InstallationDate: Installed on 2015-09-08 (608 days ago)
InstallationMedia: Ubuntu-Server 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: linux-meta-hwe
UpgradeStatus: Upgraded to xenial on 2017-04-10 (28 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.