Chapter 6 Configuring VLANs 29
The physical LAN network consists of a switch, two servers, and five clients. The
LAN is logically organized into threedifferent VLANs, each representing a different
IP subnet.
■VLAN1 is an IP subnet consisting of the Main Server,Client 3, and Client 5. This
represents an engineering group.
■VLAN2 includes the Main Server,Clients 1 and 2 by means of a shared media
segment, and Client 5. This is a software development group.
■VLAN3 includes the Main Server,the Accounting Server, and Client 4. This is an
accounting group.
The Main Server is a high-use server that needs to be accessed from all VLANs and
IP subnets. The server has a Sun 10GbE XFP SR PCI ExpressCard installed. All three
IP subnets are accessed by means of the single physical Ethernet adapter interface.
The server is attached to one of the switch’s Gigabit Ethernet ports, which is
configured for VLANs1, 2, and 3. Both the Ethernet adapter and the connected
switch port have tagging turned on. Because of the tagging VLAN capabilities of
both devices, the server is able to communicate on all three IP subnets in this
network, but continues to maintain broadcast separation between all of those
subnets. The following list describes the components of this network:
■The Accounting Server is available to only VLAN 3. The Accounting Server is
isolated from all traffic on VLANs1 and 2. The switch port connected to the
server has tagging turned off.
■Clients1 and 2 are attached to a shared media hub that is then connected to the
switch. Clients 1 and 2 belong only to VLAN 2. Those clients arelogically in the
same IP subnet as the Main Server and Client 5. The switch port connected to this
segment has tagging turned off.
■Client 3 is a member of VLAN 1. This client can communicate only with the Main
Server and Client 5. Taggingis not enabled on Client 3’s switch port.
■Client 4 is a member of VLAN 3. This client can communicate only with the
servers. Taggingis not enabled on Client 4’s switch port.
■Client 5 is a member of both VLANs 1 and 2. This client has a Sun 10GbE XFP SR
PCI Express Card installed. Client 5 is connected to switch port 10. Both the
Ethernet adapter and the switch port are configuredfor VLANs 1 and 2, and both
have tagging enabled.
VLAN tagging is only requiredto be enabled on switch ports that create trunk links
to other VLAN-aware Ethernet switches, or on ports connected to tag-capable end-
stations, such as servers or workstations with VLAN-aware Ethernet adapters.