BIND DNS SERVER in my Production environment

Question

I would like to start working with a local DNS server in my production. right now instead of working with DNS I'm working with IP Addresses.

I would like to know what is the effect of working with DNS Server instead of IP Addresses. can it cause a real Overhead in my network?

which DNS server do you most recommend to work on Centos Linux?

score 2 · Accepted Answer · answered Mar 08 '12 at 14:06

2

Using DNS in a local network will usually not create any noticeable overhead, as long as you allow for a TTL greater than zero. This will mean that the clients cache the entry and don't ask again for the duration of the TTL. If your entries are long-lived, using a TTL of one day (86400) is not uncommon.

answered Mar 08 '12 at 14:06

Sven

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Thank you for your answer!! what if I would like to use ttl of 1 hour. I need it for DRP in case on of myservers goes down then I will change the DNS. is that too much? – edotan Mar 08 '12 at 14:17
Well, I usually use 300 seconds and don't have any problems. Even when I had a often-used system where I accidentally left the TTL at 0, I didn't noticed any real impact. – Sven Mar 08 '12 at 14:55
Thanks aagin!! do you know if there are DNS applications that can do fail over. (something like GEO DNS). I would like to use one in case I have a server Down. – edotan Mar 08 '12 at 15:03
None of this is related to DNS functionality. DNS is redundant by design, but you need to understand how to use it properly. – adaptr Mar 08 '12 at 15:15
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@adaptr: DNS is *not* redundant by design, it just makes it pretty easy to become redundant. If for some reason, you run only one DNS server for a zone, private or public, redundancy is gone and your DNS goes down with the single server. – Sven Mar 08 '12 at 20:18
...and since this was *incorporated into the design from the very start*, we call it "redundant by design". – adaptr Mar 09 '12 at 08:26

score 2 · Answer 2 · answered Mar 08 '12 at 16:29

As Sven said, operating your own DNS server shouldn't really have appreciable overhead (In fact you'll probably find slightly less external network traffic if you also set the DNS server up to be a caching resolver -- Looking up www.google.com can be served from the cache for as long as the www.google.com TTL says the entry is valid.

In short, drawbacks: Almost none (you have a DNS server to manage now, but that's not really hard).
Benefits: Almost infinite (using hostnames instead of IPs? SO much better!)

Software-wise I would recommend BIND, which should come installed by default on CentOS (and if not, it's definitely available in the package repo). It is the reference implementation of a DNS server, superbly documented and well understood by pretty much everyone.

I would also give you my standard recommendation for anyone setting up DNS anywhere: Buy and read a copy of DNS and BIND. Even if you're not using BIND the chapters on DNS are important to read and understand.
This book will help keep you from making disruptive mistakes, and the knowledge you gain by reading it will help you fix any mistakes you do make quickly.

BIND DNS SERVER in my Production environment

2 Answers2