Home / server / Questions / 1001239
In Process
Pedro Amorim
Asked: 2020-02-01 05:52:37 +0800 CST

Basic 2 Routers configurations for noobs

  • 772

So, my goal is to have each one of my devices connected to a double-NAT simple solutions.

I've started my configuration with Router 1:

IP: 192.168.1.254
Mask: 255.255.252.0

DHCP
Ipv4: 192.168.1.10 - 192.168.1.250
Mask: 255.255.252.0
Server: 192.168.1.254
Gateway: 192.168.1.254

So far so good :D

Than, I've tried to configure the second router:

WAN Setup:
Connection Type: Static IP
IP: 192.168.1.11
Mask: 255.255.252.0
Gateway: 192.168.1.254

And now my problem:

Attempt 1

  • Connected the Router 1 LAN port to the Router 2 WAN port

  • Enable DHCP, its already configured by default (192.168.4.100 to 192.168.4.200).

  • Everything connects fine, but they act like different networks, and for example, I cannot see the printer and my shared drive at the same the (they are in different routers)

Result -> FAIL

Attempt 2

  • Connected the Router 1 LAN port to the Router 2 WAN port

  • Enable DHCP, and change the range for 192.168.2.100 to 192.168.2.200

  • Get the message: The IP address is not in the same LAN IP Address.

Result -> FAIL

Attempt 3

  • Connected the Router 1 LAN port to the Router 2 WAN port

  • Enable DHCP

  • Change LAN to 192.168.0.1

  • Get message: WAN IP address and LAN IP address cannot be in a same subnet. Please input another IP Address.

Result -> FAIL

Attempt 4

  • Connected the Router 1 LAN port to the Router 2 LAN port

  • Change LAN to 192.168.0.1

  • Change DHCP range: 192.168.0.50 to 192.168.200

  • No internet in Router 2

Result -> FAIL

Attempt 5

  • Connected the Router 1 LAN port to the Router 2 LAN port

  • Change LAN to 192.168.0.1

  • Disable DHCP on Router 2

  • Too many connections for my ISP Router

Result -> FAIL

Any sugestion? PLEASE... :)

router dhcp tp-link mask

2 Answers

  1. It looks like you are placing your R2 into the same network as your R1, and thus not seeing the expected behavior. If you want to design this to be double NAT separate R2 into another network, something like this:

                           LAN NAT 1
     WAN+-----+LAN   192.168.1.0/24  WAN+-----+
.254 <--+     +-------------------------+     |
        | R1  |.1                     .2| R2  |
        +-----+                         +-----+
                                        LAN|.1
                             LAN NAT 2     |
                             192.168.2.0/24|
                                           |
                                           v
                           Devices not leasing from ISP router


(R1)DHCPv4
Range: 192.168.1.10 - 192.168.1.250
Mask: 255.255.255.0
Local IP: 192.168.1.1
Gateway: 192.168.1.254

(R2)DHCPv4
Range: 192.168.2.10 - 192.168.2.250
WAN Connection Type: Static IP
WAN IP: 192.168.1.2
Local IP: 192.168.2.1
Mask: 255.255.255.0
Gateway: 192.168.1.254

    Not sure what your R1's WAN setup is (what is Server: 192.168.1.254, if it is also the gateway?)

    • 0

  2. The main problem is that the Router 1 subnet mask is too broad. Set it to 255.255.255.0 (not 255.255.252.0).

    • In your attempt 1, the Router 2 DHCP range is consistent with the Router 1 subnet mask. The two are on different networks because Router 2 is routing: Its NAT is working.

    • In your attempt 2, you set the Router 2 DHCP range within the Router 1 subnet. Changing the Router 1 subnet to 255.255.255.0 would allow the DHCP range you specified but you'll still have different networks.

    • In your attempts 3 and 4, you have two DHCP servers active on the same subnet and the conflicts can prevent connections altogether.

    • Your attempt 5 seems to have bridged both routers.

    I may be wrong but what I think you want is a single subnet behind at least one of your two routers, with the second router available to provide additional Ethernet jacks. If so, then do this:

    • Router 1: WAN IP = DHCP (plugs into your ISP router/modem). LAN IP = 192.168.1.1. Subnet mask 255.255.255.0. DHCP range 192.168.1.3-192.168.1.254.

    • Router 2: Some routers can be switched to "bridge mode" (which simply turns off NAT) by ticking a box or selecting a configuration option. If so, do that. You may be able to plug its WAN port into a Router 1 LAN port but if that doesn't work, run the cable to a Router 2 LAN port instead.

    If Router 2 doesn't have a "bridge mode" or "disable NAT" option, then plug LAN port to LAN port and: WAN IP = DHCP or 192.168.2.1. LAN IP = 192.168.1.2. Subnet mask 255.255.255.0. DHCP range: DISABLE DHCP (to avoid conflicts with the Router 1 DHCP), so no range. These changes should "bridge" Router 2 and allow it to function as a bridge/switch (same thing). DHCP clients connected to Router 2 will get DHCP configuration from the Router 1 DHCP server.

    • 0