Secondary nameserver on different IP

[timter51]

I currently have a VPS running WHM + cPanel, it's fairly new to me doing it this way so I'm learning as I go. My VPS has it's own DNS management, so for domains I'm hosting on there I'm setting the nameserver as so:

ns1.myserver.co.uk
ns2.myserver.co.uk

Both of these nameserver addresses use the same IP address (obviously my server's IP address). I've been told that this isn't ideal, and that I should have ns2 on a different IP address / server to give better redundancy. Particularly with inbound emails which will be bounced if my server's DNS goes down, rather than queued if I had a backup secondary nameserver. If I'm talking utter bollocks here, please correct me.

I don't know where to start to sort out a secondary nameserver address that isn't hosted on my VPS. Happy to pay for reliability. Do any of you guys do this for your servers and websites? Any recommendations?

 

[martin-s]

Why make DNS (such an important service) such a weak link?

Personally, I'd use (and do use) the free Rackspace cloud DNS service instead:
http://www.rackspace.co.uk/cloud/dns

 

[timter51]

Why make DNS (such an important service) such a weak link?

Personally, I'd use (and do use) the free Rackspace cloud DNS service instead:
http://www.rackspace.co.uk/cloud/dns

To be honest it's a case of me not knowing there were other ways of doing it, all my web developing days I've just stuck with what my webhosts have automatically set for me. So being able to use different DNS hosting services is a whole new world.

With Rackspace do set both NS1 and NS2 (or more) to use it, or do you just use it for NS2 as backup?

 

[martin-s]

They have a dashboard for you to configure your DNS (A, C, MX, etc). Then you just need to setup these two nameservers on your hostname records with your domain registrar:

dns1.stabletransit.com
dns2.stabletransit.com

 

[Adam H]

Martins right, Single point failure...... Cloud based DNS like rake space, Cloudflare etc will suit most VPS and Dedi owners, just remember doing so means all DNS entries need to go through that service so its important to have entries such as DKIM and SPF for your mail validation.

If you are feeling adventurous you could purchase some decent VPS in different datacentres around the globe and run them as DNS only machines but probably not something you'd want the bother of doing

 

[Edwin]

http://www.dnsmadeeasy.com/

$29.95 a year, solid as a cart horse!

 

[martin-s]

Why pay when you can have Rackspace for free?

 

[timter51]

Thank you chaps for your help, very useful, I need to sort this out obviously.

@martin-s it looks to me as though Rackspace DNS hosting is only a free add-on service for current customer? Unless I'm looking in the wrong place!

@invincible I use Google Business Apps for my email, with the MX records set accordingly. This is one of my main concerns with how it is at the moment, if someone tries to email me when my server's DNS is unreachable for whatever reason, they will get an instant bounc back. Not a good thing for business!

@Edwin looking good thanks, it's on my list

If I were to use one of these DNS hosting services, be it Rackspace, dnsmadeeasy or whoever, I've got to make sure the transition is smooth with as little downtime as possible. So I take it I would need to set every single record properly at the DNS host first, and then change the nameservers on the domain? Could I still use my server as NS1 and NS2, then have a DNS host as NS3 and NS4 for redundancy? Or, if I'm going to do this, should I just switch completely to a DNS host?

 

[martin-s]

@martin-s it looks to me as though Rackspace DNS hosting is only a free add-on service for current customer? Unless I'm looking in the wrong place!

You don't actually need to use any of their other services if you don't want to. Sign up and see

 

[davedevelopment]

If I were to use one of these DNS hosting services, be it Rackspace, dnsmadeeasy or whoever, I've got to make sure the transition is smooth with as little downtime as possible. So I take it I would need to set every single record properly at the DNS host first, and then change the nameservers on the domain? Could I still use my server as NS1 and NS2, then have a DNS host as NS3 and NS4 for redundancy? Or, if I'm going to do this, should I just switch completely to a DNS host?

Yes, you would need/want to set up every record properly at the new provider.

You could add the new DNS service to the existing one, just remember to keep both sets of records up to date. Personally, I'd replace what you already have and keep one canonical source for the records.

It's a little more complicated than some of the other offerings, but we use Route 53 from AWS. It costs pennies and we're happy with it.

 

[martin-s]

Because you're not moving servers, just DNS providers, there shouldn't be any downtime.

Just set it all up at the new DNS provider, then when you're ready, update the nameserver settings on the domains.

If you were moving sites across IPs as well, you'd set the TTLs on the existing DNS down to 5 minutes 24-48 hours ahead of the move.

 

[Edwin]

Sounds like you need some kind of backup email service too.

If you want absolutely maximum resilience, you could go for:
- primary DNS hosted somewhere
- secondary DNS (which essentially mirrors the primary DNS) hosted somewhere else
- backup email, either provided by the primary DNS provider if they're not also your email provider, or by the secondary DNS provider, or by a third company. For example http://www.dnsmadeeasy.com/services/mailservices/backupemail/

There's no reason other than simplicity (which is, admittedly, often a good reason) why responsibility for the above 3 can't all be handed out to different companies, and potentially even different companies from your web hosting and/or email provider.

So at the maximum, you could have a relationship with 6 companies:
- domain registrar
- hosting
- email
- primary DNS
- backup DNS
- backup email

And you could pick a "best of breed" solution for every one of the above.

Of course, you could probably cut the list down to 2 or 3 providers by picking companies that do e.g. primary DNS and backup email, or secondary DNS and backup email, or hosting and primary DNS - but what I'm trying to emphasize is that there's no obligation to consolidate everything if resilience is your #1 tip-top priority.

 

[Edwin]

NOTE: the way a backup email service works is that you would specify their server in the MX configuration section of your domain's DNS configuration, but give their server a lower priority than the one assigned to the main email server.

That way, email will be delivered to the main server unless it can't be reached; at that point, it will automatically get diverted to the backup email server. The backup email server will "catch up" once the main server is back up by sending on the emails it stored during the downtime.

(It's possible to have more than one backup email server specified, if you're looking to add more .9s reliability)

 

[Adam H]

If your using Google Apps for mail and have setup the MX records via a DNS provider ( I.e DNS made easy, rackspace, cloudflare ) then there is no need for an email fallover as the MX records will be live still regardless of whether your VPS is online or not.

 

[Edwin]

If your using Google Apps for mail and have setup the MX records via a DNS provider ( I.e DNS made easy, rackspace, cloudflare ) then there is no need for an email fallover as the MX records will be live still regardless of whether your VPS is online or not.

Not strictly true, as per my post above. Yes, email would work even if the hosting fails. But if the email provider itself goes down, some emails could bounce or fail. With a backup email service waiting in the wings, that can't happen.