I take it you mean Linux based Network Load Balancing ... first of all there is
LVSThe most simple solution is a basic "DNS round robin" solution. Mind you, it does no real load balancing, it just distributes the requests one after the other. If one node of the NLB Cluster fails, this version still sends the users to it

You should define a bit more what HW you have available for that purpose (single or dual NICs) and if you want loadbalancing with failover or just the simple DNS solution ... and with paralel .. do you mean the ISP controlpanel or just 2 (or more) webservers?
cheers
Klaus