My aim was to do a feasibility treatise. The subject of the treatise is Loop-Free Alternates implemented into Quagga routing Software. The beginning of the thesis I describe the Open Shortest Path First routing protocol. I create a test network, and test case. This test case is point at the weakness of the Open Shortest Path First protocol. The convergence of the OSPF is too slow, when occur changes of the network topology. The OSPF can not be corrected quickly. Nowadays the applications of Internet can be sensitive the slow convergence. The IP Fast ReRoute technology is able to develop the convergence of the OSPF. I introduce the main part of the Quagga, the IPFRR - IP FastReRoute technology and the type of the LSA. I create test cases, and take modification into the code. I am able to upload test-LSA into the Quagga. This method is providing a testable environment. I take the most important steps to implement Loop-Free Alternates under Quagga. This treatise is the first step of a long term work.