Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide - Manual (Page 387)

NOTE
You can disable VLAN membership aging of dynamically added ports. Refer to
Disabling membership
aging of dynamic VLAN ports on page 387).
Dynamic ports within any protocol VLAN age out after 10 minutes, if no member protocol traffic is
received on a port within the VLAN. The aged out port, however, remains as a candidate dynamic port
for that VLAN. The port becomes active in the VLAN again if member protocol traffic is received on that
port.
Once a port is re-activated, the aging out period for the port is reset to 20 minutes. Each time a member
protocol packet is received by a candidate dynamic port (aged out port) the port becomes active again
and the aging out period is reset for 20 minutes.
Disabling membership aging of dynamic VLAN ports
You can disable VLAN membership aging of ports that are dynamically assigned to protocol or subnet-
based VLANs. This feature resolves the connectivity issue that may occur in certain configurations
when protocol or subnet VLANs are configured with dynamic port membership.
NOTE
This issue does not occur with statically assigned VLAN memberships. Thus, enable this feature only if
your configuration includes dynamically assigned VLAN memberships for protocol or subnet VLANs.
To enable this feature, enter commands such as the following.
device(config)# vlan 10 by port
device(config-vlan-10)# interface ethernet 1/1 to 1/5
device(config-vlan-10)# ip-proto name IP_Prot_VLAN
device(config-vlan-ip-proto)# no-dynamic-aging
device(config-vlan-ip-proto)# write memory
These commands create an IP protocol VLAN and disable the VLAN membership aging of ports that
are dynamically assigned to the protocol VLAN.
Syntax: [no] no-dynamic-aging
Enter the no form of the command to disable this feature after it has been enabled.
By default, VLAN membership of dynamically assigned ports will age out after a period of time if no
packets belonging to that protocol or subnet VLAN are received by the CPU.
The output of the show running-config command indicates if the no-dynamic-aging feature is enabled
for a specific protocol or subnet VLAN.
Configuration guidelines for membership aging of dynamic VLAN ports
• You cannot dynamically add a port to a protocol VLAN if the port has any routing configuration
parameters. For example, the port cannot have a virtual routing interface, IP subnet address, IPX
network address, or AppleTalk network address configured on it.
• Once you dynamically add a port to a protocol VLAN, you cannot configure routing parameters on
the port.
• Dynamic VLAN ports are not required or supported on AppleTalk cable VLANs.
• When protocol VLANs with dynamic ports are configured, the output of the show running-config
command in the Router image will show the "dynamic" keyword. In the Switch image, the keyword is
not shown in the output of the show running-config command.
Disabling membership aging of dynamic VLAN ports
FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide 387
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