"DNS Server Set up" the erection and testing of a forwarding DNS server under CentOS

Pre-Erection Preparation:

To set up a DNS server, you must install a software program that provides a DNS service, the BIND software, that can be installed using the following command:

Yum install-y bind-chroot Bind-utis

1. Modify the master configuration file/etc/named.conf

This server is relatively simple to set up, that is, in fact, this [so-called DNS server] as a proxy, up to query DNS information, this environment, only need to modify/etc/named.conf this master configuration file can be modified as follows:

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After the above configuration is complete, use the following command to start the DNS service:

/etc/init.d/named start

Remember to check when the configuration is complete:

Check/var/log/messages's content message (very important!) )

Tail-n 30/var/log/messages | grep named

named It is important to check the information in the/var/log/messages if it starts successfully!

Follow the steps above to successfully set up a simple forwarding DNS server, which will be tested on this DNS server:

2. Test the availability of a forwarded DNS server

1 method One: Use the dig command to specify the DNS server address

[Email protected] ~]# dig www.google.com @127.0.0.1

After using this command:

If you find the IP of Google, and the output data at the bottom of the "server:127.0.0.1#53 (127.0.0.1)" Word, it means that it should be successful.

This is illustrated below:

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The test is successful!

2 method Two: Use the address of the DNS server built on this computer as the DNS server address

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The test is as follows:

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You can see the successful return of the IP address of the domain name, indicating the success of the test!

Forwarding the DNS server is not difficult to set up, as long as the main configuration file/etc/named.conf to modify, and modify the above configuration can be.

Advantages of forwarding DNS servers:

It is important to note that because the forwarding DNS server is the DNS request of the client to the first level DNS server set up for DNS queries, so long as the level of the set of DNS server stable and responsive, the performance of our own DNS server can also be greatly improved.

Disadvantages of forwarding DNS servers:

Because many public DNS servers are now intelligent DNS servers, such as 202.96.128.86 and 202.96.128.166 above, this means that it can be based on the type of IP address of the client (telecom, Netcom, mobile, etc.) to return the server IP list of the corresponding carrier, To allow the client to achieve the fastest access speed. So there is a problem here, that is, we set up a forwarding DNS server, regardless of the client using the forwarding DNS server to use what type of operator, these clients when querying the IP address of the domain name, the resulting IP address is the forwarding DNS server corresponding carrier type, This affects the speed at which clients that forward DNS servers access the Web site, which is not used by the same carrier as the forwarding DNS server, so pay particular attention to this issue when setting up a forwarding DNS server.

This article is from the "fragrant fluttering leaves" blog, please make sure to keep this source http://xpleaf.blog.51cto.com/9315560/1660181

"DNS Server Set up" the erection and testing of a forwarding DNS server under CentOS