Multiple Nameservers on Same IPs

I'd like to know as well. I'm kind of doing the same thing.

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Firstly, I have not done this myself. But I am just as curious to know the facts.

A major problem in this context (I think) is the issue of reverse DNS. Many country level domain registrars play it by the book and require reverse DNS to be set up for name servers. Since a PTR record has to be unique, i.e. an IP can point to one name only, I cannot see how one can reuse an IP for multiple name servers.

Looking forward to the explanations

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Hello again,

Well I'm not sure if this is going to work, but after reading a zillion posts it seems to make sense. I hope.

Basically the server has a Main ( Server ) IP and a secondary IP. I've set these up as follows of course:

ns1.mydomain.com 111.111.111.111
ns2.mydomain.com 222.222.222.222

For my reseller accounts I have created a new account with a dedicated IP for them. I then use my main server second IP for the reseller second IP. So I get this.

ns1.resellerdomain.com 333.333.333.333
ns2.resellerdomain.com 222.222.222.222 ( same IP as in mydomain.com )

I then go to "Manage Reseller Main Shared/Ipless Ip" and select "ns2.mydomain.com / 222.222.222.222" as the shared IP for the reseller accounts.

This way I keep the Main Server IP for myself and my own sites. Plus I can give each reseller their own dedicated IP. The second IP for all accounts including mine becomes the shared IP for all name based accounts.

At the moment, everything is propogating, but so far so good. I'm also not sure if this is acceptable or will work 100%, but it seems to make some sense.

I'm sure there is a better way to set these things up and preserve IPs, but since I'm kind of new at this I'll probably makes some mistakes and learn a few lessons along the way.

Any comments or suggestions are greatly appreciated.

- Jim

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Dont you have to add it as a Name Server at some point? I tried the above (adding the A-records), and it works, but DNSreport.com reports 2 missing nameservers. I dont see any problems, but is it possible for one to pop up?
If I add an A-Entry for the nameserver under Edit Reseller, would that cause any problems for the main name server?

 

Well, I came accross this several year old, never really answered article while looking for something completely irrelavent; I just thought I would spice it up a bit, seeing as this is a highly ranked article in google. Here goes...

For the last 5 years I have been using cPanel web servers, of which every server I have used has taken advantage of shared nameservers. That being said, it is in invaluable tool to help you save money and resources with additional IP addresses for every new nameserver you want to use.

Some advice on general server setup. Your host, the machine itself should have an ip assigned to it (which is also the primary pool address). This address should not be used for a shared nameserver, as your email will most definately require a proper reverse dns pointer to work correctly. That being said, if you do setup a shared nameserver on the host ip, anyone looking up your nameserver ip will see who the ip belongs too more easily. (If your a hosting company, you may not want your hosting name on resellers nameserver addresses).

Before you begin, you need to take a look at the registrar records for the domain name you are making name servers for. I don't believe anyone really mentioned that before. Example, if your domain is example.com and you bought the domain from GoDaddy.com then you need to login to GoDaddy.com, your domain registrar and add host entries for each of your nameservers. For our example we would want to add a host for NS1 and NS2 as follows...

NS1 Resolves to 10.1.1.11
NS2 Resolves to 10.1.1.12

Note: It can take 48-72 hours for this information to propogate across the entire world wide web; however, it can take only a few minutes in some cases.

Once you have done this, it is safe to proceed to WHM to setup your A records in your DNS zone. Now, the easy way to do this, is to allow WHM to create the A records for you under your Basic Setup. However, I do not like this approach as each host will also be setup with an mx record, ftp record, etc. Instead, if your setting up a nameserver for an existing website or a website you plan to host in the same server, setup the the site first and then edit the dns zone. Be sure to add one A record for each nameserver, exactly as above...

NS1 A 10.1.1.11
NS2 A 10.1.1.12

Note: It can take 48-72 hours for this information to propogate across the entire world wide web; however, it can take only a few minutes in some cases.

Save these changes! Now, if all went well and you are patient enough for to allow domain propogation to occur, you simply need to tell cpanel that nameservers will be used on those ips. If you are using the most current cpanel, this is automatic. Just click on the Nameserver Ips from the WHM menu and as soon as you go to the page it will automatically detect the primary nameserver we just setup and notify you that it is assigned to the correct ip. If you set it up correctly, you will not have to add the nameserver yourself!

Finally, before using the Reseller Center to start shelling out shared nameservers, you need to check your Tweak Settings to be sure that nameserver sharing is allowed. And after assigning nameserver names to a reseller, you will need to tell the reseller the same initial steps for setting up their nameserver through their registrar using 10.1.1.11 and 10.1.1.12 as NS1 and NS2.

As for revers dns for the shared nameservers, it is not required, but is highly recommended. However the end result may not be desired, depending on your situation. I have successfully run nameservers without reverse dns without problem, as long as the host ip is not the nameserver ip. Just remember if you share nameservers whoever you put in the reverse dns pointer is ultimately responsible!

Sorry for typos, its late, i'll review this in the am. Have a great night!