IPAddress.HostToNetworkOrder ?

Hello, I want to write the varible: UInt32 m_spi =1000; to one field of the etherpacket and send it through ethernet position = 4; Array.Copy (BitConverter.GetBytes (IPAddress.HostToNetworkOrder( (UInt32) m_spi), 0, buffer, position, 4); ethereal should sniff this packet with value lke this: m_spi= 0x000003e8 but my it show m_spi = 0x00000000 for my packet. What have i doing wrong ? regards !