A version hash is used by crust to control validity of connecting node. This hash is based on 2 environment variables:
-
CARGO_PKG_VERSION which is set automatically by cargo to the version of the binary being build. This is the way that the network rejects older vaults.
-
NETWORK_VERSION which can be set manually at compile time. I proposed to use this variable to prevent accidental connection to Maidsafe network when we wanted to connect to community network or vice-versa. This is useful when both networks use vaults based on the same sources, and so cannot be discriminated by CARGO_PKG_VERSION.
EDIT:
In current master branch of crust the 2 environment variables controlling connecting nodes have been replaced by only one element: network_name parameter in config file
The advantage is that there is no risk of errors anymore when one wants to launch an independent network because the seed IP addresses are provided together with the network name in the same file.
The drawback is that automatic rejection of older vaults is lost. The sensible workaround is to include the vault version in the network name.