Unable to connect to sql server 2012 named instance:error 26

To brief a little, I have created 2 VM's; both VM's have same h/w and s/w configuration. They are running Windows server 2012.

Have installed SQL Server 2012 on them; both installation have 2 named instances; like

VM1 have SQLmaster VM2 have SQLSlave

Now, when I try to connect to instance in VM2 from VM1 I am getting error:26

"SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified"

Tried the solution/suggestions mentioned in below blogs but no luck.

http://blogs.msdn.com/b/sql_protocols/archive/2007/05/13/sql-network-interfaces-error-26-error-locating-server-instance-specified.aspx

http://social.msdn.microsoft.com/Forums/en-US/sqlsetupandupgrade/thread/69b8e727-eb51-4de1-b298-b3ff316bd071/

Any idea, how can I get rid of this.

NOTE: I am actually trying to configure "sqlserver 2012 alwayson" on this servers but getting stuck here.

Thanks.