windows PCs/Dell with both wired ethernet and wifi active getting disconnected from Meraki switch

[hmc250000]

We have come across some issues where windows clients (Dell laptops), that have both ethernet and wifi connected, are getting disconnected randomly from a Meraki switch every so often. The port on the switch goes into a disconnected state and the only way to get traffic to pass through the port again was to cycle the port.  I know we can set the priority on each interface on the PC however we had no issues with this before. 

When one interface is active and the other passive, it does not seem to cause problems.

Has anybody dealt with this before? 

[AlexL1]

Hi hmc250000,

I hope your day is going well.

Please, provide more detail information:

PART 1:

• When did the issue start happening?
• Did you perform any network or configuration changes around that time?
• What's the switchport configuration?
• Are all client devices that having issue with the same model, OS, etc.?
• Are there any recent Windows updates?
• Have you tested updating the Windows OS, drivers etc. to the latest?
• When PCs connected via Wired - when exactly disconnected - when it goes to standby / sleep mode etc.?
• Do you see any Event logs for the specific devices?
• Have you taken packet captures? Does the  PC still have IP address?
• When you configure the PC with a Static IP address - does it experience the issue?
• Ensure the Meraki switch is running the latest firmware

PART 2:

There are two issue - via wired and wireless connectivity - therefore, they should be troubleshoot separately. Let's start with Wired connectivity:

1. When the PC disconnects:
   • What's the physical switchport LED status light?
   • Is the PC directly connected to the Switchport OR via Patch panel? Is the issue happening when directly connected to the switchport?
   • Is the PC ONLY connect via Wired connection at that time?
   • Any error messages or icon changes on the PC itself?
   • Have you performed cable test?
     
     
     
2. Can the PC perform the following:
   • Ping it's Gateway
   • Ping 8.8.8.8
   • Tracert 8.8.8.8
   • Is it using Public DNS Server?

If you have any questions, please don't hesitate to contact us.

[hmc250000]

Please, provide more detail information:
When did the issue start happening?
Sometime in April or early May

Did you perform any network or configuration changes around that time?
No

What's the switchport configuration?
Default settings:
Port status Enabled
Type  Trunk
Native VLAN 1
Allowed VLANs     all
Access policy     Open
Link negotiation  Auto negotiate (1 Gbps)
RSTP  Enabled (Forwarding)
Port schedule     Unscheduled
Port isolation    Disabled
Trusted DAI Disabled
UDLD  Alert only
Tags  none
PoE   Enabled
Port mirroring    Not mirroring traffic

Are all client devices that having issue with the same model, OS, etc.?
No, not all. We mostly use Dell Latittude laptops but have Dell desktops as well.

Are there any recent Windows updates?
No.

Have you tested updating the Windows OS, drivers etc. to the latest?
Manually disconnecting wireless on the machines that have both wired and wireless connected seems to resolve the issue. This goes for desktops as well.

When PCs connected via Wired - when exactly disconnected - when it goes to standby / sleep mode etc.?
This is intermittent. We can't think of anything else than the PC is sending traffic on both the wired and wireless interfaces. THe PC is not going in sleep mode. THe user is actively working on the computer and gets disconnected.

Do you see any Event logs for the specific devices?
Nothing out of the ordinary.

Have you taken packet captures? Does the PC still have IP address?
No, because it's intermittent and we can't reproduce it at will.

When you configure the PC with a Static IP address - does it experience the issue?
I haven't thought of that. The PC's obtain DHCP addresses.

Ensure the Meraki switch is running the latest firmware
Yes, neither the old nor the new firmware resolved the issue.

[cmr]

@hmc250000 your PCs should be connected to access ports, not trunk ports.  Though that doesn't explain why it has changed recently...  Is the SSID on VLAN 1 as well?

[hmc250000]

Ideally endpoints should connect to access ports but that should not be causing this issue. By default the switches come with trunked ports enabled. 

Yes, wireless SSID is on vlan 1. Which is also not ideal but should not be causing problems.

Again this was working fine the way it is. 

[cmr]

There have been a number of Meraki back end changes recently where things that weren't right, but were working seemed to stop.  Ports running at a reduced speed for example.  I had a camera that stopped working with one cable that had been fine for over a year, new cable and its working again, old cable connects a laptop at 1Gb without issues etc.  I'd try them as access ports and see if it makes a difference.

[PhilipDAth]

I am not familiar with Dell, but I have seen this with HP notebooks.  They have an option in their BIOS to disable one network Interface if another is up (to guarantee that a machine only has one physical link to the network at a time).

Another possibility is that it is EEE (energy-efficient Ethernet).  It might be powering down to save power.  Try disabling power saving on the NIC.

[Tim_De_Groef]

We had a similar issue at one of our sites. There, it was a mix of Dell Latitudes and HP desktops.

The HP desktops had no problems, but the Dell Latitudes (new devices) were experiencing constant issues.

The problem is still not 100% under control, but removing the 'Dell Optimizer' software already brought some improvement.
That software combines wireless and wired connections under certain circumstances and doesn't always function correctly.

[cmr]

@Tim_De_Groef I think you have it there, I was wondering why I hadn't seen it on sites with many Dell laptops, but we always remove that optimiser software!