Description:
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---
From manual page: http://www.php.net/function.checkdnsrr
---

Root issue: I'm having networking problems when setting up the session handler to use Redis.

If I setup the session handler using an IP address pointing to my Redis host, it works fine. If I use a domain (DNS or my linux /etc/hosts file) it doesn't work, sessions are not saved in Redis.

So i've started looking into some networking related function to test this behaviour and see if I could find a DNS-related issue somewhere, and here I've encountered weird results for checkdnsrr() function.

Hopefully, fixing these would fix my Redis connection issue.

Test script:
---------------
/**
In AWS using route53, I've set 2 DNS records: 

- one A record        route53.myapp.com  >> 10.1.1.101   
- one CNAME record    route666.myapp.com  >> route53.myapp.com   

*/


// >> control the OS/hosts is seeing the DNS records: 
var_dump( gethostbyname('route53.myapp.com'));      >> 10.1.1.101 
var_dump( gethostbyname('route666.myapp.com'));     >> 10.1.1.101 




// My first test: 

var_dump( checkdnsrr('route53.myapp.com', 'A'));      >> true

var_dump( checkdnsrr('route53.myapp.com'));           >> false  !!! 

### If I have a A record, looking for ANY type of records should return true too.




// My second  test:
var_dump( checkdnsrr('route666.myapp.com'));          >> true
var_dump( checkdnsrr('route666.myapp.com', 'A'));     >> true  !!!
var_dump( checkdnsrr('route666.myapp.com', 'CNAME')); >> true

### If route666 is a CNAME, testing it's a A record should return false.