MX84 Packet Loss

Building a reputation

MX84 Packet Loss

Just upgraded our MX84 to 15.33 and still we see this known bug (has been a long time):


  • After making some configuration changes on MX84 appliances, a brief period of packet loss may occur. This will affect all MX84 appliances on all MX firmware versions


I'm not convinced it's just for a brief period. While we normally experience a little with BT fibre, after the upgrade the internet was nearly unusable this morning at around 6:30.





I: this is when the upgrade occurred

II: I had to change the config on the WAN port from Auto to 100 Duplex and then back again



Has anyone else experience this? Never had these problems with the MX64 at the same site (we recently moved the MX84 from a DC to our office).


Kind of a big deal

That is not the bug.


The bug only occurs when doing a config change, which causes the LAN Ethernet ports to transition briefly into a non-forwarding state and back again.  It only does this once per config change.  This can be particularly nasty when people dual connect MX84's because it can cause short term spanning-tree loops.


It does not cause ongoing WAN packet loss.



You look like you have experienced a simple issue if the speed/duplex (probably the duplex) not being correctly auto-negotiated.  If it only happens once I wouldn't do anything.  If it happens again replace the cable.

This issue with packet loss when making config changes, will they ever fix that? We recently moved our phone system to an external datacentre and now whenever we make a config change the phones loose connection due to the packet loss and reboot. Which isn’t ideal!


The packet loss issue has been around for some time it seems, but will it ever be fixed?

Kind of a big deal

Because it hasn't been resolved after all of this time - I suspect it is related to a non-fixable hardware issue.

Get notified when there are additional replies to this discussion.
Welcome to the Meraki Community!
To start contributing, simply sign in with your Cisco account. If you don't yet have a Cisco account, you can sign up.