D-Link DES-3028 User Manual - Cpu Interface Filtering

DES-3028 DES-3028P DES-3052 DES-3052P Layer 2 Fast Ethernet Managed Switch 

CPU Interface Filtering 

Due to a chipset limitation and the need for extra switch security, the DES-30xx switch series incorporates CPU Interface 

filtering. This added feature increases the running security of the Switch by enabling the user to create a list of access rules for 

packets destined for the Switch’s CPU interface. Employed similarly to the Access Profile feature previously mentioned, CPU 

interface filtering examines Ethernet, IP and Packet Content Mask packet headers destined for the CPU and will either forward 

them or filter them, based on the user’s implementation. As an added feature for the CPU Filtering, the Switch allows the CPU 

filtering mechanism to be enabled or disabled globally, permitting the user to create various lists of rules without immediately 

enabling them. 

Creating an access profile for the CPU is divided into two basic parts. The first is to specify which part or parts of a frame the 

Switch will examine, such as the MAC source address or the IP destination address. The second part is entering the criteria the 

Switch will use to determine what to do with the frame. The entire process is described below. 

CPU Interface Filtering State  

In the following window, the user may globally enable or disable the CPU Interface Filtering mechanism by using the pull-down 

menu to change the running state. To access this window, click ACL > CPU Interface Filtering > CPU Interface Filtering 

State. Choose Enabled to enable CPU packets to be scrutinized by the Switch and Disabled to disallow this scrutiny. 

Figure 9- 15. CPU Interface Filtering State window 

CPU Interface Filtering Profile Table 

Click ACL > CPU Interface Filtering > CPU Interface Filtering Table to display the CPU Access Profile Table entries created 

on the Switch. To view the configurations for an entry, click the hyperlinked Profile ID number. 

Figure 9- 16. CPU Interface Filtering Table window 

To add an entry to the CPU Interface Filtering Profile Table window, click the Add button. This will open the CPU Interface 

Filtering Profile Configuration window, as shown below. There are three CPU Access Profile Configuration windows; one for 

Ethernet (or MAC address-based) profile configuration, one for IP address-based profile configuration and one for the Packet 

Content Mask. Users can switch between the three CPU Access Profile Configuration windows by using the Type drop-down 

menu. The window shown below is for Ethernet CPU Interface Filtering Configuration. 

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