IP addresses in Witnet protocol may be IPv4 or IPv6 and they are encoded as bytes, as a concatenation of ip and port.
The kind is inferred based on the length: 6 bytes for IPv4 and 18 bytes for IPv6. The fields are encoded using Big-Endian representation.
|| denotes concatenation)
[u8; 6] => (Ipv4) ip || port [u8; 18] => (Ipv6) ip0 || ip1 || ip2 || ip3 || port