Oracle ATLS2XGF, User Manual

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Chapter 8 Configuring VLANs 63
Gigabit Ethernet ports, which is configured for VLANs 1, 2, and 3. Both the adapter
and the connected switch port have tagging turned on. The tagging VLAN
capabilities of both devices enable the sever to communicate on all three IP subnets
in this network, yet continue to maintain broadcast separation among the three
subnets. The following list describes the components of this network:
■
The Accounting Server is available to VLAN 3 only. It is isolated from all traffic
on VLANs 1 and 2. The switch port connected to the server has tagging turned
off.
■
Clients 1 and 2 are attached to a shared media hub that is then connected to the
switch. They belong to VLAN 2 only, and are logically 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, and can communicate only with the Main Server
and Client 5. Tagging is not enabled on Client 3’s switch port.
■
Client 4 is a member of VLAN 3, and can communicate only with the servers.
Tagging is not enabled on Client 4’s switch port.
■
Client 5 is a member of both VLANs 1 and 2, and has a Sun x8 Express Dual 10
Gigabit Ethernet Fiber XFP Low Profile Adapter installed. It is connected to
switch port 10. Both the adapter and the switch port are configured for VLANs 1
and 2 and have tagging enabled.
VLAN tagging is only required to 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 adapters.
Configuring VLANs in a Solaris
Environment
VLANs can be created according to various criteria, but each VLAN must be
assigned a VLAN tag or VLAN ID (VID). The VID is a 12-bit identifier between 1
and 4094 that identifies a unique VLAN. For each network interface (
nxge0 and
nxge1
), 4094 possible VLAN IDs can be selected. Only 512 unique IDs can be used
simultaneously. Because IP subnets are commonly used, it is best to use IP subnets
when setting up a VLAN network interface. This means that each VID assigned to a
VLAN interface of a physical network interface will belong to different subnets.
Tagging an Ethernet frame requires the addition of a tag header to the frame. The
header is inserted immediately following the destination MAC address and the
Source MAC address. The tag header consists of two bytes of Ethernet Tag Protocol
identifier (TPID, 0x8100) and two bytes of Tag Control Information (TCI).
FIGURE 8-2
shows the Ethernet Tag Header format.