SG350 randomly reconfiguring interfaces

[waltreed]

I have a number of SG300 and SG350 switches which are all exhibiting this odd behavior.

For example, I will configure an interface like so:

interface GigabitEthernet1
 switchport mode trunk
 switchport trunk native vlan 22
!

After moving the switch to its final location and connecting it to another switch, the configuration changes to:

interface GigabitEthernet1
 spanning-tree link-type point-to-point
 switchport mode trunk
 macro description switch
 !next command is internal.
 macro auto smartport dynamic_type switch
!

Why is this interface getting reconfigured? How can I disable that behavior? It's causing serious problems that these switches are randomly re-configuring explicitly defined interfaces with a configuration that BREAKS connectivity.

[Max Harbin · Accepted solution]

From the output, of the port configuration, it looks like you have the Auto Smart port feature enabled. It can be Enabled/Disabled globally. Please Check out Chapter 10 of the Admin Guide for further details about Smartports and the configurations: 

WEBUI - 

https://www.cisco.com/c/dam/en/us/td/docs/switches/lan/csbms/350xg/admin_guide/AG_Tesla_350_550.pdf 

If you are configuring via CLI, it would be the macro commands in Chpater 38

CLI - 

https://www.cisco.com/c/dam/en/us/td/docs/switches/lan/csbms/350_/cli_guide/CLI_Tesla_Sx350_2_2_5.pdf 

Hope this helps,

Max

[waltreed]

Yes, that was it precisely. As a feature request, it would be nice if the smartport macros were disabled by default. I now have to go fix about 100 switches or so which have had random configuration changes due to Smartport macros. While I can see where smartports can be a useful concept, the reality is that it's rarely used and non-intuitive to have an explicitly configured interface get that configuration wiped out by an automated system.

[AR Vill]

"no macro auto smartport" command inside the interface will disable the smartport. The switch will not reconfigure the interface every time you disconnect and connect network devices on the switch-port