Here is an excerpt from the 52XX User Guide discussing VLANs. User Guide link:  <ADMIN NOTE: Broken link has been removed from this post by Dell>   VLANs and Frame Tagging The PowerConnect 5224 switch supports IEEE 802.1Q-compliant virtual LANs (VLANs). This capability provides a highly efficient architecture for establishing VLANs within a network and for controlling broadcast/ multicast traffic between workgroups. Central to this capability is an explicit frame tagging approach for carrying VLAN information between interconnected network devices. With frame tagging, a four-byte data tag field is attached to frames that cross the network. The tag identifies to which VLAN the frame belongs. The tag may be added to the frame by the end station itself or by a network device, such as a switch. In addition to VLAN information, the relative priority of the frame in the network can be specified by the tag. VLANs provide greater network efficiency by reducing broadcast traffic, and they also allow you to make network changes without having to update IP addresses or IP subnets. VLANs inherently provide a high level of network security, since traffic must pass through a Layer 3 switch or a router to reach a different VLAN. The PowerConnect 5224 switch supports the following VLAN features: • Up to 255 VLANs based on the IEEE 802.1Q standard • Distributed VLAN learning across multiple switches using explicit or implicit tagging and GVRP (GARP VLAN Registration Protocol) • Port overlapping, allowing a port to participate in multiple VLANs • End stations that can belong to multiple VLANs • Passing traffic between VLAN-aware and VLAN-unaware devices • Four-level priority tagging • Link aggregation with VLANs You can use VLANs on the 5224 switch to isolate/segment traffic.  You will need a Layer 3 device (router) if you need to communicate between the different VLANs.  The 5224 does not have Layer 3 capabilities. It sounds like you will actually need a router with ACL features to block specific traffic to/from the DC in your network.   Hope this helps, Keep us updated if you can.
Hi,  I have a Dell 5224 which connect to Internet Router, DC and workstations are all on that switch, is it possible I can use VLAN to block Internet traffic from /to my DC but wont affect users to access AD and Datason the DC and still can access Internet?  Thanks 
Can I use VLAN to block internet traffic for Server?