Hello
I opened a case to mikrotik because I own an old CSS326 (manufactured with 2.0p swos).
If anyone as the very similar issue, feel free to comment below as I will send them this topic.
I can upgrade from 2.0p to any swos version.
If I applied the same version or a newer one (with my running config), I loose webui access, the device does not answer to icmp but I have answer to arping.
If I reset the switch and try to do the same procedure with no custom config:
- 2.0p → 2.x: upgrade is OK, UI is available, ping is OK
- 2.x → 2.x (re-apply the same process), the switch reboot on stock firmware 2.0p
- 2.x → 2.y: the switch reboot on stock firmware 2.0p
Even if the webui is unavailable, packet switching seems to work.
Regards