According to "How To Run Your Own Name Servers With ISPConfig And GoDaddy - Page 3" It says "(The steps from this chapter have to be done on ISPConfig server #2/ns2.erikturk.com.)" Does that mean that I need to install ISPConfig on my second DNS? If so, how they will know about each other? Will they replicate their data? Thanks!
yes. Through the BIND zone transfer faeture. You musts etup the dns records on your primary server and add a slave DNS record on your secondary server that replicates the data automatically. yes.