#ENABLE ROUTER ON A STICK MAC#
However, for a router, there is no advantage in generating unique MAC addresses per a VLAN subinterface, quite the contrary: it would require that the NIC controller supported multiple MAC addresses per physical port, a requirement increasing the cost and complexity of the NIC. Are you perhaps confusing this with the way old switches, not routers, worked? Old switches generated unique MAC addresses to make sure that the STP Bridge IDs for different per-VLAN STP instances were unique as well. In addition, I doubt that even the old IOSes created unique MAC addresses for VLAN subinterfaces. Simply put, to a switch, all frames on such link would belong to a single VLAN, irrespective of their source/destination MAC addresses. All it would see on its port are frames in a single VLAN (probably the native VLAN) sourced and destined from various MAC addresses. A switch does not expect nor support distinguishing VLANs based on source or destination MAC addresses. Your proposed mode of operation on the router requires that destination MAC addresses, not VLAN tags, are used to distinguish the VLAN from which the frame is coming into the router, and that source MAC addresses are used to distinguish the VLAN into which the frames are being forwarded out from the router, and that the frames are otherwise untagged. A switch port can operate only as an access port (without VLAN tags, VLAN membership statically determined by its configuration) or a trunk port (with VLAN tags, with VLAN membership determined on a per-frame basis using the VLAN tag in the frame). However, this would cause a disparity between the functionality provided and required by a switch and the functionality provided and required by a router. You are suggesting that if IOS generated a unique MAC address for each VLAN subinterface of a routed interface, VLAN tags would not be necessary on the link between the router and the switch because the particular subinterface for which incoming frames are intended would be identified simply by the unique destination MAC address in these frames. Setting Port 1 to Vlan Mode "enabled" and VLAN Header to "add if missing" makes Port 1 a trunk port.ģ.You have a very interesting idea on your mind here :) Unfortunately, it would not work - but the explanation will be slightly more lengthy. The VLAN page determines how the switch strips the Vlan tags with specific Vlan ID's from the packets as they exit these ports. Begin by clicking on the VLAN tab and make the following changes, assuming the trunk port will be Port1 (the port that is connected to the router).Ģ. You must be accessing the switch via ehter2 through ether5 since you are about to turn ether1 into a trunk port and you will lose communication with the switch at that point on ether1.ġ. NOTE: Before starting configuration, it is assumed you have 192.168.88.2 bound to your laptop and the switch is at the default Ip of 192.168.88.1. In this example we need two ports for devices on Vlan 30 on Ports 3 & 5 and one port for device on Vlan 40 on Port 4 and one port for a device on Vlan 20 on port 2. Selection of the Vlan ID and the assignment to the ports is your choice, decide what Vlan ID's you will use and where you will assign them. NOTE: Once you set port 1 to "trunk" mode, you will not longer be able to communicate with the switch unless you create a Vlan1 on your router. The way the OS is built, there is no need for a default gateway or a subnet mask. This behavior is a bit different than Cisco IOS that responds to untagged traffic via an IP bound to Vlan 1. Note that the switch will respond to http requests to its IP address on all ports. In this example we are using Vlan Id's 1, 20, 30 and 40. The default user name is admin with no password.Īll settings may be left at the defaults with the exception of a few. To log into the RB250GS switch, simply web browse to 192.168.88.1 from a computer on the same physical network segment with an IP on the same subnet, 192.168.88.0/24. The purpose of this article is to show the steps required to setup the MikroTik RB250GS switch as a trunked switch in the router-on-a-stick configuration. In practice, this same configuration can be used between two switches or two routers. In this example, a router with a single Ethernet interface is trunked to a MikroTik switch.