[Bug 229432] 11.2 network em driver - connection link flaps

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=229432

            Bug ID: 229432
           Summary: 11.2 network em driver - connection link flaps
           Product: Base System
           Version: 11.2-RELEASE
          Hardware: i386
                OS: Any
            Status: New
          Severity: Affects Many People
          Priority: ---
         Component: kern
          Assignee: bugs at FreeBSD.org
          Reporter: deaven at deaven.net

Created attachment 194795
  --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=194795&action=edit
dmesg output for (working) 11.1 system

Seemingly uneventful upgrade from 11.1-RELEASE-p11 to 11.2-RELEASE-p0, resulted
in constant link state changes running the new kernel:

Jun 30 11:00:06 hellcat kernel: em1: link state changed to DOWN
Jun 30 11:00:06 hellcat dhclient: New IP Address (em1): 24.211.23.77
Jun 30 11:00:06 hellcat dhclient: New Subnet Mask (em1): 255.255.240.0
Jun 30 11:00:06 hellcat dhclient: New Broadcast Address (em1): 255.255.255.255
Jun 30 11:00:06 hellcat dhclient: New Routers (em1): 24.211.16.1
Jun 30 11:00:10 hellcat kernel: em1: link state changed to UP
Jun 30 11:00:10 hellcat kernel: em1: link state changed to DOWN
Jun 30 11:00:10 hellcat dhclient: New IP Address (em1): 24.211.23.77
Jun 30 11:00:10 hellcat dhclient: New Subnet Mask (em1): 255.255.240.0
Jun 30 11:00:10 hellcat dhclient: New Broadcast Address (em1): 255.255.255.255
Jun 30 11:00:10 hellcat dhclient: New Routers (em1): 24.211.16.1
Jun 30 11:00:14 hellcat kernel: em1: link state changed to UP
Jun 30 11:00:14 hellcat kernel: em1: link state changed to DOWN

The connection is the WAN side of a FreeBSD router, connected to a Motorola
SURFboard SB6141 DOCSIS 3.0 Cable Modem. During this activity, ISP connection
up/down links are stable, only ethernet link is changing. It stays up for few
hundred milliseconds, enough to route some traffic but obviously frequent
dropouts.

New ethernet cable, various warm and cold reboots of modem and FreeBSD box,
turning off pf service all made no difference.  Also confirmed running correct
11.2 config using "freebsd-update IDS".

Rolling back to 11.1, immediately works again.  This system has historically
experienced link changes (which I assumed were associated with ISP issues)
about once per 3 months, link goes down and comes back up within a minute. 

Here's the em part of kernel message during 11.1 boot:
em1: <Intel(R) PRO/1000 Network Connection 7.6.1-k> port 0x1000-0x101f mem
0x80020000-0x8003ffff,0x80000000-0x8001ffff,0x80040000-0x80043fff irq 17 at
device 0.0 on pci2
em1: Using MSIX interrupts with 3 vectors
em1: Ethernet address: 00:22:4d:ac:a6:f0

I've attached the full dmesg output as well.

-- 
You are receiving this mail because:
You are the assignee for the bug.