Are there any particular disadvantages to having the DNS on the same server as where the site is? I'm in a situation where the web host doesn't do DNS for its clients, so I have to either choose to put the DNS on the server itself, or find some other way (ie: third party DNS).

Thanks,

If you're in a simple hosting situation, I don't see any disadvantage as long as you've got outside monitoring making sure that both services are up and running. You'd be running into one of those one-without-the-other situations otherwise, which would render the server more or less useless. One consideration is security, though. It'd be nice to have them on two servers so that if someone does break through bind or whatever, that they couldn't get to sites, and vice versa.

For most situations, though... both on one box would be fine, IMHO.

George

Well, if you've got services over multiple machines - then you'd also want to spread the DNS over multiple machines because if the DNS breaks then it will take everything down with it.

If you've only got services on one machine - then putting the DNS on that one box wouldn't be an issue (in my opinion).

--Shaun

If you're going to split DNS off from web services, and you've got a number of servers to manage, do yourself a favor. You should want to spread DNS across a few machines, and it would be prudent to do it on a couple of different netblocks. Too often (even with "big" companies) do I see ns1.domain.com on 123.45.6.1 and ns2.domain.com on 123.45.6.2 for multi-server hosting firms. If for whatever reason you knock 123.45.6.0/24 out of your routers, or if ARIN repossesses, or your upstream stops routing it... Your entire business goes kaput. :bawling:

George

Thanks for the replies. All services (ie: site) will be on one server only.

You can setup the dns in the same server were the web server is running. However you face several possible problems:

1- You have to take care of having your dns server up, if it goes down, your site wont be accessed

2- DNS servers, as every software can have exploits in it, and can compromise the whole server. You are openning another window (port) in your box so an exploiter can use it to enter. Keeping an eye on updates can solve partially the problem.

3- Ok, DNS doesn´t use too many resources, but maybe your dns receive enough hits making it to spare some resources in your server.

4- If yo are planning to host dns in your server, probably you wont have redundancy, nor distribute dns requests among other servers.

You may use a free service like everydns.net and/or granitecanyon.com in order to use a third party dns server and not to use your own dns server.

They are very reliable so you probably wont hav problems with them.

There are more issues with hosting DNS only on your web server:

1. If your server is down, people won't get a "is currently unreachable" error, they will get a domain does not exist or equivalent. This often means that rather than coming back later because it's clearly currently down, they'll never come back because it's as though your domain doesn't exist.

2. Usually, when someone sends you email and your server is down, it will queue on their SMTP server until your box xomes back and then deliver it. However, if you have DNS on the same box, then your MX record will not resolve and the mail delivery will simply fail immmediately.

3. Some ccTLD's require you to have 2 DNS servers on separate servers (though, in practice, it's impossible for them to tell if this is the case).

All in all, I think it's a very bad idea, unless it's just a hobby/personal server that you don't care too much about. If it's got anything to do with an online business, I think it's a very bad idea.

I'd recommend you do what CobaltCuban suggested:
You may use a free service like everydns.net and/or granitecanyon.com in order to use a third party dns server and not to use your own dns server.

Simple, cheap and avoids the pitfalls.