-1

I just bought a VPS with cPanel/WHM. My hosting provider gave me 3 dedicated IP addresses with my plan. I read on the internet that I should use 2 IPs for my nameservers and the other one as the main IP for all my shared accounts.

Could you tell me why I should do that ? What are the advantages of using IP addresses only for nameservers and another one only for my shared accounts instead of using the same IP for all my nameservers and shared account ? I'm asking because I don't want to use an IP for nothing.

Thank you.

HopelessN00b
  • 53,385
  • 32
  • 133
  • 208
Marc-Antoine
  • 41
  • 1
  • 5
  • 2
    Using two IP addresses to point to the same name server would not be a good idea at all. Completely defeats the point of having more than one defined in the first place. – gparent Apr 26 '13 at 19:07
  • 2
    The advice regarding name servers is that there should be at least 2 different machines not just 2 different addresses. Like I said earlier, use your registrar's name servers it will be so much easier for you with your current level of understanding. – user9517 Apr 26 '13 at 19:07
  • 1
    @Marc-Antoine: NS1 and NS2 should be different machines not just different IP addresses. – user9517 Apr 26 '13 at 19:17
  • Administration panels are off-topic on Server Fault. – HopelessN00b Feb 22 '15 at 01:40

2 Answers2

4

The reason you should use 2 IP addresses for your nameservers is that DNS Best Practices and RFCs dictate this as a requirement.

The point isn't literally "just because you need 2 IP addresses" but the point is for redundancy purposes. So the real requirement (for DNS best practices) is 2 different DNS servers, so that if 1 server fails, your domain name(s) still resolve on the second DNS server.

That said, it is very possible (but again, not recommended) to use two different IP addresses on the same server to respond to DNS queries.

Other than that, there's no real advantage to using the same IP address for multiple services (i.e. you can run Apache, BIND and Postfix, for example, all off the same IP address).

David W
  • 3,405
  • 5
  • 34
  • 61
  • did you mean ... no real disadvantage ... ? – user9517 Apr 26 '13 at 19:03
  • 1
    Hah. I guess it could be said either way. I meant advantage, but I see how it would make sense to say "disadvantage" there too! – David W Apr 26 '13 at 19:05
  • As I mentioned, you can use the same IP address for different services (DNS / BIND, Apache, Exim / Postfix, etc...). There's no real advantage or disadvantage to using the same IP address for different services. Well, I guess some people could argue for spam / blacklisting reasons, but mostly that's just getting into semantics and doesn't really count as a valid reason. – David W Apr 26 '13 at 19:16
  • Last comment.... sometimes you want multiple IP addresses so that you can run multiple websites behind SSL (HTTPS) connections. (A SSL certificate requires a dedicated IP address). – David W Apr 26 '13 at 19:26
  • I know that.. but if I use the same IP for my nameservers and shared accounts.. I think rDNS is impossible. That could be a disavantage ? – Marc-Antoine Apr 26 '13 at 19:52
  • @Marc-Antoine You should listen to the guys, they know about stuff: do not run DNS on your virtual servers, let the hoster handle that for you. Use the IP addresses for anything you need them for - SSL, game servers, web services, ... - just ***not DNS***. – the-wabbit Apr 26 '13 at 20:26
  • 1
    You don't create NS1 and NS2 or the corresponding Glue Records because your host is already doing it. Don't mess with DNS at all. Also, just a note: Comments shouldn't really be used for asking new questions. If you have related, but different questions, please ask a new question instead. This will be my last comment / answer on this thread. – David W Apr 26 '13 at 20:43
0

Maybe my question wasn't precise enough. I wanted to know how to configure nameservers with cPanel on a VPS without loosing the redundancy of the DNS. I though it has to do with IPs... but it's not. The problem is cPanel and nothing else :

A standard server with cPanel/WHM is providing simultaneously all these services: DNS, HTTP, FTP, Email, etc. However, for redundancy reasons, we usually have independent replicated DNS servers for each nameserver. Since we only have one DNS server into the main cPanel/WHM server (because some features in cPanel needs to control DNS Zones) we have to point all our nameservers there. We then loose the redundancy, even if we have more than one nameserver because we only have one DNS.

Still, there are two solutions to overcome this problem. The first solution is to buy a VPS server with “cPanel DNS Only” installed on it. After, we have to activate the DNS clustering feature on our cPanel/WHM main server to “clusterize” our DNS Zones to these VPS. This way the main server and cPanel are still controlling the DNS Zones and we have now the redundancy we wanted. The second solution is to use a third party DNS solution. However, many features of cPanel will not work correctly (subdomain creation, domain addon, zone editing, etc). We will need to manually ajust the DNS Zones with the third party DNS system.

Marc-Antoine
  • 41
  • 1
  • 5