MX84 Port is disconnected when trying to patch another switch

[SimonT]

I am trying to patch a MX84 to another cisco switch and using a copper connection on one of the standard ports. The port is set to a Access port but wont come up in the interface. Patching a laptop to the same cisco switch port comes up right away. Is there any tracing that can be done on the MX84 to see why the port is not coming up

[MerakiDave · Accepted solution]

Hi @SimonT so it sounds like there's no issue with the Cisco switch port if you plugged in a laptop to the same port and it came up right away.  And if the MX84 is online in Dashboard I assume, if you go to the Addressing & VLANs page, if you enable VLANs and scroll down to the per-port VLAN settings and click into that port, the port is enabled?  Make sure it's not a speed mismatch in case something is locked on one side.

Also, try connecting a laptop to the same LAN port on the MX84 - does it come up and you get a link?  If not, try other ports and see if you can get an active link, and point a browser to my.meraki.com and go into the local status page.  On that LSP, you can go into the config page and check the enabled/disabled status and speed/duplex settings.

[SimonT]

Thanks Dave for the idea's I was thinking it might be a port speed setting after reading a few more forum post. I will keep reading and then try your recommendations. 

[MerakiDave]

Sounds good, let me know how it goes.  Also, I was thinking of the MX64 before when you can connect to a LAN interface to get to the local status page, note the MX84 has a dedicated management port where you should be able to plug in a laptop and get to the LSP.  If you haven't done there before, here's the relevant support doc https://documentation.meraki.com/zGeneral_Administration/Tools_and_Troubleshooting/Using_the_Cisco_M... 

[PhilipDAth]

If you plug a notebook into the MX84 port does the link light come up?

Perhaps the MX84 port is disabled.

Does anything appear in the Cisco switches log when you plug the MX84 into it?

[SimonT]

I have requested the logs for the other device, my guess is that its a port negotiation issue as soon as I am back on site I can test and confirm what happens when a notebook is plugged in as well as the port speed.

[SimonT]

On Monday I logged in to find that the port was now active, strange that nothing changed between Saturday and Monday but the port is showing as active and I can ping the remote host.

[Jason7]

Hi @SimonT 

We have been experiencing this very same issue at one of our sites. Symptoms are identical, both the MX and Cisco switch are set to auto duplex/speed and the port will not come up. Plug a laptop into either the MX or the switch and the port comes straight up. Often then plugging the MX back to the switch and it will then work. Once up it will work without issue until the unit is powered down for maintenance. We also had a very similar experience where the port would not come up and then over a weekend after leaving the devices connected we found the port had come up.

As has been mentioned seemed to be some strange negotiation issue, we assume a bug but unsure if the bug sits on the MX or switch side.

We have a Meraki MX84 (ver. 15.44) and a Cisco C2960X (ver. 12.2(2)E8), out of interest what are you running in your environment?

We have yet to try fixing the port speeds/duplex on both sides or upgrading the switch IOS. The issue is once the port comes back up the device is then in use so we don't get the chance to troubleshoot.

Interested to hear if any others experience similar issues. @Meraki2 Any other reports you have seen of this on your side?

Jason