@Clive_A I've also changed LAN IP pool from 192.168.x.x/24 on ER605 to 10.0.x.x/24 on ER8411. After close inspection on WAN (ISP) config of PPPoE connection I've got WAN Gateway IP at 10.0.x.x That...

@RaRu Thank you, I will test RaRu wrote @268BBA What do you do to restore the network connection? May I suggest you, once the WAN is down, to just simply disconnect WAN cable from TP-Link router and...

@Clive_A It went down again :( I've requested intervention from ISP to check, if it still not resolved, I will try to factory reset it and configure all network again. About that how should I do it ?...

@Clive_A With ER605 I did not have any issues, this issue starts once ER8411 was installed. Other things that I've changed in configuration on ER8411 and not have it on ER605 are: 1. I've set DST...

@MR.S Thank you !

MR.S wrote @268BBA hmmm, that was strange. I have exactly the same solution, ER8411 and SG2428P switch but have never noticed that WAN drops. Are you using L2TP VPN then? I have noticed that there...