ASP.Net check if user is internal or external

问题

Can you suggest me some ways on how to identify if a user is accessing my web application internally or externally?

Some methods i tried are:

• Check browser URL (http, internal - https, external)
• using Request.isSecureConnection

I just need some additional insights.

BTW, i am using a Web Part.

Thanks.

回答1:

Basically, you could do that by checking the client's IP address. There are 3 ranges that can be treated as local (or internal) networks. The 3 ranges are (A , B and C classes)

10.0.0.0/8 (255.0.0.0)  24 bits
172.16.0.0/12 (255.240.0.0) 20 bits
192.168.0.0/16 (255.255.0.0)    16 bits

You can use bit wise masking to check if ip is in any of those ranges, just turn ip in HEX representation

254.245.245.254 = 0xfefefefe

来源：https://stackoverflow.com/questions/7989437/asp-net-check-if-user-is-internal-or-external