Hi.
I am using RB751U-2HnD, RouterOS 5.16.
I have a situation where I need 5 physical LAN ports, so with this router I need to configure my WAN port (port 1 for this router) to be another LAN port.
How do I do this? I can’t find a reference to this in the forums - if I missed it please just post the link.
Do I just open up Interfaces and change the port 1 interface definition to have a Master Port of ether2-master-local? I have a feeling there is more to it than that.
Thanks in advance.
Followup:
In the ‘Bridge’ tabI tried adding a port between ether1-gateway (ie port 1) and bridge-local. That seems to do the trick, or at least I can talk to the router now via port 1.
Is this the proper way of achieving this or is there more I need to know?
Thanks.
The RB750 series uses the Atheros7240 Hardware switching chip on only ports 2-5; So you’ll have to bridge ports 1 & 2 if you wish to use it in this way. Note that bridging increases CPU usage, where switched traffic does not.
Thanks for replying.
What you say makes sense. But when I try to create a new bridge via winbox or using a browser I don’t see where I specify the ports I want to bridge. I tried doing this via the bridge tab and the interfaces tab with the same results.
What am I missing?
You make a fair point about CPU usage. FWIW, our business application will not create a heavy load of network traffic so I believe we will be ok there.
Hmm, tried this via telnet interface referencing the following doc reference:
http://wiki.mikrotik.com/wiki/Manual:Interface/Bridge#Bridge_Interface_Setup
and the result was the same as if I added a port. Actually it wouldn’t let me add the 2nd interface - gave an error message. However, I can use the ether1 port and looking at winbox, routeros configuration is as if I added a port between ether1 and bridge-local.
I wish this made more sense to me. I don’t see how you can bridge anything without being able to specify what you are bridging.
spoke too soon. Adding a port to a bridge (no matter how I do it) causes the router to switch to bridge mode. 
I’m not sure what you mean by Bridge “mode”.
The basic steps are to ensure ports 3-5 have their master port set to port 2 in Winbox, thereby making them switched together. Then create a new bridge interface, and add ports 1 & 2 to the new bridge interface in the Bridge->Ports window.
Also note that any ports which are hardware-switched-slaves (3-5) will be unavailable for direct access by RouterOS. Only the master port 2 can be used, and it represents all the associated slave ports as well.
If you want direct access to each port you could alternatively remove the “master port” setting from ports 2-5, and place all 5 interfaces in one bridge.
Hope this helps.
Thanks for your help lordkappa