After a fresh deployment of an Azure Stack, you probably want to deploy Resource Provider like App Services with SQL Failover Cluster or Internal Load Balancers, if you encounter problems after that please read this.
If the Azs deployment prior version 1905, please check this bellow:
Warning: Please log a SR Ticket with Dell EMC Support to help if you want.
Issue: MTU problems on Internal Load Balancers on Dell EMC Azure stack
In deployments prior to 1905, the VLAN 7 MTU setting defaults to 1500 MTU, however in instances where you are using Internal Load Balancers it is expected that the packet can exceed 1500 bytes for our VXLAN encapsulation headers. In these scenarios where the packet may have exceeded 1500 bytes and Don’t Fragment is set, the packet will be dropped.
To check the current TOR 1&2 configuration setting, run: show running-config interface vlan 7 on each switch
To adjust the VLAN 7 MTU setting, you will need to run the following commands to update VLAN 7 MTU for both TOR devices.
interface vlan 7
copy run start