PPPoE Problem with obtaining DNS from ISP

[Abdullah Net]

Hey everyone,

Yesterday i replaced my linksys router ,which i used just for PPPoE authentication with my ISP, with Cisco 1841 Router.

This is my home network design...

         [(1841)]------------------>(3560G-POE)-------------------->(PC)

On 1841 Router:

interface FastEthernet 0/0

description ISP PPPOE CONNECTION

no ip address

pppoe enable

pppoe-client dial-pool-number 1

no shut

interface FastEthernet 0/1

description LAN NETWORK

ip address 192.168.1.1 255.255.255.0

ip nat inside

no shut

interface Dialer1

ip address negotiated

ip mtu 1492

ip nat outside

encapsulation ppp

dialer pool 1

ppp ipcp dns request

ppp authentication pap callin

ppp pap sent-username 90115871 password 57816

no shut

access-list 1 any any

ip nat inside sourse list 1 interface dialer1 overload

ip route 0.0.0.0 0.0.0.0 dialer 1

**  when i enter "Show ip int br" command, i see that my dialer interface  got an ip address dynamically from my ISP and i can ping 4.2.2.2  successfully.

On 3560G Router:

interface vlan 1

description CONNECTION TO 1841

ip address 192.168.1.2 255.255.255.0

no shut

ip dhcp excluded-address 192.168.1.1 192.168.1.5

ip dhcp pool RANGE1

network 192.168.1.0 255.255.255.0

dns-server 192.168.1.1

default-router 192.168.1.2

import all

**  Now when i go to my PC (which is plugged to a vlan1 port), i can ping  4.2.2.2 and i can even ping google ip address but i can not browse  because i get an error saying that my dns is not correctly configured.  So, I know i am missing something in my configurations but i dont know  what is it? I really need your help

Thanks in advance...

[Jon Marshall]

Is 192.168.1.1 actually a DNS server in your network because that is what you are handing out to the client ?

If it is a DNS server is it configured to query your ISP DNS servers.

If it isn't a DNS server then you need to hand the correct DNS server IP address to the client in your DHCP scope.

Jon

[Abdullah Net]

Jon,

No i don't think 192.168.1.1 is a DNS server because i didn't do any config of that kind. How can i make it a DNS server?

Abdul,

[Jon Marshall]

Abdul

You don't need to. You just need to find out the DNS server IP of your ISP and then use that in your DHCP scope.

Jon

[Abdullah Net]

Jon,

I thought about your solution before but the problem is that my ISP tends to change their DNS server frequently, i dont know why they do that but it happens. Besides, I have 12 vlans configured each with its own DHCP scope and i find it annoying to just go under each scope and change the dns server each time the server ip address get changed.

Abdul,

[Jon Marshall]

Abdul

If you have a Micrsoft server in your LAN then you can use this as your DNS server and then have it forward on unknown queries to the your ISP DNS servers. But you still have the issue of the ISP chaging their DNS server IPs. They shouldn't really be doing this that often. If they are you may want to consider a different ISP.

Jon