I am using an Openwrt/LEDE modem/router I am happy with (Buffalo).
However, as I am transitioning from ADSL2+ to VDSL2, the Buffalo cannot deal with the DSL signal since it's ADSL only. The ISP is giving me another modem-router (ChinaWare) that works with VDSL, but it's got crippled firmware, so it can't do everything my Buffalo's doing right now.
For this reason, I'm going to use the new modem-router (ChinaWare) in modem only mode, and my old modem-router (Buffalo) in router only mode. However, the ChinaWare admin menus have no "bridge mode" option, and the Buffalo has no WAN port. Therefore, I thought that I would simply point the Buffalo's wan (pppoe) to the ChinaWare's LAN address. This, I hope, will make the router part of the ChinaWare inactive.
Here are the questions:
Suppose my "true" router - the Buffalo - has LAN IP addr 192.168.1.254.
1) Can the ChinaWare, used as modem only, be on something like 192.168.1.253, or will this wreak havoc with the rest of the LAN (computers, printers, NAS units etc.)? The alternative of setting up a dedicated VLAN and losing a LAN port on the Buffalo is much less desirable for me.
2) How do I make sure the ChinaWare never tries to hook up its WAN side (through the DSL line) to the LAN side except by opening the pppoe session? I thought about turning off NAT, firewall and all similar router options. Is there more I haven't considered? (It would be nice to have a "bridge only mode" option, but it isn't there. Talk about crippled.) If I manage to put the ChinaWare modem on the same LAN, I could even use it as another AP/ethernet switch, as long as it refers to the appropriate gateway (Buffalo on 192.168.1.254) for all WAN traffic.
Thanks for any help. I'll be glad to study any relevant material you might offer!