How Fdb Entries Get Added; Associating A Qos Profile With An Fdb Entry - Extreme Networks 200 Series Installation And User Manual

Forwarding Database (FDB)
interface are stored as permanent. The Summit 200 series switches support a maximum of 64
permanent entries.
Once created, permanent entries stay the same as when they were created. For example, the
permanent entry store is not updated when any of the following take place:
— A VLAN is deleted.
— A VLAN identifier (VLANid) is changed.
— A port mode is changed (tagged/untagged).
— A port is deleted from a VLAN.
— A port is disabled.
— A port enters blocking state.
— A port QoS setting is changed.
— A port goes down (link down).
• Blackhole entries—A blackhole entry configures the switch to discard packets with a specified MAC
destination address. Blackhole entries are useful as a security measure or in special circumstances
where a specific destination address must be discarded. Blackhole entries are treated like permanent
entries in the event of a switch reset or power off/on cycle. Blackhole entries are never aged-out of
the database.

How FDB Entries Get Added

Entries are added into the FDB in the following two ways:
• The switch can learn entries. The system updates its FDB with the source MAC address from a
packet, the VLAN, and the port identifier on which the source packet is received. In a stacked
configuration, each switch manages its own FDB as well as its FDB tables.
• You can enter and update entries using a MIB browser, an SNMP Network Manager, or the
command-line interface (CLI).

Associating a QoS Profile with an FDB Entry

You can associate a QoS profile with a MAC address (and VLAN) of a device that will be dynamically
learned. The FDB treats the entry like a dynamic entry (it is learned, it can be aged out of the database,
and so on). The switch applies the QoS profile as soon as the FDB entry is learned.
NOTE
For more information on QoS, refer to Chapter 12.
110 Summit 200 Series Switch Installation and User Guide