As the volume of internet rapidly increases, the number of IPv4 addresses available is quickly declining, while transition to IPv6 is being delayed. As a interim solution, Variable-Length Subnet Masking(VLSM) addressing scheme, which varies the length of each IP address allowing more efficient, is being used. This paper suggests effective example of network based on virtual network with topology designed using VLSM charting rather than usual theoretical approach in VLSM, which allows more efficient use of address space.

In this paper , the web accessibility of institutions and organizations that are related to disaster response we evaluate analysis. Along with the legal enforcement of Web accessibility, It is because shall comply with web accessibility. we have applied the K-WAH4.4 as an evaluation tool for web accessibility compliance of actual conditions. Look at the degree of compliance with the six detailed procedure of the web site, we request to the improvement of Web accessibility. Based on the guidelines 2.0, looked to the insufficient compliance rate at 61.8%. Then, we propose the need for improvement to enhance Web accessibility.