Netgear XCM8806 Chassis User Manual - Page 272

NETGEAR 8800 User Manual FDB Contents Each Forwarding Database (FDB) entry consists of: • The MAC address of the device • An identifier for the port and VLAN on which it was received • The age of the entry • Flags Frames destined for MAC addresses that are not in the FDB are flooded to all members of the VLAN. How FDB Entries Get Added The MAC entries that are added to the FDB are learned in the following ways: • On NETGEAR 8800 series switches, MAC entries can be learned at the hardware level. • Virtual MAC addresses embedded in the payload of IP ARP packets can be learned when this feature is enabled. • Static entries can be entered using the command line interface (CLI). • Dynamic entries can be modified using the command line interface (CLI). • Static entries for switch interfaces are added by the system upon switch boot-up. The ability to learn MAC addresses can be enabled or disabled on a port-by-port basis. You can also limit the number of addresses that can be learned, or you can lock down the current entries and prevent additional MAC address learning. NETGEAR 8000 series modules support different FDB table sizes. On a NETGEAR 8800 switch with a variety of modules, the FDB tables on some modules can be filled before the tables on other modules. In this situation, when a lower-capacity FDB table cannot accept FDB entries, a message appears that is similar to the following: HAL.FDB.Warning> MSM-A: FDB for vlanID1 mac 00:00:03:05:15:04 was not added to slot 3 - table full. Note: For information on FDB tables sizes, see the NETGEAR 8800 Release Notes. FDB Entry Types The following sections describes the types of entries that can exist in the FDB: • Dynamic Entries on page 273 • Static Entries on page 273 • Blackhole Entries on page 274 272 | Chapter 10. FDB