You can confirm that each Open Server is available by selecting ServerObject > Ping Server from the DSEdit utility.
Alternatively, you can confirm that each Open Server is configured properly by connecting to the database using an Open Client application such as the isql utility.
To start isql running on the primary site database, type
isql -U DBA -P sql -S PRIMEDB
The Open Client isql utility is not the same as the SQL Anywhere Interactive SQL utility.