Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide - Manual (Page 367)

For configuration information, refer to VLAN groups and virtual routing interface group on page 394.
Dynamic, static, and excluded port membership
When you add ports to a protocol VLAN, IP subnet VLAN, IPX network VLAN, or AppleTalk cable
VLAN, you can add them dynamically or statically:
• Dynamic ports
• Static ports
You also can explicitly exclude ports.
Dynamic ports
Dynamic ports are added to a VLAN when you create the VLAN. However, if a dynamically added port
does not receive any traffic for the VLAN protocol within ten minutes, the port is removed from the
VLAN. However, the port remains a candidate for port membership. Thus, if the port receives traffic for
the VLAN protocol, the device adds the port back to the VLAN.
After the port is added back to the VLAN, the port can remain an active member of the VLAN up to 20
minutes without receiving traffic for the VLAN protocol. If the port ages out, it remains a candidate for
VLAN membership and is added back to the VLAN when the VLAN receives protocol traffic. At this
point, the port can remain in the VLAN up to 20 minutes without receiving traffic for the VLAN protocol,
and so on.
Unless you explicitly add a port statically or exclude a port, the port is a dynamic port and thus can be
an active member of the VLAN, depending on the traffic it receives.
NOTE
You cannot configure dynamic ports in an AppleTalk cable VLAN. The ports in an AppleTalk cable
VLAN must be static. However, ports in an AppleTalk protocol VLAN can be dynamic or static.
The following figure shows an example of a VLAN with dynamic ports. Dynamic ports not only join and
leave the VLAN according to traffic, but also allow some broadcast packets of the specific protocol to
"leak" through the VLAN. Refer to
Broadcast leaks on page 370.
Dynamic, static, and excluded port membership
FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide 367
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