https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/6-x/high_availability/guide/b_Cisco_Nexus_9000_Series_NX-OS_High_Availability_and_Redundancy_Guide/b_Cisco_Nexus_9000_Series_NX-OS_High_Availability_and_Redundancy_Guide_chapter_01.html  M. ... View more

   - I don't see any problems , these messages are informational.  M. ... View more

   - Whilst it also depends on the further layout of the Wifi infrastructure such as controller based using port channels and redundancy (or not); this message can be ignored.  M. ... View more

   = Perhaps this is a defensive action from the network infrastructure involved.   M. ... View more

>... >This means that the switch sends a packet to our radius-server  - Not at all!  There will always be activity in your firewall logs when you access the web-interface of the Catalyst for whatever reason (network traffic) . You  are deviating from the real problem which I already explained.  M. ... View more

   - If the radius servers sees no incoming authorization request, when the web interface is tried  , then it means that there is something wrong with the intended and or needed configuration on the switch (I am afraid).  M. ... View more

   - Check the radius server's authentication logs when this is tried ; if there's no activity then the auth-setup is (still) incorrect.  M. ... View more

   - Probably a bug ; you can issue the command session 4 in order to logon to that stack member and check the software version.  M. ... View more

  >.... Version 16.6.4a, RELEASE SOFTWARE   I can't see any conflict in this output.  M. ... View more

   - We have seen regular issues with Chromebooks in the forum. For starters don't disallow the lower data  rates in your WiFi environment because the apparently sometimes insist that they are available.  M. ... View more

- Acknowledged but be aware : it may become difficult to keep up in high redundancy environments ; suppose the server is connected to a dual-homed fex behind a nexus vpc pair with hsrp etc... Not applying the access list on all needed components may need to cheese holes permitting access anyway. Better is to separate app/servers and clients with Intranet firewalling solutions.  M. ... View more

   - The only option in this case is to have local firewalling on the intended server  M. ... View more

   - I found a link below which you may want to browse too :   https://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/nx-os/tech_note/vpc_upgrade.html  M. ... View more

   - Difficult to tell , as far as I can see you didn't include the nexus model (types) in your post. Also from which to which versions are you hopping to ? Carefully study release notes, for the  intended version you want to end up with. Sometimes intermediate  upgrades are needed on the nexus platform.  M. ... View more