If IPv4 addresses are greater then 127.255.255.255 e.g. 192.168.1.1, Graph is not correctly fulfill from BGP-LS.

LinkStateGraphBuilder thrown an error due to negative key value. Indeed, the link key is derived from the IPv4 address, but cast is not correctly done and signed value is propagated instead of 64 bits unsigned integer.

Ipv4toKey() function in LinkStateGraphBuilder wrongly compute Long from an
IP address. IP address above 128.0.0.0 are converted as a negative value
which trigger a java exception when converted to Uint64. Need to change the
function to use ByteBuffer wrapper like for Ipv6ToKey() function.