In my description of HostNameComparisonMode I neglected to explicitly mention how the wildcard-ness affects your port#. In short, we will ignore the port# in our match if you have chosen StrongWildcard or WeakWildcard, and we will include the port# in our match if you choose Exact.

This behavior is especially useful when using network monitoring intermediaries. Let’s say you have an intermediary listening on TCP port 8080 that forwards traffic to your service on port 8081. The Via on the wire for net.tcp would be net.tcp://mymachine:8080/a/b/. When this intermediary forwards the packets to your service listening at port 8081, the request would succeed only for Wildcard bindings.

Actually setting up a intermediary takes a few more tweaks to your service and client that I’ll go into more detail about next week.