Packetip_data
          Return data part as String.
        
ip_df?
          Return true if Don't Fragment bit is set.
        
ip_dst
dst
          Return destination IP address as IPAddress.
        
ip_flags
Return the value of 3-bits IP flag field.
ip_hlen
Return header length. (Unit: 4 octets)
ip_id
Return identification.
ip_len
Return total length.
ip_mf?
          Return true if More Fragment bit is set.
        
ip_off
Return fragment offset.
ip_proto
Return the value of protocol field.
ip_src
src
          Return source IP address as IPAddress.
        
ip_sum
Return the value of checksum field.
ip_tos
Return the value of TOS field.
ip_ttl
Return TTL.
ip_ver
Return IP version.
to_s
Return string representation.