Specifications

84 ExtremeWare XOS 11.0 Concepts Guide
Virtual LANs
Figure 3 illustrates two VLANs spanning two switches. On system 2, ports 25 through 29 are part of
VLAN Accounting; ports 21 through 24 and ports 30 through 32 are part of VLAN Engineering. On
system 1, all port on slot 1 are part of VLAN Accounting; all ports on slot 8 are part of VLAN
Engineering.
Figure 3: Two port-based VLANs spanning two switches
VLAN Accounting spans system 1 and system 2 by way of a connection between system 2, port 29 and
system 1, slot 1, port 6. VLAN Engineering spans system 1 and system 2 by way of a connection between
system 2, port 32, and system 1, slot 8, port 6.
Using this configuration, you can create multiple port-based VLANs that span multiple switches, in a
daisy-chained fashion. Each switch must have a dedicated port for each VLAN. Each dedicated port
must be connected to a port that is a member of its VLAN on the next switch.
Tagged VLANs
Tagging is a process that inserts a marker (called a tag) into the Ethernet frame. The tag contains the
identification number of a specific VLAN, called the VLANid.
NOTE
The use of 802.1Q tagged packets may lead to the appearance of packets slightly bigger than the
current IEEE 802.3/Ethernet maximum of 1,518 bytes. This may affect packet error counters in other
devices and may also lead to connectivity problems if non-802.1Q bridges or routers are placed in the
path.
EX_063
System 1
System 2
Accounting Engineering