>The Github IPv6 Proxy can only be used for traffic to Github using a VPS from TransIP which uses IPv6.
The requested URL /cs155/hw_and_proj/pp1/boxes-2.3.tar.bz2 was not found on this server.
From https://crypto.stanford.edu/cs155/hw_and_proj/pp1/boxes-2.3.... which is the VM image link.