Your use case might be to route all traffic through an endpoint, in which case https://ipleak.net https://ipleak.net will tell you what your browser is giving a

Your use case might be to route all traffic through an endpoint, in which case https://ipleak.net https://ipleak.net will tell you what your browser is giving away. The other use case —- what this article is about —- is a persistent bridge between private subnets. In general, you can worry about this channel to the same degree that you worry about SSL. To test either, the network sniffer Wireshark is a good start.