Configuring a VLAN MAC address with heartbeat interval

When installing routing switches in place of existing routers in a network configuration, you can achieve Layer 3 VLAN migration by using the ip-recv-mac-address command at the VLAN configuration level to:
  • Configure the MAC address of the previously installed router on each VLAN interface of a routing switch.

  • Optionally configure the time interval to use for sending heartbeat packets with the configured MAC address.


ip-recv-mac-address <mac-address> [interval <seconds>]

no ip-recv-mac-address <mac-address> [interval <seconds>]

ip-recv-mac-address <mac-address>

Configures a VLAN interface with the specified MAC address. Enter the no version of the command to remove the configured MAC address and return to the original MAC address of the switch.

interval <seconds>

(Optional) Configures the time interval, in seconds (1 to 255, default: 60), used between transmissions of heartbeat packets to all network devices configured on the VLAN.

Operating notes

  • Enter the no form of the command to remove a configured MAC address and restore the default MAC address of the switch.

  • The ip-recv-mac-address command lets you configure only one MAC address for a specified VLAN. If you re-enter the command to configure another MAC address, the previously configured MAC address is overwritten.

  • When you configure a VLAN MAC address, you may also specify a heartbeat interval. The interval <seconds> parameter is optional.

  • After you configure a VLAN MAC address:
    • IP router and MAC ARP replies to other VLAN devices contain the user-defined MAC address as the Ethernet sender hardware address.

    • Outbound VLAN traffic contains the Switch MAC address, not the configured MAC address, as the source MAC address in packet headers.

  • Immediately after you configure a VLAN MAC address or remove a configured MAC address, a gratuitous ARP message is broadcast on the connected segment to announce the change of the IP-to-MAC address binding to all connected IP-based equipment.

  • A configured VLAN MAC address supports proxy ARP and ARP.

  • A new MIB variable, ifRcvAddressTable, is introduced to support VLAN MAC configuration.

  • You cannot configure a VLAN MAC address using the WebAgent. You must use the CLI.

  • VRRP is not supported on a VLAN interface with a user-configured MAC address.

Configuring a MAC address

The following example shows how to configure a MAC address on VLAN 101.

switch# configure terminal
switch(config)# vlan 101
switch(vlan-101)# ip-recv-mac-address 0060b0-e9a200 interval 100

Verifying a VLAN MAC address configuration

To verify the configuration of Layer 3 MAC addresses on the VLAN interfaces of a switch, use the show ip-recv-mac-address command.