[FS#1159] SLAAC Only function on WAN interface if WAN is bridged

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - DirkS (dersch81) 

Attached to Project - LEDE Project
Summary - SLAAC Only function on WAN interface if WAN is bridged
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Low
Priority - Very Low
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details - TP-Link TL-WDR3600 v1


  * LEDE Reboot 17.01.4 r3560-79f57e422d / LuCI lede-17.01 branch (git-17.290.79498-d3f0685)

  * mwan3	2.0.2-1

case: If an WAN interface is bridged to a WLAN and additional WANv6 interface is requesting the IPv6 address which is only available wie radvd and not DHCPv6 the WANv6 interface goes down as follows:

daemon.err odhcp6c[18280]: Failed to send DHCPV6 message to ff02::1:2 (Permission denied)
daemon.notice netifd: Interface 'wan2_6' is now down

This only happens if the WAN is bridged. If you take away the bridge everything works well. 

Usecase where it happened and how to reproduce:

The LEDE Router has a WAN Uplink after another Router and is double NATted. In addition there is WAN2 with Freifunk Client uplink. Since the local Freifunk community provides IPv6 via SLAAC only there is an WAN2_6 Interface, too. To deal with both Uplinks MWAN3 is installed as loadbalancer. 
WAN2_6 get's its IPv6 adress and it works well. 
But in addition to the local available Freifunk Network there should be a WLAN with Freifunk client network. Therefore the WLAN is bridged to WAN2 which is the Freifunk Client network. And if this happens WAN2_6 does not work anymore. The DHCPv6 request is denied. The local Freifunk IPv6 is provided via radvd and there is no problem to receive via SLAAC only the address. If the bridge option is away of WAN2, then the WAN2_6 interface get it's IPv6 again. 

   

 

One or more files have been attached.

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=1159