Site has a Netgear FVS336Gv3 dual WAN router.
The router firmware is up to date.
The FVS336 was put in a few weeks ago with only WAN2 connected to an ADSL modem, in anticipation of a new 10/10mbps connection being implemented down the road.
The router is working fine with the ADSL connection.
The new main Internet connection has been installed and is presented at the premises on a Network Termination Unit, or NTU, which is a fancy modem that aggregates several DSL connections into one.
We know that the NTU is working because we've connected a laptop to it configured with the static IP info provided by the ISP and we get on the net, can run speedtest.net etc & all is well.
Configured the FVS336 WAN1 connection with the static IP info and plugged the NTU into WAN1 on the FVS336. We get connection lights at both ends, but the router reads that the connection on WAN1 is down.
The cable betweeen the FVS336 and the NTU is tested & good. It's also been changed for another known-good cable.
WAN1 on the FVS336 has been independently tested and works.
We've even changed the FVS336. Same problem.
Can anyone suggest what on Earth is going on?