MS120 - Firmware issues accessing Status Page - FIX FOUND

[JamesTIP]

Hi All,

As we have had multiple issues with Cisco Meraki MS-120 when accessing the local status which has occured on 4 of our units. This was raised with Meraki support directly and we have a known work around which involved a manual ARP Entry onto the laptop to be able change the management vlan etc to get the device online.

Below is what we used on a windows 11 laptop for reference, I hope it helps!

Assign Ethernet Address as

IP: 1.1.1.99

DG: 1.1.1.100

DNS: 1.1.1.100

SM: 255.255.255.0

Open CMD as Administrator.

Run:

netsh interface ipv4 show interfaces

Locate the IDX of the Ethernet interface e.g. 24

netsh interface ipv4 add neighbors <Insert IDX FIGURE> 1.1.1.100 <MAC Address of Switch>

arp -a (check there is a static ARP entry in for 1.1.1.100)

You should then be able to ping and access the switch via the mgmt page.

[DarrenOC]

Thank you for sharing @JamesTIP 

Hopefully this will save someone time and effort in the future 

[Tony-Sydney-AU]

Hi @JamesTIP 

Thanks for sharing. I'm curious about the firmware version your MS120 is running. This is a rather unusual behaviour. 

I mean, after a factory reset, if you configure 1.1.1.99 in your client host, there should be no need to hard code your switch mac address resolving to 1.1.1.100. I.e.: was the switch not responding to ARP?

[JamesTIP]

Hi @Tony-Sydney-AU 

We tried factory resetting both units (we had one replaced via RMA) 

When the host was configured to 1.1.1.99 it could not ping .100 or see any arp entries etc. We even tried via the mgmt port on the back with the laptop set to dhcp. 

I have setup 150+ of these switches over the past 18 months and not come across this issue so must be a recent issue with the firmware Meraki are sending out of the door with the MS-120.

[Tony-Sydney-AU]

Hi @JamesTIP ,

Thanks a lot for sharing. This workaround surely will help other MS130 owners.

I wonder if someone else has seen this behaviour (switch not responding to ARP) on other switch models.

In that collaboration spirit, I'm sharing here how to add the switch mac address to ARP in a MacOS or Linux Ubuntu.

1. Launch the Terminal application
2. Run command "sudo arp -s <IP address> <MAC address>"

E.g.: sudo arp -s 1.1.1.100 b8:ab:61:aa:bb:cc

• use sudo arp -a to display the local ARP table

Back to firmware aspect you mentioned, I did some research internally and found a similar behaviour in older firmware (below 16.8).

There's a combination of hardware and firmware/software conditions that could result in that behaviour (switch not replying to ARP).

So one MS130 had a really bad hardware and you had to process RMA as the workaround didn't work.

The other was onboarded to dahsboard and I supposed you upgraded to latest MS firmware 17.2.1 (as of this writing).

Let's see if see if someone else finds this behaviour on other models or firmware.