You can configure the Management Server virtual machine and the DB Name Server virtual machine with one network gateway.

The Management Server virtual machine uses the gateway associated with its Web Console Network Adapter. The DB Name Server virtual machine uses the gateway associated with its DB Name Service Network Adapter. If any network traffic that originates from the Management Server and DB Name Server virtual machines requires routing, that routing can be done only through the configured gateway. Network setups that require more than one gateway in either the Management Server or DB Name Server virtual machine are not currently supported and cannot be configured.