// message for an AddrProto address
message addr {
    // address type. from addr.h
    required uint8 type = 1;
    // for IPv4 and IPv6 addresses, the port (network byte order)
    optional data("2") ip_port = 2;
    // for IPv4 addresses, the IP address
    optional data("4") ipv4_addr = 3;
    // for IPv6 addresses, the IP address
    optional data("16") ipv6_addr = 4;
};