Layer 2 Switching Commands 287MAC Address Table CommandsDell EMC Networking N1100-ON/N1500/N2000/N2100-ON/N3000/N3100-ON/N4000 Series SwitchesDell EMC Networking switches implement a MAC Learning Bridge iscompliance with IEEE 802.1Q. The switches implement independent VLANlearning (IVL). Dynamically learned MAC addresses are used to filter the setof ports on which a frame is forwarded within a VLAN, that is, the destinationMAC address and ingress VLAN for a frame entering the switch is looked upin the MAC address table and, if a match is found, the frame is forwarded outthe matching port(s). If no match is found, the frame is flooded out all portsin the VLAN except for the ingress port.When a frame is received on a port, the source MAC address (and VLAN) islooked up in the MAC address table. If no matching entry is found, a newentry is added to the MAC address table associated with the source port. If amatching entry is found, the matching entry timestamp is refreshed such thatit will continue to remain in the MAC address table. Dynamic MAC addressentries for which no frames have been received within the aging period areremoved out of the MAC address table. The administrator can globallyconfigure the MAC address aging timer.Administrators can configure static MAC address entries. Static MAC entriesare treated in the same manner as dynamic MAC address entries for thepurposes of frame forwarding. Static MAC addresses never age out of theMAC address database and can only be removed by administrator action.Port security allows the administrator to disable learning of MAC addresseson selected interfaces. Dynamically learned MAC addresses are flushed on aninterface at the time port security is enabled. The interface then dynamicallylearns MAC addresses up to the configured limit and no more. Theadministrator may configure a limit of 0 in order to disable MAC learning onthe interface entirely. In this configuration, it is advisable to configure staticMAC entries on the interface in order to facilitate forwarding.
