Allied Telesis AT-S25 - Manual (Page 146)

Introduction to Virtual LANs
146
Drawbacks to
Port-based
VLANs
There are several drawbacks to port-based VLANs:
❑ It is not easy to share network resources, such as servers and
printers, across multiple VLANs. A router must be added to the
network to provide a means for interconnecting the port-based
VLANs.
❑ The introduction of a router into your network could create
security issues from unauthorized access to your network.
❑ A VLAN that spans several switches will require a port on each
switch for the interconnection of the various parts of the VLAN.
For example, a VLAN that spans three switches would require one
port on each switch just to interconnect the various sections of
the VLAN. In network configurations where there are many
individual VLANs that span switches, many ports can end up
being used ineffectively just to interconnect the various VLANs.