TCP/IP?????????

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TCP/IP?????????

• ??????
• ???
• Email mli_at_ccms.ntu.edu.tw
• Phone [phone]

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? ?

• TCP/IP??
• TCP/IP?????
• TCP/IP????????
• ?????
• ?????

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TCP/IP??

• 1967?DARPA (Defense Advanced Research Project
  Agency) ??ARPANET (Advanced Research Project
  Agency NETwork) ????
• 1983???????(Internet)
• 1985???NSFNET (National Science Foundation
  NETwork)

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TCP/IP??(Cont.)

• ?????????,SNMP (Simple Network Management
  Protocol)
• ?? ISO (International Organization for
  Standardization) ??,???????
• IAB (Internet Activities Board) ????????????

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TCP/IP??(Cont.)

• IETF (Internet Engineering Task Force)???????????
• ???????????????,???RFC (Request for Comments)
• NIC (network Information Center)????RFC??

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TCP/IP?????
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TCP/IP????

• ????? (Network Interface Layer)
• ????? (Internet Layer)
• ????? (Transport Layer)
• ??? (Application Layer)

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?????

• ??OSI????????????
• ????????
• ???????????????

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?????

• ?????????????
• ???????????
• ??????????????
• ??????????
• ????????

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?????

• ????????(TCP)?????????(UDP)
• TCP?????????
• TCP???????????????
• TCP??????
• UDP??????????

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???

• ?????????
• ??????????
• TELNET
• FTP
• SMTP
• DNS

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????????
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?????(1)
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?????(2)
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??????(IP)

• ???????? (Connectionless Service)
• ?????? (Best-effort Delivery)
• ????
• ??
• ??
• ??????????

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IP Header??
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IP Header

• Version IP??
• Header Length IP header??
• Type of Service ???????????
• Total Length ????????
• Identifier ??????????????

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TOS ??
Bits 0-2 Precedence. 07.????????? Bits 3
0Normal Delay, 1Low Delay Bits 4 0Normal
Throughput, 1High Throughput Bits 5 0Normal
Reliability 1High Reliability Bits 6-7 ??????
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IP Header(Cont.)

• Flags ???????
• ?? 0 ??
• ?? 1 0??????,1??????
• ?? 2 0???????fragment,1????????
• Fragmented Offset ??????fragment???segment??????
  ,?8?????offset???

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IP Header(Cont.)

• Time to Live segment?????????
• Protocol IP????????
• Header Checksum IP header?????
• Source Address ????IP??
• Destination Address ????IP??

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IP Header(Cont.)

• Options Segment???????
• Padding ?header???32?????

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IP ??

• IP???32????????
• IP???? lt????, ????gt
• IP????? dotted-decimal???(??????)

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?????????? ?32??????
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IP????

• ??A, B, C????????????
• ??D?????????????????
• ??E?????

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???IP????
IP?? ????,????
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IP????
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????

• ???? IP???????,?????0
• ??,140.112.254.4,?????B?????,?????140.112.0.0
• ???????????????

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??A,B,C?????
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???????
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???(subnet)

• ??? ?IP????????,?????????????
• IP?? ????, ?????, ????
• ??,??B?140.112.0.0,??????8???????,140.112.1.0
  140.112.254.0,?254????

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???(Cont.)

• ?????????(subnet mask)???????
• ??????????1?,????????
• ??????????0?,????????

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???(Cont.)
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???(Cont.)

• IP??????????????,?????????
• ??????0,?????????
• ??????1,??broadcast????
• ??IP???????????????? 2n 2,n???????????????

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???(Cont.)

• ??,140.112.0.0 (255.255.255.0),????????????28 2
  254 ,???????????28 2 254

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IP Prefix

• CIDR (Classless Interdomain Routing)
  ????IP??(??A, ??B, ??C)????IP Prefix
• IP Prefix??? IP?? / ?????????
• ??,140.112.3.0/24

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IP Prefix
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??????
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ARP Address Resolution Protocol

• IP segment?????????(????????)
• ARP???IP??????????????
• ?????????????????

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?????

• ??????????????
• ???????
• ??????(TCP)
• ???????(UDP)

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TCP?????

• ??????????,??????????????
• ????????(ACK), ?????(Checksum),
  ???(Timer)?????,?????????
• ??Window Control??????

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TCP Header ?? (Transmission Control Protocol)
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TCP Header

• Source Port Destination Port ????????????
• Sequence Number ?????????????,??????????
• Acknowledgment Number ????????????,?????????
• Header Length TCP Header???

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TCP Header(Cont.)

• Reserved ???????
• Flags ?6?bits???,??????????
• URG ????
• ACK ????,??????????
• PSH push function
• RST ????

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TCP Header(Cont.)

• SYN ??????
• FIN ????????
• Window Size ???????,??????????(?8???????)
• Checksum ??????
• Urgent Pointer ?????URG flag?1?,??????

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TCP Header(Cont.)

• Options ???????????????????????
• Padding ?header???32?????

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TCP???????

• ??,?????????????
• ???????,?????????
• ???????
• ?????????

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Three-Way Handshack
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Three-Way Handshack
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UDP Header ?? (User Datagram Protocol)
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UDP Header

• Source Port ????????
• Destination Port ????????
• UDP Length ????????
• Checksum ??????