Common networking problems

Bad names and other DNS name resolution failures Missing capabilities Bad HTTP headers are sent Incorrect use of completion handlers in UI threads App bugs Network problems Connection timeouts Connection resets Difference in network topologies

Tools: Visual Studio

Tools: CheckNetIsolation

CheckNetIsolation helps you determine proper network capabilities There is no need to open firewall rules for Metro style apps

Tools: Fiddler

Used for debugging HTTP traffic CheckNetIsolation can also help set the environment to use Fiddler Some times headers have valuable information, useful when identifying a problem

Fiddler options, connections tab Enable “Allow Remote Computers to Connect” From elevated cmd prompt CheckNetIsolation LoopbackExempt –a –n=[Package Family Name]

Tools: Event Tracing for Windows

Sometimes problems are hard to reproduce, can’t be stepped through using the debugger Might happen in elaborate situations We need a record of the history of the events

Tools: Netmon

Sometimes to understand a problem we have understand how data is sent and what is really sent, over the wire

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