I have a Vigor 2955 with 2 WAN ports configured with traffic being balanced/routed between the 2.

WAN 1 is a static IP configured port talking to our EFM router.
WAN 2 is a PPPoE configured port connected to our BT Openreach FttC modem.

Traffic routed over the PPPoE connection experiences MASSIVE packet loss (~99%) and is obviously pretty much unusable.

If I connect a machine directly to the BT Openreach modem an establish a PPPoE connection all is well and I get a perfect connection with little packet-loss.

The logs show no error or problems, CPU and memory utilisation are acceptable etc

Can anyone help me shed any light on this issue?