How to connect 2 router LAN's together

dsmcphee1 · ‎09-11-2005

I have an ADSL router connected to an ISP. It's LAN address is 10.1.0.1.

Connected to this router is another router (A VPN router). It's WAN address is 10.1.0.2. And it's LAN address is 10.1.1.1.

However, I am unable to ping anything on the first router (ADSL router) from the VPN router. Such as a PC's with IP's 10.1.0.x. Nor can I access anything on the Internet from the VPN router (I can from the ADSL router). I know that each router can see each other because I can A) Access the remote management screen of the VPN router via it's WAN IP of 10.1.0.2 from the ADSL router. And B) The VPN router will pick up a WAN address with no problem if I were to set it to auto get (as an example).

Can somebody please tell be the correct IP settings required on both routers in order for data to pass around OK. Internet from either. Router to router etc.

Ultimately, I am just trying to connect 2 LAN's together and be able to communicate between both LAN's and out to the Internet.

mehrdad · ‎09-11-2005

as i understood you connected ADSL router and VPN router as below:

LAN2-----[VPN ROUTER]-----LAN1-----[ADSL ROUTER]-----[ISP]

you can't ping ADSL router (10.1.0.1) because it doesn't know about the network 10.1.1.x so to solve this issue your should define a static route at ADSL router like :

ip route 10.1.1.0 255.255.255.0 10.1.0.2

(depending on your adsl modem brand)

now you can ping adsl router from vpn router.

if you're going to access network 10.1.1.x to internet then you should nat that network by ADSL router also you must add default gatway of vpn router to adsl router, configure Default gateway of each PCs on LAN2 to 10.1.1.1 as well.

if default gateway of each of PCs on LAN1 (10.1.0.x) configure to 10.1.0.1 or 10.1.0.2 then you can ping them from vpn router or LAN2.

dsmcphee1 · ‎09-12-2005

Hi,

Thanks for helping me out here. Really appreciate it.

The configuration in your notes is correct as follows:-

LAN2-----[VPN ROUTER]-----LAN1-----[ADSL ROUTER]-----[ISP]

I realised today that I had a TCP/IP printer connected the ASDL router with an IP of 10.1.0.2. The same address as the WAN port of the VPN router. Doh!! Rectified this straight away.

Ok, things are now configured as follows:-

ADSL Router (LAN1) IP address 10.1.0.1

WAN: As per ISP provided

Static route created as follows:-

Destination: 10.1.1.0

Gateway: 10.1.0.2

Subnet 255.255.255.0

VPN Router (LAN2) IP address 10.1.1.1

WAN: 10.1.0.2

Gateway: 10.1.0.1

DNS: ISP DNS servers

With this configuration I am able to do the following:-

Ping devices on LAN1 from LAN2

Ping web sites from LAN2

However, I cannot ping anything (except for 10.1.0.2) from LAN1 (ADSL router) to LAN2 (VPN router). I thought maybe the firewall on LAN2 was causing the problem, so I disabled it. Still no joy though. I guess I must be missing something here.

mehrdad · ‎09-12-2005

if you have a pc on lan1, please configure its tcp/ip as below :

ip : 10.1.0.5/24 or any free ip address

gw : 10.1.0.2

then ping a pc at LAN2 from LAN1(be sure that the default gateway of that pc at LAN2 is set to 10.1.1.1, if there is any active firewall on that pc please inactive it for test as well)