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@madduci
Last active February 27, 2025 21:31
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Deutsche Telekom FTTH Access with OpenWRT

Configuring Deutsche Telekom FTTH Access with OpenWRT

After looking for alternatves to the suggested Router from Telekom (AVM FritzBox and HUawei Speedport), I've discovered the possibility of configuring my existing OpenWRT Router to act as gateway to the Telekom FTTH (Fiber To The Home) Magenta Zuhause package.

TL;DR

The WAN interface must be configured as follows (see your Telekom letter):

  • Protocol: PPPoE
  • PAP/CHAP username:
  • PAP/CHAP password: Zugangskenntwort
  • VLAN: 7
  • MTU: leave empty (delete the default value 1500)

Requirements

Access Data

Old Contracts (Before 2024)

It's important to know the following information, before attempting any connection:

  • Anschlusskennung
  • Zugangsnummer
  • Mitbenutzernummer
  • Zugangskenntwort

All the above information are typically sent by Telekom at home, when activating the Internet Access.

Newer Contracts (From 2024)

The "Easy Login" option is automatically activated for new contracts. If it is activated, you can use any username/password. Otherwise it can activated in the "Kundencenter".

Otherwise it's important to know the following information, before attempting any connection:

Anschlusskennung
Zugangsnummer
Mitbenutzernummer
Zugangskenntwort

All the above information can be found oin the "Kundencenter" at "Verträge" -> "Erweiterte Optionen" -> "Internetzugang".

Hardware

You need a OpenWRT-capable router (e.g. TP-Link Archer C7 works really well), see here for an exhaustive list of supported devices.

Make sure your Telekom Fiber Modem is working properly.

Configuration

Enable VLAN

The Telekom PPPoE access requires the VLAN-ID to be set to 7. In order to do so, you have to configure the Router Ethernet interface that refers to WAN. The configuration panel can be found under the Menu entry Network->Switch (on OpenWRT 22.03 is Network -> Devices -> Add Device Config)

In this panel, you can see a table showing the VLAN(s) configured for your Router (typically 2) and they have some comboboxes with status tagged/untagged/off. One of the VLANs configured should be configured with the following information:

Port Status CPU (eth0) LAN1 LAN2 LAN3 LAN4 WAN
1 tagged untagged untagged untagged untagged off
7 tagged off off off off tagged

In case of Routers with multiple Ethernet interfaces (e.g. TP-Link Archer C7), the panel should look like this:

Port Status CPU (eth0) CPU (eth0) LAN1 LAN2 LAN3 LAN4 WAN
1 tagged tagged untagged untagged untagged untagged off
7 tagged tagged off off off off tagged

Setup WAN Interface

In the Menu entry Network->Interfaces, select the WAN interface and set the following information in the General Setup tab:

  • Protocol: PPPoE
  • PAP/CHAP username: [email protected]
  • PAP/CHAP password: Zugangskenntwort

In the tab Physical Settings, select the interface Switch VLAN eth0.7 (the one corresponding to the VLAN-ID 7).

Beware: in case your "Zugangsnummer" has less than 12 digits, the PAP/CHAP username is in the form AnschlusskennungZugangsnummer#[email protected] (see https://telekomhilft.telekom.de/t5/Telefonie-Internet/PPPOE-Einwahl-ueber-einen-Router-herstellen/ta-p/3654990 for further details)

Performance Tuning

MTU should not be set to an MTU of 1500 in any WAN, PPPOE-WAN or VLAN 7 interface - it automatically negotiates an MTU of 1492 when dialing in. Make sure that in none of the above mentioned interfaces in the field MTU is a real value in it.

Check the /etc/config/network file or execute uci show network over ssh for any configured mtu:

config interface 'wan'
option proto 'pppoe'
option device 'eth0.7'
option username '[email protected]'
option password 'xxx'
option ipv6 'auto'

This change improves the performance with Applications/Services such as MS Teams, Speedtests and many other ones.

Happy surfing!

@zlatovlas
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Thank you very much for this addition.
I'd like to propose that this Gist content gets its own Repository, so suggestions and additions, as well as issues can be added in for of Issues and PRs. I think also about creating a page for a modern setup (newer OpenWRT, newer Telekom/Fiber contracts), keeping the "legacy" in a dedicated page. What do you think?

I am happy to contribute.

@Kapsville
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Kapsville commented Feb 27, 2025

I tried everything and cannot get it to work ... I already used PPPoE (Telekom DSL) with the native TP-Link Firmware and everything was fine. I might miss something.. do I have to change something in my Vigor DSL Modem? I did not touch it... Is PPPoE over OpenWRT different compared to TP-Link Firmware? Maybe someone with Draytek Vigor and ER605 can push me in the right direction.

@zlatovlas
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I tried everything and cannot get it to work ... I already used PPPoE (Telekom DSL) with the native TP-Link Firmware and everything was fine. I might miss something.. do I have to change something in my Vigor DSL Modem? I did not touch it... Is PPPoE over OpenWRT different compared to TP-Link Firmware? Maybe someone with Draytek Vigor and ER605 can push me in the right direction.

Have you tried resetting your configuration while on OpenWRT? Maybe post your configuration here and we can have a look.

@Kapsville
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Hello @ zlatovlas
I resetted the ER605 a few times now.

`root@OpenWrt:~# cat /etc/config/network

config interface 'loopback'
option device 'lo'
option proto 'static'
option ipaddr '127.0.0.1'
option netmask '255.0.0.0'

config globals 'globals'
option ula_prefix 'fd13:c758:e810::/48'
option packet_steering '1'

config device
option name 'br-lan'
option type 'bridge'
list ports 'lan2'
list ports 'lan3'
list ports 'lan4'
list ports 'lan5'

config device
option name 'lan2'
option macaddr 'A8:42:A1:8C:99:E1'

config device
option name 'lan3'
option macaddr 'A8:42:A1:8C:99:E1'

config device
option name 'lan4'
option macaddr 'A8:42:A1:8C:99:E1'

config device
option name 'lan5'
option macaddr 'A8:42:A1:8C:99:E1'

config interface 'lan'
option device 'br-lan'
option proto 'static'
option ipaddr '192.168.1.1'
option netmask '255.255.255.0'
option ip6assign '60'

config device
option name 'wan1'
option macaddr 'A8:42:A1:8c:99:e2'

config interface 'wan'
option device 'wan1.7'
option proto 'pppoe'
option username '[email protected]' (changed digits)
option password xxx - I set PW in Telekom Kundencenter (used with ER605 default FW) - tried the "Zugangsdaten PW" aswell, none is working
option ipv6 'auto'

config interface 'wan6'
option device 'wan1'
option proto 'dhcpv6'

config device
option type '8021q'
option ifname 'wan1'
option vid '7'
option name 'wan1.7'
option ipv6 '1'`

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