RTF_UP 0x0001 RTF_GATEWAY 0x0002 RTF_HOST 0x0004 RTF_REINSTATE 0x0008 RTF_DYNAMIC 0x0010 RTF_MODIFIED 0x0020 RTF_MTU 0x0040 RTF_WINDOW 0x0080 RTF_IRTT 0x0100 RTF_REJECT 0x0200