We are developing the diverse reception system, which uses route diversity between a broadcasting satellite and IP network to compensate for 21-GHz band satellite broadcasting rain attenuation. This system will be able to improve service availability by covering a rainy area (where satellite broadcasting occasionally cannot be received due to rain attenuation) with a signal from a sunny area via an IP network. This system also uses a common forward error correction (FEC) technique between the broadcasting satellite and IP network, which enables seamless channel switching and makes the reception algorithm common between both channels. In this paper, we focus on a FEC technique in IP network, which is key to achieve this system. We evaluated the error-correction performance in an IP network with the LDPC codes designed for satellite broadcasting through computer simulation. We also propose a method of adjusting the LDPC coding rate with padding bits according to the transmission characteristics of broadcasting satellite and IP network, which reduces IP traffic congestion. Therefore, the LDPC codes designed for satellite broadcasting can achieve adequate error-correction performance even in an IP network with packet loss.