Instal .NET Core 2.1 Runtime on Raspberry pi 3/2

 

sudo apt-get install curl libunwind8 gettext 
curl -sSL -o dotnet.tar.gz  https://download.microsoft.com/download/9/1/7/917308D9-6C92-4DA5-B4B1-B4A19451E2D2/dotnet-runtime-2.1.0-linux-arm.tar.gz
sudo mkdir -p /opt/dotnet && sudo tar zxf dotnet.tar.gz -C /opt/dotnet
sudo ln -s /opt/dotnet/dotnet /usr/local/bin

Test .Net Core 2.1 Runtime 
dotnet --info