It seems the DNS resolution server that my CentOS virtual machine uses by default isn't resolving a few domains. I've temporarily switched my server to use dnsmasq along with Google public DNS.
Faulty resolution
[azureuser@node1 ~]$ nslookup
> server 100.79.10.80
Default server: 100.79.10.80
Address: 100.79.10.80#53
> www.chaldal.com
;; connection timed out; trying next origin
Server: 100.79.10.80
Address: 100.79.10.80#53
** server can't find www.chaldal.com: NXDOMAIN
Works fine when switched to google public DNS:
[azureuser@node1 ~]$ nslookup> server 8.8.8.8
Default server: 8.8.8.8
Address: 8.8.8.8#53
> www.chaldal.com
Server: 8.8.8.8
Address: 8.8.8.8#53
Non-authoritative answer:
www.chaldal.com canonical name = chaldal.com.
Name: chaldal.com
Address: 23.97.76.235