Isn't that failover rather than load balance.
The problem I've got I want to be able to direct traffic down one wan which doesn't work.
Draytek did a remote session and are baffled at the moment. I'll give them another prod tomorrow.

I had a issue yesterday which might of been the same but could be related to something else...

I run two sub-net's , 1 for the business ( 192.168.1.1/24 ) and the other for guests ( 192.168.2.1/24 ) access thru untangle server...

however guest network wasn't allowing any internet or access to the router/gateway IP even at the time , so allowed untangle to control Vigor120 via PPPoE , so runing Vigor3900 on a single WAN which seems a bit pointless at this to buy a MultiWAN router and can't fully use it at this time, might just wait for any firmware to be released and try again

More discussions with Draytek.
The latest attempt was backing up the config and then resetting defaults and then loading the config back. This set the rules I had chosen but if I decided to change one the rule was again ignored.
upnp on the local lan is still broken as well.
Anyway they have my config for testiing.

Still no luck then...

my issue was down too untangle server ( bridge not working properly ) not due to the Draytek Vigor3900 ( 3900 is the same OS etc than 2960 )

I have two ADSL2+ lines both via Vigor120's ADSL2+ Modems PoE , both ADSL2+ lines are business static 20:1 ratio which are 2Km from exchange ( just outside the maximum length for VDSL ), is there a proper way to load balance both WAN's for LAN1 and leave LAN2 on WAN1 only and have LAN2 Capped per session / user / device ???

I've been running the 3900 for 3 weeks now and noticed about the same issues as yourself ( Pit )

1. Load balance for LAN1 that gets or I should say should get a balance load from both WAN1 and WAN2 , however LAN1 is slower to respond to website requests or sticks all together and have to press refresh or try again for that page , tho LAN2 only gets WAN1 no load balance , PDQ machine on LAN1 takes 20 seconds to complete requests via ethernet when load balance is in effect , remove load balance and only give LAN1 to WAN2, the PDQ completes the request in 5 seconds.

2. port forward for the security cameras ( 8 off ) half the cameras on WAN interface don't respond , and not the same ones when trying again , more erratic like oad balance is refusing the data to run down the specific WAN that port forward is set too

P.S. is there away in the new firmware thats still in production ( USB 3G facility etc ) to allow the load balance to specific range of IP and specific ones , my old Vigor 2820 and 2830 could , which would sort out the port forward issue

Thought I would come back to the Draytek Forums to get a feel for the new products - as I gave up on my old 2800VG when I got BeThere.

Unfortunately it's a case of same old, same old - as it still seems to be a case of waiting for a firmware upgrade to solve problems that shouldn't have been there in the first place when the product was released!

A shame, as I wanted to go back to Draytek when I get my VDSL.

Ho Hum!