PPPoE: "unknown error (USER_REQUEST)" - DSA misconfigured?

Dermac · July 11, 2025, 6:37am

Hi,

I am trying to connect my Zyxel T-56 (which is a branded EX5601-T1) to my ISP, Maingau (1&1 reseller to the best of my knowledge), Germany.
According to the ISP this is straightforward: PPPoE credentials and VLAN 7, but I have been unlucky the last few days

root@OpenWrt:/etc/config# cat 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 'fdb5:c119:8edf::/48'

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'eth0'
	list ports 'lan1'
	list ports 'lan2'
	list ports 'lan3'
	list ports 'lan4'
	option vlan_filtering '1'

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 interface 'wan'
	option device 'eth0.7'
	option proto 'pppoe'
	option username 'myuser@megtk.int'
	option password 'mypassword'
	option ipv6 'auto'

config interface 'wan6'
	option device 'eth0.7'
	option proto 'pppoe'
	option username 'myuser@megtk.int'
	option password 'mypassword'
	option ipv6 'auto'

Log:

root@OpenWrt:~# tail -f /tmp/system.log
Mon Sep 23 14:06:09 2024 daemon.warn odhcpd[1716]: No default route present, overriding ra_lifetime!
Mon Sep 23 14:06:23 2024 daemon.warn pppd[29970]: Timeout waiting for PADO packets
Mon Sep 23 14:06:23 2024 daemon.err pppd[29970]: Unable to complete PPPoE Discovery
Mon Sep 23 14:06:23 2024 daemon.info pppd[29970]: Exit.
Mon Sep 23 14:06:23 2024 daemon.notice netifd: Interface 'wan' is now down
Mon Sep 23 14:06:23 2024 daemon.notice netifd: Interface 'wan' is setting up now
Mon Sep 23 14:06:23 2024 daemon.info pppd[30075]: Plugin pppoe.so loaded.
Mon Sep 23 14:06:23 2024 daemon.info pppd[30075]: PPPoE plugin from pppd 2.4.9
Mon Sep 23 14:06:23 2024 daemon.notice pppd[30075]: pppd 2.4.9 started by root, uid 0
Mon Sep 23 14:06:24 2024 daemon.warn odhcpd[1716]: No default route present, overriding ra_lifetime!
Mon Sep 23 14:06:38 2024 daemon.warn pppd[30075]: Timeout waiting for PADO packets
Mon Sep 23 14:06:38 2024 daemon.err pppd[30075]: Unable to complete PPPoE Discovery
Mon Sep 23 14:06:38 2024 daemon.info pppd[30075]: Exit.
Mon Sep 23 14:06:38 2024 daemon.notice netifd: Interface 'wan' is now down
Mon Sep 23 14:06:38 2024 daemon.notice netifd: Interface 'wan' is setting up now
Mon Sep 23 14:06:38 2024 daemon.info pppd[30180]: Plugin pppoe.so loaded.
Mon Sep 23 14:06:38 2024 daemon.info pppd[30180]: PPPoE plugin from pppd 2.4.9
Mon Sep 23 14:06:38 2024 daemon.notice pppd[30180]: pppd 2.4.9 started by root, uid 0
Mon Sep 23 14:06:39 2024 daemon.warn odhcpd[1716]: No default route present, overriding ra_lifetime!
Mon Sep 23 14:06:54 2024 daemon.warn pppd[30180]: Timeout waiting for PADO packets
Mon Sep 23 14:06:54 2024 daemon.err pppd[30180]: Unable to complete PPPoE Discovery
Mon Sep 23 14:06:54 2024 daemon.info pppd[30180]: Exit.
Mon Sep 23 14:06:54 2024 daemon.notice netifd: Interface 'wan' is now down
Mon Sep 23 14:06:54 2024 daemon.notice netifd: Interface 'wan' is setting up now
Mon Sep 23 14:06:54 2024 daemon.info pppd[30284]: Plugin pppoe.so loaded.
Mon Sep 23 14:06:54 2024 daemon.info pppd[30284]: PPPoE plugin from pppd 2.4.9
Mon Sep 23 14:06:54 2024 daemon.notice pppd[30284]: pppd 2.4.9 started by root, uid 0
Mon Sep 23 14:06:55 2024 daemon.warn odhcpd[1716]: No default route present, overriding ra_lifetime!

(I got rid of the ra_lifetime error by deactivating ipv6)

Verbose log:

Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  ab 36 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  ab 36 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  ab 36 00 00]
Timeout waiting for PADO packets
Unable to complete PPPoE Discovery
Plugin pppoe.so loaded.
PPPoE plugin from pppd 2.4.9
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  13 37 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  13 37 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  13 37 00 00]
Timeout waiting for PADO packets
Unable to complete PPPoE Discovery
Plugin pppoe.so loaded.
PPPoE plugin from pppd 2.4.9
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  7b 37 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  7b 37 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  7b 37 00 00]
Timeout waiting for PADO packets
Unable to complete PPPoE Discovery
Plugin pppoe.so loaded.
PPPoE plugin from pppd 2.4.9
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  e3 37 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  e3 37 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  e3 37 00 00]
Timeout waiting for PADO packets
Unable to complete PPPoE Discovery
Plugin pppoe.so loaded.
PPPoE plugin from pppd 2.4.9
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  4b 38 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  4b 38 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  4b 38 00 00]
Timeout waiting for PADO packets
Unable to complete PPPoE Discovery
Plugin pppoe.so loaded.
PPPoE plugin from pppd 2.4.9
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  b3 38 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  b3 38 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  b3 38 00 00]
Timeout waiting for PADO packets
Unable to complete PPPoE Discovery
Plugin pppoe.so loaded.
PPPoE plugin from pppd 2.4.9
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  1b 39 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  1b 39 00 00]
Send PPPOE Discovery V1T1 PADI session 0x0 length 12
 dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
 [service-name] [host-uniq  1b 39 00 00]

It seems like my ISP isn't answering at all, leading me to believe I need to configure DSA differently, but everytime I try to tag the wan-ports my laptop loses connection to the router.
These are the settings I think I need to use but that lead me to losing access to the router (THANKS devs for the automatic rollback!!!)

If anybody has an idea, please let me know!

MisterW · July 11, 2025, 6:50am

That is wrong! The wan6 interface should be dhcpv6 and the device should be the native IPv4 connection i.e @wan
In fact with 'option ipv6 auto' on the wan interface , you should not have the wan6 interface at all, a virtual wan_6 interface will automatically be created see https://openwrt.org/docs/guide-user/network/ipv6/configuration

lleachii · July 11, 2025, 6:59am

To be specific: https://openwrt.org/docs/guide-user/network/ipv6/configuration#ppp-based_protocols_and_option_ipv6

Dermac · July 11, 2025, 7:09am

Thank you so much! So basically this?

[...]

config interface 'wan'
	option device 'eth0.7'
	option proto 'pppoe'
	option username 'myuser@megtk.int'
	option password 'mypassword'
	option ipv6 1

config interface 'wan6'
	option device '@wan'
    option proto  dhcpv6

Will test this asap, but I don't live at the place yet.

lleachii · July 11, 2025, 7:20am

Remove:

The Wiki says that option ipv6 1 does the following:

Spawn a virtual interface wan_6 (note the underscore) and start DHCPv6 client odhcp6c to manage prefix assignment.

On your device, a wan_6 should automatically appear.

mk24 · July 11, 2025, 7:51am

Take eth0 out of br-lan.

Or, make two bridge-vlans so that wan and lan both exist inside br-lan with different VLAN numbers. Wan's number must be 7; lan can be any other number (conventionally 1) since it won't be sent outside the router.

But you can't have the same port both inside and outside a bridge like you are trying now.

Timeout waiting for PADO means that there is no link to the ISP at all. This happens long before IPv6 could be an issue.

moeller0 · July 11, 2025, 8:11am

+1, this is both a very common PPPoE issue and a rather unspecific one, with causes literally ranging from ethernet cable not plugged-in over wrong VLAN to PPPoE server down and a lot of things in between...

Dermac · July 11, 2025, 10:49am

This is what I have in my network now. Unfortunately it still doesn't work.

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 'fdb5:c119:8edf::/48'

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'lan1'
	list ports 'lan2'
	list ports 'lan3'
	list ports 'lan4'

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 interface 'wan'
	option device 'eth0.7'
	option proto 'pppoe'
	option username 'myuser'
	option password 'mypass'
	option ipv6 1
	option keepalive '10 10'
	option pppd_options 'debug'

The log is the same

Mon Sep 23 16:06:30 2024 daemon.notice netifd: Interface 'wan6' is now down
Mon Sep 23 16:06:30 2024 daemon.notice netifd: Interface 'wan6' is setting up now
Mon Sep 23 16:06:30 2024 daemon.info pppd[18852]: Plugin pppoe.so loaded.
Mon Sep 23 16:06:30 2024 daemon.info pppd[18852]: PPPoE plugin from pppd 2.4.9
Mon Sep 23 16:06:30 2024 daemon.notice pppd[18852]: pppd 2.4.9 started by root, uid 0
Mon Sep 23 16:06:30 2024 daemon.debug pppd[18852]: Send PPPOE Discovery V1T1 PADI session 0x0 length 12
Mon Sep 23 16:06:30 2024 daemon.debug pppd[18852]:  dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
Mon Sep 23 16:06:30 2024 daemon.debug pppd[18852]:  [service-name] [host-uniq  a4 49 00 00]
Mon Sep 23 16:06:34 2024 daemon.debug pppd[18831]: Send PPPOE Discovery V1T1 PADI session 0x0 length 12
Mon Sep 23 16:06:34 2024 daemon.debug pppd[18831]:  dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
Mon Sep 23 16:06:34 2024 daemon.debug pppd[18831]:  [service-name] [host-uniq  8f 49 00 00]
Mon Sep 23 16:06:35 2024 daemon.debug pppd[18852]: Send PPPOE Discovery V1T1 PADI session 0x0 length 12
Mon Sep 23 16:06:35 2024 daemon.debug pppd[18852]:  dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
Mon Sep 23 16:06:35 2024 daemon.debug pppd[18852]:  [service-name] [host-uniq  a4 49 00 00]
Mon Sep 23 16:06:39 2024 daemon.debug pppd[18831]: Send PPPOE Discovery V1T1 PADI session 0x0 length 12
Mon Sep 23 16:06:39 2024 daemon.debug pppd[18831]:  dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
Mon Sep 23 16:06:39 2024 daemon.debug pppd[18831]:  [service-name] [host-uniq  8f 49 00 00]
Mon Sep 23 16:06:40 2024 daemon.debug pppd[18852]: Send PPPOE Discovery V1T1 PADI session 0x0 length 12
Mon Sep 23 16:06:40 2024 daemon.debug pppd[18852]:  dst ff:ff:ff:ff:ff:ff  src f8:0d:a9:16:97:b9
Mon Sep 23 16:06:40 2024 daemon.debug pppd[18852]:  [service-name] [host-uniq  a4 49 00 00]

I also talked to a technician of my isp. On his end everything is correct. He also confirmed, that VLAN 7 is correct and that I am using the right credentials.

But he told me PADO packets are only for fibre, but my connection is VDSL. Is that something I should look into?

moeller0 · July 11, 2025, 10:57am

PADO packets are part of PPPoE negotionation, so if they use PPPoE on VDSL they will also, by necessity, need to send PADO as response to PADI packets. Maybe thy use DHCP for VDSL?

Dermac · July 11, 2025, 11:37am

Can I test that somehow?

According to their "third party router"-doc (they are using a fritzbox):

Activate ipv6 support
Activate "native ipv4"
Activate "DHCPv6 Rapid Commit"
Use username and password
VLAN 7
Pbit=0

I am trying to find a Fritzbox to see if it's something with my config or the connection itself.

moeller0 · July 11, 2025, 11:48am

Thanks for the link to the documentation, this looks like they are using PPPoE for IPv4 and IPv6 will only work within that PPPoE-tunnel as well, so we will need to figure out why the PPPoE negotiation goes nowhere...

MisterW · July 11, 2025, 7:43pm

So where is your VDSL modem ?

Dermac · July 12, 2025, 8:55am

I just realized that the VDSL modem in my router might simply not be supported...

"This page describes how to connect to networks of different commercial Internet service providers. At this time, most of the DSL configurations described below only apply to modem -router devices using Lantiq SoC. There is no DSL support for Broadcom devices.
https://openwrt.org/docs/guide-user/network/wan/isp-configurations#edpnet_vdsl"

Will need to find my old fritzbox then....

MisterW · July 12, 2025, 9:10am

Its more basic than that I think. The T56 doesnt have a VDSL modem!.
It MAY be possible to configure the Fritzbox in modem only (bridge) mode, and then connect your T56 via that. What model is it ?

moeller0 · July 12, 2025, 9:48am

But it looks like you connected your router via ethernet to something speaking ethernet as well. I had assumed you had plugged in that router to the ethernet LAN port of your DSL modem?

system · August 4, 2025, 6:18pm

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