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General Discussion

Chris Jones
Chris Jones
9,385 Points
Posted by Chris Jones
Chris Jones
9,385 Points

DNS - Suggestions/recommendations on TTL

Hi guys,

Just watched the DNS video series - very good! One thing I was hoping would be covered in more detail was TTL. This is a topic I seem to revisit every year.

In my latest domain template, I've gone for a very low TTL. I understand that higher is better for live sites so there's less lookups but I have found this lower TTL nicer to work with when you need to make a DNS change quickly. Most of my sites are small businesses, low traffic (5000 visitors or less per month) so I don't think this is a big issue.

If we are talking in general, what are your preferred TTL values? Does anyone have a setup that they think strikes a good balance between lookups and flexibility?

Below is my DNS setup for most sites if they don't use Google Apps: 

Refresh: 7200
Retry: 900
Expire: 1209600
Minimum TTL: 300

My simple domain template looks something like this:

<domainname>             A              1.2.3.4                   TTL    3600
<domainname>             A              1.2.3.4                   TTL    3600
ftp.<domainname>        CNAME    <domainname>.    TTL    14400
www.<domainname>    CNAME     <domainname>.   TTL    14400
<domainname>             MX            <domainname>     TTL    3600
<domainname>             TXT           ie SPF                   TTL    3600

Looking forward to reading other people's DNS / TTL setups and suggestions.

Thank you, Chris.

Musa Bin majid
Musa Bin majid
419 Points

Hi, can you please show me the path/url/tracks(within treehouse) regarding the DNS series that you mention.. i would like to know more

i'm a noob regarding DSN, especially nameservers @ reverse etc..

thank you

Christopher Peters
Christopher Peters
1,927 Points

Hi Musa Bin majid, you can find DNS Basics in the Technology Foundations Deep Dive. Here's a direct link! http://teamtreehouse.com/library/technology-foundations#dns-basics

Musa Bin majid
Musa Bin majid
419 Points

Hi Christopher,

Tq for the info ^_^

1 Answer

Alan Johnson
Alan Johnson
7,625 Points
Alan Johnson
Alan Johnson
7,625 Points

I've typically done super low TTLs on personal sites (60s or so), but on larger apps I usually set up a higher TTL.

On larger sites (like Treehouse!), there's usually a good bit of planning going on with DNS changes anyway, so we'll usually turn the TTL down low before a change (at least the current TTL amount of time before the change, but ideally 2-3x as long as the current TTL) and then make the change, and then crank the TTL back up afterward.