How a DNS entry works

Basically, there are two methods to address a target system. Either you directly specify the IP address: the CS141 will then address the system directly without involving other system services or server. Or, instead of an IP address, it is possible to use a host name: by doing so, the CS141 will send a request to a responsible DNS service and ask for the IP address assigned to the host name.

Both methods come with their own advantages and disadvantages

• When using host names (e.g. database.steel-colossus.intra), the user can identify the target relatively well, but is dependent on a well-functioning network: 

  the resolution of host name > IP address is managed by a DNS server. When using host names, the CS141 also requires a DNS server, e.g. if RCCMD control signals have to be transmitted to a specific RCCMD client:

  For each control signal, the responsible DNS server must first be contacted and asked for the IP address of the host. 

  If a network breaks up into individual segments as a result of a fault, a segment without a DNS server will no longer be able to resolve host names.

   

• Using an IP address is a little more independent to a certain extent, because there is no need for a DNS server. 

  The target IP and network segment is already known, and the RCCMD control signals will function accordingly in the event of a network disturbance close to the DNS server.  

  On the other hand, this method requires fixed IP addresses. If a DHCP server dynamically manages and reassigns IP addresses according to its function, the CS141 job management can hold out-dated information about the target IP address - in case of an emergency, the CS141 may send valid RCCMD commands, but address the wrong target.