Cannot receive DNS response from another LAN.

[Frank27]

The problem .

Configuration :

Router1---->LAN1(switch1)--->DNS Server

Router2---->LAN1(switch1--same switch)--->DNS Server

Considering that:

Router1 is inside the vlan 1 192.168.0.1/24 

DNS Server is inside the vlan 1 192.168.0.2/24

Router 2 is inside the vlan 1 through the same switch in the same subnet with  192.168.0.3 on interface GE 0/0

Router 2 has another subnet attached to the interface GE 0/1 with a different LAN (10.0.0.1)

Router 1 knows how to reach the other subnet through RIP and I can ping all the hosts inside the LAN 10.0.0.1 from the subnet 192.168.0.0/24 without problem and vice-versa i can ping the DNS server and Router 1 from any hosts in the subnet 10.0.0.0/24

Router1 ip name server is the local DNS server with 192.168.0.2

Router 1 correctly exit out from that server translating any address and pinging any external (www.google.com)

Router 2 , from the interface GE0/0 with the IP in the same subnet and with the name-server of the router1 or the DNS server IP (tried both) can ping correctly when i type:

ping www.google.com source interface gigabitethernet0/0 

but when i ping www.google.com from interface gigabit0/1 there is no response.

I also tried to add a default route to Router1 in router2  but from the second LAN (10.0.0.1) interface I cannot receive any answer from the ICMP when pinging google.

That's look weird to me since all hosts can ping each other?

Anyone have idea why?

[Laith9Sky]

dear sir,

if this lab is locally configured in packet tracer it means that you have no access to the internet and you can only reach your dns with your local IP.

[Frank27]

no this is a real network, no packet tracer.

[Frank27]

the only thing that could come to my mind is to enable NAT on router 2..

but why I should enable NAT if the subnet 10.0.0.0 is perfectly reachble from Router 1 and even from the DNS server I can ping all hosts (and even connect) to the network 10.0.0.0 connected to router 2 gb0/1 ? Note that the gb 0/1 is not connected (of course) to the same switch of router 1.

[Georg Pauwen]

Hello,

post the full running configs of both routers...

[Jon Marshall]

It sounds like NAT has been setup for 192.168.0.x IPs but not the 10.0.0.x IPs. 

What is device is doing the NAT ? 

Jon

[Deepak Kumar]

Can you share DNS configuration and out of a few commands such as "sho ip dns view" and "sho ip dns view-list"? 

[Frank27 · Accepted solution]

Yes the problem was for the NAT which was not configured yet.

Thanks!