Skip navigation
Cisco Learning Home > Connections > Discussions

_Communities

3453 Views 7 Replies Latest reply: Feb 10, 2011 1:45 PM by josephquinajon RSS

Currently Being Moderated

About DHCP and DNS configuration in Cisco Router

Feb 5, 2011 10:12 AM

student 143 posts since
Aug 4, 2010

Hi Guys,

 

I am having a confusion about DHCP and DNS configuration in Cisco Routers, I do know about the function of DHCP and DNS but I wanted to know that

Inorder for the Router to function as DHCP should we also enable DNS on it or we can keep the DNS Server seperate on the network?

 

 

My other question is that why do we really need to make the Router a DNS? Do we only do it when other DNS machine is not available in the network?

 

When we make the Router as a DNS ,does the request for web traffic from the LAN goes to this Router for the resolution of domain name to ip address?

 

I hope my questions are clear

  • Currently Being Moderated
    1. Feb 5, 2011 11:53 AM (in response to student)
    Re: About DHCP and DNS configuration in Cisco Router

    A router can be configured as a DHCP server that in turn has the ability to give out Domain information to its DHCP clients, but as far as I know, it cannot act as a DNS server.

     

    For instance, you can configure the domain-name domain option or the dns-server address option on a router, which basically tells the DHCP client the domain name and IP addresses of DNS servers.

     

    HTH

    DelVonte

  • Conwyn 7,907 posts since
    Sep 10, 2008
    Currently Being Moderated
    2. Feb 5, 2011 11:57 AM (in response to student)
    Re: About DHCP and DNS configuration in Cisco Router

    Hi Student

     

    DNS server on a router

     

    If you want to  implement a DNS server on the router use the commands

    ip dns server
    ip dns primary conwyn.com soa ns.conwyn.com conwyn.conwyn.com 21600 900 7776000 86400

    then the dns server uses ip host as its data to satisfy DNS requests.

     

     

    Regards Conwyn

  • Currently Being Moderated
    3. Feb 5, 2011 12:09 PM (in response to Conwyn)
    Re: About DHCP and DNS configuration in Cisco Router

    Didn't know that could be done. Thanks for that one Conwyn, learned something new today.

  • Conwyn 7,907 posts since
    Sep 10, 2008
    Currently Being Moderated
    4. Feb 5, 2011 12:36 PM (in response to DelVonte)
    Re: About DHCP and DNS configuration in Cisco Router

    Hi DelVonte

     

    It is just the Cisco Learning Network living up to its name.

     

    Regards Conwyn

  • Conwyn 7,907 posts since
    Sep 10, 2008
    Currently Being Moderated
    6. Feb 6, 2011 12:44 AM (in response to student)
    Re: About DHCP and DNS configuration in Cisco Router

    Hi Student

     

    Post two show you how to implement DNS server on a router.

     

    Regards Conwyn

  • josephquinajon 4 posts since
    Sep 11, 2010
    Currently Being Moderated
    7. Feb 10, 2011 1:45 PM (in response to student)
    Re: About DHCP and DNS configuration in Cisco Router

    hi Student,

     

    (dhcp-config)#default-router 192.168.1.254----> this is the IP address of the Router.

    dhcp-config)#dns-server 192.168.1.254-------->configuring DNS on the Router.

     

     

    On the first configuration, the router tells its dhcp clients or configures the dhcp client's default gateway to this address 192.168.1.254. So when the client have traffic outside the network or to the internet, it will send that traffic to it default gateway which is in your case 192.168.1.254.

    On the second configuration, the router tells its dhcp clients to use the IP 192.168.1.254 as its DNS if the client wanted to send traffic to the internet.

     

    The 2 lines of configurations will be sent to all dhcp clients of the same subnet of course and will be configured  automatically on the clients TCP/IP together with the IP address of the dhcp client which is from the DHCP address pool.

     

         (dhcp-config)#network192.168.1.0 255.255.255.0, -- IP address to be assigned.

     

    I hope this will help you clear your understanding to your problem.

Actions

More Like This

  • Retrieving data ...

Bookmarked By (0)