If a custom MTU size has been configured on on-premises port groups, it’s important to recheck the MTU size and packet defragmentation after migrating to VMware Cloud on AWS.
For now, the default MTU size for inter-SDDC networks is 8950 and is configurable on Direct Access based connections (should be set equally on all VIFs). For VPN based connections, the MTU, disregard of all configurations, will be 1500. After changing the MTU size (switching to jumbo frames), always test the final configuration to ensure that no defragmentation is happening along the path: defragmentation might have higher negative impact on the performance compared to gains from using jumbo frames.
For example, on a Windows Operating system use the ping -f -l <packet size> command to check the maximum packet size that can be transferred without defragmentation.