I'm a newbie for microsoft technologies and I'm having problems in connectivity part for SQL Server 2014. This is probably an easy issue but I'm stuck.
I've 4 servers. One of them is the Active Directory Domain Controller, one is the application server and the others are being used for SQL Servers. Since it's a connectivity issue, IP's for servers are; -AD DC : 10.6.0.100 ( Also the DNS Server ) -APP : 10.6.0.110 -SQL 1 : 10.6.0.120 -SQL 2 : 10.6.0.121
I've successfully created a failover cluster (DBCLUSTER) and set the IP address of the FC as 10.6.0.130 ( which is not an actual server IP, I really don't get this part.. ).
Later, I've created an AlwaysOn Availability Group for sql servers. I've successfully created the AG without listener. I could connect to servers from each other, database syncs without problem. Then, I've created a listener (AG-LISTENER) and set it's ip as 10.6.0.131 ( which is not an actual server IP, again? ) and set it's port to 5525. It gave no problems.
So I wanted to test connectivity. When I wanted to make connections from APP server to directly SQL 1 or SQL 2, I can connect without problem. But when I try to connect to AG-LISTENER, it cannot find it on network. When I check the DNS records. I can see it as it's being hosted on 10.6.0.131.
When I tried to ping to AG-LISTENER from AD-DC, APP, SQL 2 servers, it responds that the destination host is unreachable (it's pinging 10.6.0.131 but the response comes from the IP's of AD-DC, APP and SQL 2 servers). It can connect from SQL 1 server, which is the primary for AG.
I've checked the firewalls, there's no problem. But I think this is an network issue which I have no clue.
PS: Servers are operating on Windows Server 2012 and are not being hosted on Azure.
Cause of the problem was the network topology of the service provider. It's found that IP's 10.6.0.0/32 could be used by other servers of other customers. So they've allocated us another IP block which only we have access to and it worked like a charm.