Overview
The MACVLAN provides a means to create multiple virtual network interfaces, each with its own unique Media Access Control (MAC) address, attached to a physical network interface. This technology is utilized to address specific network requirements, such as obtaining multiple IP addresses or establishing distinct PPPoE client connections from a single physical Ethernet interface while using different MAC addresses. Unlike traditional VLAN (Virtual LAN) interfaces, which rely on Ethernet frames tagged with VLAN identifiers, MACVLAN operates at the MAC address level, making it a versatile and efficient solution for specific networking scenarios.
A MACVLAN interface can only receive broadcast packets, packets addressed to its own MAC address, and a limited number of multicast addresses. If the physical interface has a VLAN configured, the MACVLAN interface cannot receive packets from that VLAN.
For bridging and more complex Layer2 solutions involving VLANs, a dedicated switch should be used instead.
Basic Configuration Example
Picture a scenario where the ether1 interface connects to your ISP, and your router needs to lease two IP addresses, each with a distinct MAC address. Traditionally, this would require the use of two physical Ethernet interfaces and an additional switch. However, a more efficient solution is to create a virtual MACVLAN interface.
To create a MACVLAN interface, select the needed Ethernet interface. A MAC address will be automatically assigned if not manually specified:
/interface macvlan add interface=ether1 name=macvlan1 /interface macvlan print Flags: R - RUNNING Columns: NAME, MTU, INTERFACE, MAC-ADDRESS, MODE # NAME MTU INTERFACE MAC-ADDRESS MODE 0 R macvlan1 1500 ether1 76:81:BF:68:69:83 bridge
Now, a DHCP client can be created on ether1 and macvlan1 interfaces:
/ip dhcp-client add interface=ether1 add interface=macvlan1
Property Reference
Sub-menu: /interface/macvlan
Configuration settings for the MACVLAN interface.
| Property | Description |
|---|---|
| arp (disabled | enabled | local-proxy-arp | proxy-arp | reply-only; Default: enabled) | Address Resolution Protocol setting
|
| arp-timeout (auto | integer; Default: auto) | Sets for how long the ARP record is kept in the ARP table after no packets are received from IP. Value auto equals to the value of arp-timeout in /ip/settings/, default is 30s. |
| comment (string; Default: ) | Short description of the interface. |
| disabled (yes | no; Default: no) | Changes whether the interface is disabled. |
| interface (name; Default: ) | Name of the interface on top of which MACVLAN will work. MACVLAN interfaces can be created on Ethernet or VLAN interfaces, adding VLAN on MACVLAN is not supported. |
| loop-protect (on | off | default; Default: default) | Enables or disables loop protect on the interface, the default works as turned off. |
| loop-protect-disable-time (time interval | 0; Default: 5m) | Sets how long the selected interface is disabled when a loop is detected. 0 - forever. |
| loop-protect-send-interval (time interval; Default: 5s) | Sets how often loop protect packets are sent on the selected interface. |
| mac-address (MAC; Default: ) | Static MAC address of the interface. A randomly generated MAC address will be assigned when not specified. |
| mode (private | bridge; Default: bridge) | Sets MACVLAN interface mode:
|
| mtu (integer; Default: 1500) | Sets Layer 3 Maximum Transmission Unit. For the MACVLAN interface, it cannot be higher than the parent interface. |
| name (string; Default: ) | Interface name. |