[Observium] Port down and observium doesnt show same vlan traffic

Hello,

I am assign my cisco switch into observium. The cisco itself connect to internet thru port 48 on vlan 2. And observium server connect to cisco port 47 on vlan 3. There are several server connect to cisco vlan 2.

Here is my issue, once I unplug my internet connection(port 48). Other server traffic on vlan 2 doesn't show up on observium.

Anyone know whats the problem here ? Is it cisco settings or other ?

Thank you