[RT-AC87U]: question on my set-up

[GSpock]

Hello,
I am running Merlin 378.53.
My router is connected to my ISP BOX via its WAN port.
My router is doing a PPoE connection via the ISP BOX and gets its public ip.
My ISP BOX is also doing a PPoE connection and gets its public ip.
(note that my ISP allows up-to 2 different public IP on one line).
My ISP BOX has 192.198.99.1 as internal IP address and provide dhcp to its wifi/cable clients.
My router has 192.168.1.1 as IP address and provides dhcp to its wifi/cable clients.
I noticed my router gets 192.168.99.5 as IP address from my ISP BOX.

Before RT-AC87U, I had a netgear router running tomato and from a 192.168.1.x I was not able to access any 192.168.99.x client, which is the behaviour I was expecting.

Now, with the new AC87U, from any connected 192.168.1.x client I can access any 192.168.99.x client and vice-versa.

I would like to understand how it is possible and which parameter on my router allows that access.
Thanks,
GS

 

[hardtotell]

Hello,
I am running Merlin 378.53.
My router is connected to my ISP BOX via its WAN port.
My router is doing a PPoE connection via the ISP BOX and gets its public ip.
My ISP BOX is also doing a PPoE connection and gets its public ip.
(note that my ISP allows up-to 2 different public IP on one line).
My ISP BOX has 192.198.99.1 as internal IP address and provide dhcp to its wifi/cable clients.
My router has 192.168.1.1 as IP address and provides dhcp to its wifi/cable clients.
I noticed my router gets 192.168.99.5 as IP address from my ISP BOX.

Before RT-AC87U, I had a netgear router running tomato and from a 192.168.1.x I was not able to access any 192.168.99.x client, which is the behaviour I was expecting.

Now, with the new AC87U, from any connected 192.168.1.x client I can access any 192.168.99.x client and vice-versa.

I would like to understand how it is possible and which parameter on my router allows that access.
Thanks,
GS

What is the Subnet mask for the LAN?
What is the Gateway address for LAN?

I don't use PPoE, but maybe your ISP is somehow assigning a Subnet mask of 255.0.0.0 which would put all your devices on the same network?

 

[GSpock]

subnet mask is 255.255.255.0 both on the ISP BOX and the router.
the gateway for the LAN is 192.168.99.1 on the ISP BOX and 192.168.1.1 on the router ....
Thanks.

 

[Nullity]

Why not put the ISP BOX in bridge-mode?

 

[GSpock]

Thanks for your answers.
Because ISP does not allow full control of this device, and I am not even sure this parameter is available. Note that I still want to keep the 2 PPPoE connections so that I get 2 different public ip (for reason that I will not detail here) ....would this still be the case if ISP BOX is in bridge mode ?

The point is that I really would like to understand what is different with the asus router compared to the (old) netgear one ....