MikroTik bridge setup: joining ports into one network

Last updated: 2 October 2026

A bridge joins several ports into one network, the way a switch does. Every port in the bridge shares the same address range, DHCP server and hotspot. The one rule to remember: once a port is in a bridge, everything is configured on the bridge, not on the port.

Before you change a live router: take a backup (how) and turn on Safe Mode in Winbox, so a mistake that locks you out is undone by itself.

1. Create the bridge and add ports

/interface bridge add name=bridge-lan
/interface bridge port add bridge=bridge-lan interface=ether2
/interface bridge port add bridge=bridge-lan interface=ether3
/interface bridge port add bridge=bridge-lan interface=ether4

Wi-Fi interfaces are added the same way (for example interface=wlan1). Do not add the internet port. Do not add the port you are connected through as the first step on a live router without Safe Mode: the moment a port joins a bridge, an address that sits on the port stops working properly.

2. Move the address and DHCP server to the bridge

If ether2 had the LAN address and the DHCP server before, move both:

/ip address set [find interface=ether2] interface=bridge-lan
/ip dhcp-server set [find interface=ether2] interface=bridge-lan

On an empty router, add them directly on the bridge instead:

/ip address add address=192.168.88.1/24 interface=bridge-lan
/ip pool add name=lan-pool ranges=192.168.88.10-192.168.88.254
/ip dhcp-server add name=lan-dhcp interface=bridge-lan address-pool=lan-pool disabled=no
/ip dhcp-server network add address=192.168.88.0/24 gateway=192.168.88.1 dns-server=192.168.88.1

The full DHCP steps are in DHCP server setup.

Why services must sit on the bridge

A port inside a bridge is a "slave": packets that come in are handed to the bridge, and the router sees them as arriving on the bridge. Anything attached to the port itself never sees them. That is why:

a DHCP server on a bridge port is shown in red in Winbox and gives no addresses;
a hotspot on a bridge port never shows the login page (see hotspot login page not opening);
a PPPoE server on a bridge port gets no customers;
firewall rules with in-interface=ether2 stop matching. Use in-interface=bridge-lan.

Find leftovers that still point at a port:

/interface bridge port print
/ip address print
/ip dhcp-server print
/ip hotspot print

Hardware offload

On routers with a switch chip, traffic between ports of the same bridge can be passed by the chip without using the processor. Ports that do this show the H flag:

/interface bridge port print

It is on by default (hw=yes on each port). Some settings turn it off for a bridge, among them bridge firewall filters, and on some models VLAN filtering or a second bridge on the same switch chip. Without it the bridge still works, only slower and with more processor load. One bridge per router is the safe choice; if you need separate networks on one bridge, use VLANs.

Loops and STP, in a sentence

If two ports of the same bridge are joined by a cable or through a switch, traffic circles forever and the network stops; the bridge's spanning tree protocol (RSTP by default) detects this and shuts one of the ports.

/interface bridge print
/interface bridge set bridge-lan protocol-mode=rstp

Two separate networks

For a private LAN and a customer network, make two bridges with different address ranges, for example bridge-lan and bridge-hotspot, and put each port in one of them. A port can only be in one bridge.

Check

/interface bridge host print
/ip dhcp-server lease print
/ping 192.168.88.10 count=3

The host list shows which MAC address is behind which port, which is the quickest way to find where a device is plugged in.

Where RadiusNest fits

Bridges are plain router setup and RadiusNest does not change them. It matters in one place: the hotspot or PPPoE server that RadiusNest checks logins for must run on the bridge, not on one of its ports, exactly as described above.

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Questions and answers

Why is my DHCP server red after I added the port to a bridge?

The DHCP server is still attached to the port. Set its interface to the bridge and it turns black and starts giving addresses.

Does a bridge slow the router down?

Not when hardware offload is active, shown by the H flag on the ports. Without it, traffic between the ports uses the processor.

Can one port be in two bridges?

No. A port belongs to one bridge. To carry several networks over one port, use VLANs.

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