swex:

The same for me on TP-Link Archer C6U v1. nothing useful in logs:

Sat Jul 3 00:29:18 2021 daemon.notice pppd[4170]: pppd 2.4.8 started by root, uid 0
Sat Jul 3 00:29:18 2021 daemon.debug pppd[4170]: Send PPPOE Discovery V1T1 PADI session 0x0 length 12
Sat Jul 3 00:29:18 2021 daemon.debug pppd[4170]: dst ff:ff:ff:ff:ff:ff src MASKED
Sat Jul 3 00:29:18 2021 daemon.debug pppd[4170]: [service-name] [host-uniq 4a 10 00 00]
Sat Jul 3 00:29:23 2021 daemon.debug pppd[4170]: Send PPPOE Discovery V1T1 PADI session 0x0 length 12
Sat Jul 3 00:29:23 2021 daemon.debug pppd[4170]: dst ff:ff:ff:ff:ff:ff src MASKED
Sat Jul 3 00:29:23 2021 daemon.debug pppd[4170]: [service-name] [host-uniq 4a 10 00 00]
Sat Jul 3 00:29:28 2021 daemon.debug pppd[4170]: Send PPPOE Discovery V1T1 PADI session 0x0 length 12
Sat Jul 3 00:29:28 2021 daemon.debug pppd[4170]: dst ff:ff:ff:ff:ff:ff src MASKED
Sat Jul 3 00:29:28 2021 daemon.debug pppd[4170]: [service-name] [host-uniq 4a 10 00 00]
Sat Jul 3 00:29:33 2021 daemon.warn pppd[4170]: Timeout waiting for PADO packets

swex:

btw in my case WAN port is working OK. Setting it to static IP make reliable connection between my desktop and OpenWRT router

darkblaze69:

Well, I found out that openwrt 21.02 cannot autonegotiate with my provider's cable for pppoe. It shows 'no link', speed unknown etc.
# ethtool wan
Settings for wan:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised pause frame use: Symmetric Receive-only
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Speed: Unknown!
Duplex: Unknown! (255)
Port: MII
PHYAD: 1
Transceiver: external
Auto-negotiation: on
Supports Wake-on: d
Wake-on: d
Link detected: no


When I switch off autonegotiation and forced to 100baseT/Full, pppoe worked like a charm.
So as a workaround I added to /etc/rc.local:
/usr/sbin/ethtool -s wan speed 100 duplex full autoneg off

darkblaze69:

So I created new bug https://bugs.openwrt.org/index.php?do=details&task_id=3932&order=dateopened&sort=desc

thiagokokada:

I had similar issues as Alexey Mednyy, but at least in my case forcing the MTU to 1492 on the pppoe-wan interface seems to fix the issue.

swex:

wow, sad there is no notifications for this forum. I also found a way to fix it with ethtool, but in my case device shows me solid 1000mbit connections (there was no It shows 'no link', speed unknown etc. as in darkblaze69 case)
so I used

ethtool -s wan speed 100 duplex full autoneg on

in my case if I set 'autoneg off' interface is not able to determine its link state...