Asus RT-AC87U and the router is connected to a Hitron CODA 4582U in residential gateway mode. - If the CODA is Gateway mode, then it's acting as a router. It would have an address of 192.168.100.1.
If you want to run it in bridge mode, you won't have wireless from the CODA.. You need to decide which device you want to be the router / DHCP Server in your network.
As other's have suggested, a cleanup is required. Setting the CODA to bridge mode. If I was to pick, I would use the Asus as the router. If you are using VPN's I would suggest using another network, other than 192.168.1.x, potential for, possible VPN conflict.
If you want to run it in bridge mode, you won't have wireless from the CODA.. You need to decide which device you want to be the router / DHCP Server in your network.
As other's have suggested, a cleanup is required. Setting the CODA to bridge mode. If I was to pick, I would use the Asus as the router. If you are using VPN's I would suggest using another network, other than 192.168.1.x, potential for, possible VPN conflict.