D-Link DES-3326 User Manual - Subnet Masks to Vlans
DES-3326 Layer 3 Fast Ethernet Switch User’s Guide
Configuring the Switch Using the Console Interface
117
Layer 3 VLANs must be configured on the switch before they can
be assigned IP subnets. Further, the static VLAN configuration is
specified on a per port basis. On the DES-3326, a VLAN can
consist of end-nodes – just like a traditional layer 2 switch, but a
VLAN can also consist of one or more layer 2 switches – each of
which is connected to multiple end-nodes or network resources.
So, a Layer 3 VLAN, consisting of 4 ports, could be connected to 4
layer 2 switches. If these layer 2 switches each have 24 ports, then
the Layer 3 VLAN would contain 4 x 24 = 96 end nodes. Assigning
an IP subnet to the Layer 3 VLAN would allow wire-speed IP
routing from the WAN to each end node and between end nodes.
So, the IP subnets for a network must be determined first, and the
VLANs configured on the switch to accommodate the IP subnets.
Finally, the IP subnets can be assigned to the VLANs.
Assigning IP Network Addresses and
Subnet Masks to VLANs
The DES-3326 allows the assignment of IP subnets to individual
VLANs. Any VLAN configured on the switch that is not assigned
an IP subnet, will behave as a layer 2 VLAN and will not be
capable of IP routing – even if the switch is in IP Routing mode.
Developing an IP addressing scheme is a complex subject, but it is
sufficient here to mention that the total number of anticipated end
nodes – for each Layer 3 VLAN – must be accommodated with an
unique IP address. It should be noted that the switch regards a
VLAN with an IP network address and corresponding subnet mask
assigned as an IP interface in IP Routing mode.
Note: See the section titled IP Addressing and
Subnetting in Chapter 5 for more information.