ICX-7150-C12 static IP interface disappears from the network after 25 seconds after boot completes

[matthew_leonard]

I have an ICX 7150 C12 which has been running fine for over 2 years on 8.0.9.  Today I added an SPF+ RJ45 module to on of the uplink ports to see if I could use it to connect with my router, it didn't, of course, so i pulled the module out and reconnected the router cable back to port 1.  Issues began immediately.  

While my Ruckus APs were fine, I noticed certain VLANs stopped working.  I tried logging in to the 7150, but it did not show up nor even respond to a ping.  I rebooted again, this time after its boot sequence everything seemed fine - I could log in via web UI, it responded to pings... but only for about 20-30 seconds, then the switch itself disappears from the network.  Again, the Ruckus APs are fine and the connection to the ISP router is fine, so I have internet, but only via wifi.  I'm worried about a factory reset, as I do not recall how I was able to update the password correctly.  Should I attempt an upgrade to 9.0.0 to solve the issue?

I do not have any way to access this device via its serial console, only RJ45.  Unfortunately, the USB-C port does not seem to want to work with MacOS, which is all I have to connect with.  Having to wait 2m for a reboot and then quickly log in to the Web UI to check one thing on the menu before losing connection is painful, especially with teenagers who are stuck home for the summer and depend on the wifi...  I connected to the out-of-band port, but till no connectivity.

Did I inadvertently change some config by adding the SPF+ module?   How can I get into the boot console for this device via an RJ45 to USB-C ethernet on my mac?  (I do not recall how I did this 2y ago).  What logs should I check?  Should I quickly click command reload?  Would telnet work?