Specifications

FDB Configuration Examples
ExtremeWare XOS 11.0 Concepts Guide 105
• Permanent entries—Permanent entries are retained in the database if the switch is reset or a power
off/on cycle occurs. Permanent entries must be created by the system administrator through the CLI.
A permanent entry can either be a unicast or multicast MAC address.
Permanent entries may be static, meaning they do not age or get updated, or they may be dynamic,
meaning that they do age and can be updated via learning.
Permanent entries can have QoS profiles associated with the MAC address. A different QoS profiles
may be associated with the MAC address when it is a destination address (an egress QoS profile)
than when it is a source address (ingress QoS profile).
Disabling MAC Address Learning
By default, MAC address learning is enabled on all ports. You disable learning on specified ports using
the following command:
disable learning port [<port_list> | all]
If MAC address learning is disabled, only broadcast traffic, EDP traffic, and packets destined to a
permanent MAC address matching that port number, are forwarded. Use this command in a secure
environment where access is granted via permanent FDBs per port.
FDB Configuration Examples
The following example adds a permanent static entry to the FDB:
create fdbentry 00:E0:2B:12:34:56 vlan marketing port 3:4
The permanent entry has the following characteristics:
• MAC address is 00:E0:2B:12:34:56.
• VLAN name is marketing.
• Slot number for this device is 3.
• Port number for this device is 4.
If the MAC address 00:E0:2B:12:34:56 is encountered on any port/VLAN other than VLAN marketing,
port 3:4, packets from that source will be dropped.
Configuring the FDB Aging Time
You configure the aging time for dynamic FDB entries using the following command:
configure fdb agingtime <seconds>
If the aging time is set to zero, all aging entries in the database are defined as static, nonaging entries.
This means the entries will not age out, but non-permanent static entries can be deleted if the switch is
reset. Supported aging is between 15 and 1,000,000 seconds. The default is 5 minutes (300 seconds).