Centos – Can’t ping website but can browse it

You can't ping ports, as Ping is using ICMP which is an internet layer protocol that doesn't have ports. Ports belong to the transport layer protocols like TCP and UDP.

However, you could use nmap to see whether ports are open or not

nmap -p 80 example.com

Edit: As flokra mentioned, nmap is more than just a ping-for-ports-thingy. It's the security auditers and hackers best friend and comes with tons of cool options. Check the doc for all possible flags.

You have a name resolution problem. Based on what you've implied I'm assuming it's a DNS problem. Here are some steps to take:

1. Identify your internal DNS server(s). Identify the appropriate DNS zone on the DNS server(s). Verifiy that the DNS zone is configured to allow dynamic updates. If this is an AD related zone you can allow secure updates only. If this is not an AD related zone then you need to allow both secure and unsecure updates.

2. Make sure that both database servers are configured to use the DNS server(s) identified in step 1 for DNS name resolution.

3. Make sure that both database servers are configured with a DNS suffix that matches your DNS zone. This will be the case if this is an AD domain and both database servers are joined to the domain.

4. Verify that the correct A (host) records are registered in the DNS zone for both database servers. If they aren't registered or if they aren't correct, then delete the incorrect record and reregister it from the applicable server by running ipconfig/registerdns from a command prompt.