create fdb vlan ports

create fdb mac_addr vlan vlan_name [ports port_list {tagged tag} | blackhole | vxlan { vr vr_name } {ipaddress} remote_ipaddress ] | broadcast vlan vlan_name vxlan { vr vr_name } {ipaddress} remote_ipaddress | unknown-multicast vlan vlan_name vxlan { vr vr_name } {ipaddress} remote_ipaddress | unknown-unicast vlan vlan_name vxlan { vr vr_name } {ipaddress} remote_ipaddress ]


Creates a permanent static FDB (forwarding database) entry.

Syntax Description

mac_addr Specifies a device MAC address, using colon-separated bytes.
vlan_name Specifies a VLAN (Virtual LAN) name associated with a MAC address.
port_list Specifies one or more ports or slots and ports associated with the MAC address.
tagged tag Specifies the port-specific VLAN tag. When there are multiple ports specified in port_list, the same tag is used for all of them.
blackhole Enables the blackhole option. Any packets with either a source MAC address or a destination MAC address matching the FDB entry are dropped.
broadcast Forwarding destination(s) for broadcast traffic.
unknown-unicast Forwarding destination(s) for unknown unicast traffic.
unknown-unicast Forwarding destination(s) for unknown multicast traffic.
vxlan The MAC address is reachable through a VXLAN Tunnel.
vr VR/VRF instance the IPv4 address is configured on.
vr_name An existing VR/VRF name.
ipaddress Configure the IP address of the remote tunnel endpoint to which the MAC needs to be bound.
remote_ipaddress IPv4 address of the remote tunnel endpoint.



Usage Guidelines

Permanent entries are retained in the database if the switch is reset or a power off/on cycle occurs. A permanent static entry can either be a unicast or multicast MAC address. After they have been created, permanent static entries stay the same as when they were created. If the same MAC address and VLAN is encountered on another virtual port that is not included in the permanent MAC entry, it is handled as a blackhole entry. The static entry is not updated when any of the following take place:
  • A VLAN identifier (VLANid) is changed.
  • A port is disabled.
  • A port enters blocking state.
  • A port goes down (link down).
A permanent static FDB entry is deleted when any of the following take place:
  • A VLAN is deleted.
  • A port mode is changed (tagged/untagged).
  • A port is deleted from a VLAN.

Permanent static entries are designated by spm in the flags field of the show fdb output. You can use the show fdb command to display permanent FDB entries.

If the static entry is for a PVLAN VLAN that requires more than one underlying entry, the system automatically adds the required entries. For example, if the static entry is for a PVLAN network VLAN, the system automatically adds all required extra entries for the subscriber VLANs.

You can create FDB entries to multicast MAC addresses and list one or more ports. If more than one port number is associated with a permanent MAC entry, packets are multicast to the multiple destinations.

IGMP (Internet Group Management Protocol) snooping rules take precedence over static multicast MAC addresses in the IP multicast range (01:00:5e:xx:xx:xx) unless IGMP snooping is disabled.



When a multiport list is assigned to a unicast MAC address, load sharing is not supported on the ports in the multiport list.

In ExtremeXOS 21.1, this command was extended to add a remote VTEP as a destination to a MAC address. Three new tokens “broadcast”, “unknown-multicast” and “unknown-unicast” have been added to this command. When you want to specify a destination to forward all broadcast or unknown unicast traffic on that VLAN, these token are used. For “broadcast”, “unknown-multicast” and “unknown-unicast” only remote VTEPs (and not port_list or blackhole) can be specified in this release of EXOS. These entries can only be created when the virtual-network is in explicit-remote flooding mode.


The following command adds a permanent, static entry to the FDB for MAC address 00 E0 2B 12 34 56, in VLAN marketing on port 4 on a switch:

create fdb 00:E0:2B:12:34:56 vlan marketing port 4

The following example adds a permanent, static entry to the FDB for MAC address 00:01:02:03:04:05, in VLAN marketing, on a VLAN port that has tag 100 on port 3 on a switch:

create fdb 00:01:02:03:04:05 vlan msk ports 3 tag 100


This command was first available in ExtremeXOS 10.1.

The ability to create a multicast FDB with multiple entry ports was added in ExtremeXOS 11.3.

The blackhole option was first available for all platforms in ExtremeXOS 12.1.

In ExtremeXOS 12.3, the fdb keyword was introduced as an alias to the fdbentry keyword to avoid interference with the syntax of the MAC-Tracking feature commands. Both keywords execute; however, the syntax helper (tab completion) does not recognize the fdbentry keyword.

The tag keyword and example was added in ExtremeXOS 15.4.

Three new tokens “broadcast”, “unknown-multicast” and “unknown-unicast” were added to this command in ExtremeXOS 21.1.

Platform Availability

This command is available on the Summit X450-G2, X460-G2, X670-G2, X770, and ExtremeSwitching X440-G2, X620, X690, X870 series switches.