I see people genuinely helping out here but please stop with down-votes.I wouldn't have posted on server fault if this wasn't really a business problem.I am going to upgrade this network with a Failover WAN connection and separate the Home and Work Network.Server on my network serves as a local Testing Environment and database server and a NAS data backup. I do not work with servers daily but i need a solution for my problem which is not personal or anything.I said i have basic knowledge because i surely know people are working this stuff daily and there is a lot to learn.

I have this problem for some time now but i was not able solve it. Questions: connect two routers with different subnet and other comments helped a lot.

I am new to this but have some very basic knowledge to do it. Network Check the network image. There are 3 routers currently:

  • Router 1
DHCP Internet
DNS for whole network
Wif5G Band --> Wireless Repeater Router 2
Active DHCP Server: x.168.1.20 - x.168.1.120
Static Route: : Gateway
  • Router 2
Wireless Repeater Mode on Router 1 WIFI5G Band
  • Router 3
Connected to LAN 1 on Router 2 (Wireless Repeater)
Active DHCP Server: x.168.0.20 - x.168.0.200
Static Route: : Gateway :

Ubuntu Server:

Static IP

I am using the first router as a DNS server because the repeater is a repeater so no DNS and Router 3 is not as Flexible with Settings as the Router 1. So i want to handle DNS from Router 1. I need to connect to Router 3 from Router 1 which is not working but when i am connected to Router 3, Connecting to Router 1 is working.

So my Situation:

ROUTER 1 ----> ROUTER 3 and its devices XX Not Working

ROUTER 3 ----> ROUTER 1 Working

As this is not working i am also not able to connect to the server also from devices connected to Router 1. Please suggest anything that needs to be changed or added so that Router 1 Devices can access server on Router 3 and Router 3's interface.

UPDATE: The route flags for Router 1 to Router 3 are "UG" only . UPDATE 2: Router 1 is now Connected to Router 3 Directly R1 Lan3 ----> R3 WAN.With no success still not able to ping R3 or the server on it from devices on R1.

ANSWER: The R3 have some serious in built firewall which is not possible to turn off and even putting filtering rules off and opening everything have problems and do not allow connecting to R3 from a WAN connection. Only possibility could be running another R1LAN to R3LAN allowing all LAN connections and WAN for Internet. Discussion with Matthias and Ron helped and if you don't have such type of router then it should be easy to connect to with simple Static Routing. Thanks everyone who helped.

  • It looks like the ARP requests for address don't get from Router 1 to Router 3. Can you verify this by listening for ARP at the WAN interface on Router 3 with tcpdump? – Mathias Weidner Apr 15 at 12:49
  • Off topic: I am new to this but have some very basic knowledge to do it means it is off topic here. We do not provide learning material. Basic knowledge of networking is required as per site rules. As is following business best practices. And the question has to be in a business environment. As it stands, it belongs to superuser.com – TomTom Apr 15 at 12:58
  • Sorry ,TomTom I found that server fault have many questions similar to this and even after situation matching to mine I was not able to do it.I am new to this but surely a genuine problem which is related to another question on server fault. – Dushyant Deshwal Apr 15 at 13:10
  • @Mathias Weidner ok, I will try this and get back to you. – Dushyant Deshwal Apr 15 at 13:10
  • @MathiasWeidner There is no way i could find to access the data or listen to ARP request on router 3.These are consumer grade hardware and on top of that Router 3 have least things to tinker with. – Dushyant Deshwal Apr 15 at 14:30

Router 3 needs a static default route to

Router 1 needs a static route gw:

You can remove the static route on router 3.

  • Thanks Ron for the reply, I did that.With or without a static route on Router 3 the Results are same not able to go from Router 1 ---> Router 3. Router 1 have a static route through gw: – Dushyant Deshwal Apr 15 at 13:57
  • Does router 3 have a firewall enabled? – Ron Trunk Apr 15 at 14:09
  • No, there are no rules set in firewall and everything is disabled on all 3 routers. – Dushyant Deshwal Apr 15 at 14:12
  • When you say connect to router 1 What exactly, are you doing? Ping test? From where to where? – Ron Trunk Apr 15 at 14:17
  • A PC connected to Router 3 and access the IP and (The Wireless Repeater Router 2) and I get the local interface for settings and all. Also I have a DNS Entry on Router 1 with server.ubuntu which points to (Which is on Router 3). So when i am connected to router 3 i can even put that "server.ubuntu" in web browser and i am able to access the server. But same is not possible while being connected to a device on Router 1. give no result (Not found) and same for or server.ubuntu for the server. – Dushyant Deshwal Apr 15 at 14:25

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