Deutsche Telekom Fiber with a MikroTik Router

Mon, 25 May 2026 00:00:00 +0000

I switched to Deutsche Telekom Glasfaser (FTTH) and wanted to keep my MikroTik router. No FritzBox, no rented hardware, just my own box talking to the ONT.

It took a couple of hours to get it working, and the journey involved a fair amount of trial and error. Here’s what I tried, what failed, and what finally worked.

The setup

Router: MikroTik hAP ac
ONT: Deutsche Telekom Modem 2 fiber box, ethernet out

			┌─────────┐ ┌─────┐ ┌──────────┐
│ Fiber │──fiber──│ ONT │──eth────▶│ MikroTik │
└─────────┘ └─────┘ │ ether1 │
 └──────────┘
		

What I tried (and failed)

Attempt 0: swap the modem

My old setup was straightforward: a DSL modem on ether1 (the WAN port), with the MikroTik running a DHCP client to get an IP from it.

Networking on nobe4

Deutsche Telekom Fiber with a MikroTik Router

The setup

What I tried (and failed)

Attempt 0: swap the modem