The HCX Mobility Optimized Networking (MON) feature routes network traffic based on locality of the source and destination virtual machines. MON operation requires specific configuration of the HCX Network Extension parameters and the network environment between the source and the destination sites.
When using HCX Mobility Optimized Networking, some configurations are not supported.
Unsupported Configurations for all HCX Deployment
- Virtual Machines with more than a single vNIC connected to cloud segments or other stretched segments that are MON enabled.
- Extended segments that rely on DHCP services provided on the source gateway for the segment.
- Optimization of traffic between MON-enabled migrated virtual machines to virtual machines on extensions without MON.
- Intra-VLAN traffic (virtual machine traffic within one VLAN or network) is not optimized.
- Deployments with large flat networks on-premises.
- Traffic optimizations within the on-premises network or source environment. The MON optimization functions happen within the destination SDDC only.
- Ingress optimization where the HCX injected virtual machine static routes cannot be learned by the source gateway for the MON enabled network.
- MON only supports traffic optimization between the extended subnet and cloud-local subnets that are directly connected to the same Ttier-1 router. Although reachability outside the Tier-1 can be configured, the traffic flows through the Tier-0 router are dependent on the SDDC network environment and the design implementation might not be supported.
- Some third-party implementations for First Hop Redundancy Protocol (FHRP) are not compatible with MON. Under these conditions, the on-premises Default Gateway Router MAC address cannot be identified, so cloud VMs with MON enabled cannot communicate to it. See VMware KB 85849.
Unsupported Configurations Specific to HCX for VMware Cloud on AWS deployments
- Any installation where the Mobility Optimized Networking segment properties from VMware Cloud on AWS "Networking & Security" tab must be modified.
- Installations where routes for migrated virtual machines are currently not advertised over Direct Connect or Transit Connect.
- Route-based VPN connections to native AWS VPCs. MON routes cannot be filtered and reaching the 100-route limit with VMware Cloud on AWS transitions the VPN to a down state.
- Optimization of traffic between MON-enabled migrated virtual machines and the SDDC management networks.
- Traffic between MON-enabled migrated virtual machines and Connected VPC Private IP addresses.
- Traffic between MON-enabled migrated virtual machines and virtual machines in other SDDCs (traffic over private Transit Connect).
- Traffic between MON-enabled migrated virtual machines across Multi-Tenancy Cloud Director Service boundaries.