My company recently purchased a DrayTek Vigor 2920n to replace an ancient Linksys router that connects to the office DSL service (AT&T). As it's a DSL service from AT&T, the router WAN connection is configured for PPPoE with an MTU of 1492. I've disabled all features in the router except for DHCP and a few NAT port redirections to servers on the internal LAN. Everything on the LAN side runs great, but I'm getting 20%+ packet loss over the WAN interface when sending PINGs to remote addresses. The old Linksys BEFSR41 that we're attempting to replace has 0 packet loss over the WAN.
The DSL modem we have from AT&T is a SpeedStream 5360 (060-5360-002), if that matters.
I'm no networking expert, but I think the configuration is pretty sound here. Is there something obvious that I'm missing that could be the source of the packet loss over the WAN interface? Does anyone know what to look for to attempt to diagnose the issue?
Thanks in advance.