I can’t connect to the Platform Builder Remote Tools over KITL. What is wrong?

A likely cause of this problem is that your PC has its MTU (Maximum Transmission Unit) size set to less than 1500. Many VPN and other network services set the network connection's MTU to optimize the efficiency of the network traffic. Most set the MTU to around 1300 bytes (the default is 1500 bytes).

MTU is short for Maximum Transmission Unit, the largest physical packet size, measured in bytes, that a network can transmit. Any messages larger than the MTU are divided into smaller packets before being sent.

The problem with this is that KITL sends packets larger than 1300 bytes, which results in fragmented packets.  The KITL tools and connection cannot deal with the fragmented packets, and so the tools connection doesn't work and the KITL link itself may become unstable.

To fix this problem:

  • Open Registry Editor >> start | run | regedit
  • Now we need to set the MTU to 1500
  • HKEY_LOCAL_MACHINE | SYSTEM | CurrentControlSet | Services | TCPIP | Parameters | Interfaces
  • Do a 'Find' on Interfaces and look for 'mtu', there will be multiple instances of the MTU key that show up.
  • Set each one to 1500.
  • Now reset your machine.