I modded the python server so it will send M_O_TOPO_REQ packets and they look fine on Wireshark.

Pic from Wireshark. Shows the packet the server sends to the root node asking for topology.
However, the root node reports over the serial "topo option format is illegal".
Why is it illegal? It seems to be okay.
Also, as a secondary question, what are piggyback flow permit and piggyback flow request flags for?
Thank you for your attention.