CERNET??????

1
????????

• ??????????
• CERNET??????
• ???
• 2005.8.15

2
????

• Internet?????????
• OSI???? vs. TCP/IP???
• ???????? vs. ???
• IP?????????????????
• ????DNS?HTTP?FTP?E-mail
• ??????????
• ????
• ????????

3
Internet???????

• ??
• 1969 ARPANet??
• 1972 ???ARPANet???????????
• 1978 ???TCP?????????????--IP
• 1982 ??TCP/IP?????ARPANet
• 1986 NSFNet??
• 1989 ???HTML/HTTP
• 1993 ?????????Mosaic
• 1995 NSFNet??,Internet??????

4

• Internet???
• 1987 ????????????????????,????
• 1994 NCFC????SPRINT????Internet?64K??????,????Int
  ernet??????,????????????Internet???????????ChinaN
  et????????????CERNet??????
• 1995 ?????????????????Internet????????????ChinaN
  et?????CERNet?????,??108???
• 1996 ChinaNet?????????????????(169?)????
• 1997 ??????????CNNIC??ChinaNet????CERNet????????
  ????????1997??????????62?
• ??2001?6?????????2650?

5
Commercialization
Privatization
Interoperable
21st Century
High Performance
Networking
SprintLink
Research Education
InternetMCI
Networks
US Govt
Networks
ANS
ARPAnet
NSFNET
Active
gigabit
Nets
testbeds
wireless
Internet2, Abilene, vBNS
WDM
Advanced US Govt Networks
Quality of Service
(QoS)
Research and
Development
Partnerships
6
????????????
7
(No Transcript)
8
CERNet?????????
Cernet
Cernet
155Mbps
155Mbps
Cisco 6509
1Gbps
100Mbps
9
CERNET ???
10
??Internet?????
11
????

• Internet?????????
• OSI???? vs. TCP/IP???
• ???????? vs. ???
• IP?????????????????
• ????DNS?HTTP?FTP?E-mail
• ??????????
• ????
• ????????

12
??????(OSI)????
7 6 5 4 3 2 1
Application ???
Presentation ???
Session ???
Transport ???
Network ???
Data Link ?????
Physical ???
13
Internet TCP/IP

• TCP/IP?????????????(Interconnection)
• 70????ARPA????
• TCP/IP?????????RFC??
• TCP/IP?UNIX??
• TCP/IP?????????
• TCP/IP???????

14
TCP/IP??? vs. OSI????
4
3
2
1
15
TCP/IP?????

• TCP Transmission Control Protocol
• UDP User Datagram Protocol
• ?????????,???????
• ??????

TCP??????????????? UDP????????????????
16
TCP/IP?????

• IP Internet Protocol
• ICMP Internet Control Message Protocol
• ARP Address Resolution Protocol
• RARP Reverse Address Resolution Protocol
• ???(IP)???,??????????????

IP - ???????????? ICMP - ???????/????????????????
ARP - IP??????????(MAP) RARP - ?????IP?????
17
?????

• ?IP?????????????????

???

• ????CSMA/CD??
• ????????

18
TCP/IP????

• Telnet Remote login
• FTP File Transfer Protocol
• SMTP Simple Mail Transfer Protocol
• DNS Domain Name System

19
TCP/IP Architecture
ftp protocol
ftp client
ftp server
TCP protocol
TCP
TCP
IP protocol
IP protocol
IP
IP
IP
e protocol
f protocol
ethernet driver
FDDI driver
ethernet driver
FDDI driver
ethernet
FDDI
20
????

• Internet?????????
• OSI???? vs. TCP/IP???
• ???????? vs. ???
• IP?????????????????
• ????DNS?HTTP?FTP?E-mail
• ??????????
• ????
• ????????

21
?????

• 1975 - Xerox ?Standford????????
• 1980 - DEC,Intel, Xerox????????????????????
• 1982 - ?????V2.0????
• 1987 - IEEE??????????,10BASE-T
• 1995 -??100BASE-TX(?????)??

22
???????

• ???-?????????
• 10BASE5(??),10BASE2(??)
• ????-?????????
• 10BASE-T,10BASE-F,100BASE-Tx,100BASE-Fx,1000BASE-T
  ,1000BASE-SX,1000BASE-LX,1000BASE-ZX

23
??????

• ????????OSI??????
• ??Cat 3????????
• RJ45-8???????
• ???????100?
• ??????????-????
• ??????????

24
??? - ???
Application
Presentation
Session
Transport
Network
Data Link
Physical
Repeater
???????????(Hub)
25
??????
A
100?
100?
Repeater
100?
Repeater
100?
Repeater
B
100?
Repeater
26
??? - ?????(HUB)
HUB(functional)
????
??? ??
............
???
???
???
???
????
RJ45??
UTP??
27
10Base-T(UTP)
RJ-45 ???UTP?? ? ?? 1(?/??)
??,?2? 2(??) ??- 3(?/?) ??
?3? 6(?) ??- T568B ??/???????
Hub
????(??100?)
28
10BASE-T UTP
????????500?
??Hubs
??4?????(hops)
???Hub? ???100?
??1024??/??
10 Mbps
29
100BASE-T ?????
???????205?(???400?)
??Hubs
??2?????
???Hub? ???100?
??1024??/??
100Mbps?10Mbps????
30
????? - Ethernet
????????????????(CSMA/CD)
?
101100....1001
10 Mbps
NIC
IEEE802.3
?????????
31
CSMA/CD????(????????/?????)

• ?????????????????
• ?????????????????
• ???????,???????????
• ??????????????,??????
• ????
• ??????????????????,??????
• ?????????
• ?????,???????????????????
• ?????
• ??????????16?

32
CSMA/CD-??
A?????
??
??
101010........
??? ??? 9.6us?
No
A
B
Yes
??
33
CSMA/CD-????
??????? ??????? ?????
Collision!!!
34
CSMA/CD???

• ??
• ??????????90
• ??
• ???????
• ??????????????

35
802.3??????(MAC)???
?????
?????
FCS Frame Check Sequence SFD Start Frame
Delimiter PAD Filling bytes
????
?????
???
??
??
??
Source Address
Destination Address
DATA (transparent)
FCS
Preamble
SFD
PAD
Length
7 1 6
6 2 45 1500
0n 4
??1518????64??
?? ????????????????
36
????(MAC Address)

• ??????
• ????(Broadcast)
• ????(Multicast)

00804000003c
????
Address Lists - Manufacturing - Symbolic
(FLUKE_00003c)
????
Mfg. list Fluke 008040 IBM 08005a
etc.
37
????(Link Pulse)

• ??????HUB???
• ???????HUB????????
• ??HUB?150ms????????????????

38
??(Collisions)

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

B
A
39
???(Utilization)

• ?????????????
• ??????????
• ?????????????????
• ????????????
• ?????????????
• ????????????????
• ?????????40

40
??(Broadcast)

• ?????????
• ?????????
• ????????,?????
• ???????????????????
• ?????????5

41
??????????

• ??(Jabbers)
• ??????1518???/FCS??????????
• ????????(FCS)
• ?????FCS????
• ??(Short Frame)
• FCS?????????64???
• ???(Runts)
• ??????????????????
• ????(Late Collision)
• ????64???????
• ????(Remote Collision)
• ?????????????
• ????(Local Collision)
• ??????????????
• ??(Ghosts)
• ?????????????????????

??????? ???????
42
????? ??(???)
Application
Application
Presentation
Presentation
Session
Session
Transport
Transport
Network
Network
Data Link
Data Link
Bridge Switch
Physical
Physical
Repeater
???????,???????
43
????? ??
??????
??2
??1
BRIDGE
2
1
C
A
B
D
E
F
A on 1 D on 2 E on 2 B on
1 LM on 1 ,,,,,
?????????, ?????????? ?????????
A???B,????
1
B???D,?????
2
44
????????
10Mbps
10Mbps
10Mbps
10Mbps
10Mbps
10Mbps
10Mbps
port MAC add port 1 0800234 port 2
097AC45 port 3 097B3A8 ...... ...... port 10
4AB67D
10Mbps
45
??????????

• ????(Store Forward)
• ??????????????
• ??(Cut Through)
• ???????????????????
• ?????(Modified Cut Through)
• ????64??????????

46
????
????1)????????????2)???????

• ????1)???2)???????

???????1)???2)???????? (???????)
47
??????

• Initial MAC address table is empty.

48
??MAC??

• Station A sends a frame to station C.
• Switch caches the MAC address of station A to
  port E0 by learning the source address of data
  frames.
• The frame from station A to station C is flooded
  out to all ports except port E0 (unknown unicasts
  are flooded).

49
??MAC??

• Station D sends a frame to station C.
• Switch caches the MAC address of station D to
  port E3 by learning the source address of data
  frames.
• The frame from station D to station C is flooded
  out to all ports except port E3 (unknown unicasts
  are flooded).

50
??? Filtering Frames

• Station A sends a frame to station C.
• Destination is known frame is not flooded.

51
Filtering Frames (Cont.)

• Station A sends a frame to station B.
• The switch has the address for station B in the
  MAC address table.

52
Broadcast and Multicast Frames

• Station D sends a broadcast or multicast frame.
• Broadcast and multicast frames are flooded to all
  ports other than the originating port.

53
VLAN ?????

• Segmentation
• Flexibility
• Security

A VLAN A Broadcast Domain Logical Network
(Subnet)
54
VLAN ??

• Each logical VLAN is like a separate physical
  bridge.
• VLANs can span across multiple switches.
• Trunks carry traffic for multiple VLANs.
• Trunks use special encapsulation to distinguish
  between different VLANs.

55
VLAN Membership Modes
56
802.1Q Trunking
57
802.1Q Frame
58
ISL Tagging
ISL trunks enable VLANs across a backbone.

• Performed with ASIC
• Not intrusive to client stations ISL header not
  seen by client
• Effective between switches, and between routers
  and switches

59
ISL Encapsulation
60
VTP Protocol Features

• ??VLAN??????

61
VTP Modes

• Creates VLANs
• Modifies VLANs
• Deletes VLANs
• Sends/forwards advertisements
• Synchronizes
• Saved in NVRAM

• Creates VLANs
• Modifies VLANs
• Deletes VLANs
• Forwards advertisements
• Does not synchronize
• Saved in NVRAM

• Forwards advertisements
• Synchronizes
• Not saved in NVRAM

62
VTP Operation

• VTP advertisements are sent as multicast frames.
• VTP servers and clients are synchronized to the
  latest revision number.
• VTP advertisements are sent every 5 minutes or
  when there is a change.

63
????
Switched ????
Permanent ????
64
xDSL ???????
8 Mbps downstream
PSTN
768 Kbps upstream
Public Switched Telephone Network
6.1 Mbps downstream
TV
Network Switch, Video Program Sources, etc..
ATM
640 Kbps upstream
ADSL MODEM
ADSL MODEM
PS
PS
PC
ENet
4.1 Mbps downstream
384 Kbps upstream
1.5 Mbps downstream
64 Kbps upstream
65
????

• Internet?????????
• OSI???? vs. TCP/IP???
• ???????? vs. ???
• IP?????????????????
• ????DNS?HTTP?FTP?E-mail
• ??????????
• ????
• ????????

66
IP??
67
?????IP??

• ?0?????,???????????????????
• ?1??????
• ?0?????,????IP??????????
• ?1?????,??????,????????????????
• ?0?IP??,?0.0.0.0?
• ?????127.X.X.X.,??X.X.X??????????????????????(Loop
  back test)???
• ?1??255.255.255.255,??????????????????????0.0.0.
  0?
• ????
• 10.0.0.0 - 10.255.255.255
• 172.16.0.0 - 172.31.255.255
• 192.168.0.0 - 192.168.255.255

68
IP??????

• IP??????????????????,???????????,IP???????????????
  ?????
• ????????????????(??????????????),???????????????IP
  ??,?????net-id????,???????????(multihomed host).
• ??Internet???,?????????????????????????,??????????
  ???????net-id.
• ?IP???,?????????net-id???(????????????????)??????
  

69
IP?????
70
IP?????
71
Addressing Without Subnets
???????????,????????,????????
72
????
73
Subnet Addressing
74
Subnet Mask ????
75
Decimal Equivalents of Bit Patterns
76
??????

• Subnets not in usethe default

77
??????

• Network number extended by eight bits

78
??????

• Network number extended by ten bits

79
ARP(Address Resolve Protocol)??????

• ?????????MAC??
• ?????????ARP??,??????????????ARP??,????????MAC??,?
  ????????????IP???MAC???????ARP?,??????IP??????????
  ?????
• ??????IP??,??????????????????,???,???ARP??????MAC?
  ?,???????????,????????MAC??,????????,????????????
  ????????

80
TCP/IP - ????
Amanders . sales.fluke.nl
Domain Name ??
Host Name
Network Name
Domain Name System Query ????
194.220.133.60
IP Address IP??
Host Address
Network Address
Address Resolution Protocol Query ??????
MAC Address ????
00C017 850022
81
Variable-Length Subnet Mask???????

• Subnet 172.16.14.0/24 is divided into smaller
  subnets
• Subnet with one mask (/27)
• Then further subnet one of the unused /27 subnets
  into multiple /30 subnets

82
VLSM???????
83
VLSM Example
84
Route Summarization????

• Routing protocols can summarize addresses of
  several networks into one address
• CIDR(Classless InterDomain Routing) ??????

85
Summarizing Within an Octet
86
VLSM??????
192.16.5.33 /32        Host 192.16.5.32 /27 Subnet
192.16.5.0 /24 Network 192.16.0.0 /16 Block of
Networks 0.0.0.0 /0 Default

• Supports host-specific routes, blocks of
  networks, default routes
• Routers use the longest match

87
??

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

88
???

• Routers must learn destinations that are not
  directly connected.

89
???? vs. ????

• Dynamic Route????
• ????????????????????????

• Static Route????
• ?????????

90
Static Route Example

• This is a unidirectional route. You must have a
  route configured in the opposite direction.

91
Default Routes ????

• This route allows the stub network to reach all
  unknown networks beyond router A.

92
????

• ??????
• ?????

93
Routing Protocols

• ??????????????????????????????????????
• ?????? ?????(AS)??????,????????BGP(Border
  Gateway Protocol )?
• ?????? ?????????,??
• RIP (Routing Information Protocol)
• IGRP (Interior Gateway Routing Protocol)
• EIGRP (Enhanced Interior Gateway Routing
  Protocol)
• OSPF (Open Shortest Path First)

94
Autonomous Systems Interior or Exterior Routing
Protocols

• An autonomous system is a collection of networks
  under a common administrative domain.
• IGPs operate within an autonomous system.
• EGPs connect different autonomous systems.

95
????????????

• ???????????,??bit??

96
????????????

• ??????????

97
????????????

• ????????????,????????IP??

98
????????????

• ????????????

Routing Table S 198.150.11.160/27 via
198.150.11.66 C 198.150.11.32/27 via e0 C
198.150.11.64/27 via s0
99
????????????

• ????PPP??,?????????????

100
????????????

• ??????????????????,??????????????

101
???,???,???
Router
Switch
Hub
102
???/???

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

103
??/???

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

104
???

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

105
ICMP(Internet Control Messages Protocol)

• IP????????????
• ICMP????????????,???????
• ICMP????????????

106
?????

• ICMP????????
• ????????????????
• ????/??(ping)
• ????
• ??????????
• ?????????
• ???????
• ???????

107
ACL(Access Control List)??????

• ACLs??????????????????????????????

108
ACL??

• ??ACL??????,???????
• ??????????
• ????????
• ??????????
• ACL??????????????????ACL???????
• ???????????????????
• ???????????????,?FTP,HTTP??

109
ACL??

• ACL??????????????????????????????????,Cisco?IOS??,
  ??ACL????????????????????????????????????????,????
  ??????????
• ??????????,?????????Routed Protocols??ACL???????,?
  ?????ACL??????????????inbound,??????????????outbo
  und?

110
Inbound or Outbound

• Inbound or Outbound
• ??????Inbound,??????outbound

111
ACL?????
112
ACL???

• ????ACL????
• Router(config) access-list
  access_list_number permitdeny
  test_conditions
• ???????????
• Router(config-if) protocol access-group
  access_list_number
• ????????
• Router(config) no access-list
  access_list_number

113
ACL?????

• ACL??????????????????,??????????????
• ?????????ACL???,????????
• ???????????ACL,????????????,?????ACL???,??????????
  ????????

114
??ACL

• ??ACL
• ?????
• ?????????????
• ??ACL(??1?99),???????????????????????????ACL??????
  ???IP???

115
??ACL??

• ???????access-list??????????????????ACL???????????
  ????
• Router(config) access-list access-list-number
  deny permit source source-wildcard
• ??access-list 1 permit 172.16.0.0 0.0.255.255
• ???????no??,????????ACL????
• Router(config) no access-list access-list-number
  
• ??no access-list 1

116
??ACL??

• ????????,????ACL????
• ??1E0?E1??????????172.16.0.0???????,????????
• ??2E0????????????172.16.4.13????,???????????
• ??3E0????????????172.16.4.0???,?????????

117
??1??????????

• E0?E1??????????172.16.0.0???????,????????
• ???ACL???permit??????????????,????0.0.255.255???
  ????IP???????(?16?)?
• ???ACL?????E0?E1?

118
??2???????????

• E0????????????172.16.4.13????,???????????
• ???ACL???deny??????????????,????0.0.0.0?????????
  ???????
• ???ACL???,0.0.0.0 255.255.255.255IP?????????,???
  ????????????????,???????any???
• ???ACL?????E0?

119
??3???????????

• E0?????????????172.16.4.0???,?????????
• ???ACL???deny????172.16.4.0??????,????0.0.0.255,
  ???????IP??????????????????????1,??????IP????????
• ???ACL????????????????????IP???
• ???ACL?????E0?

120
??ACL

• ??ACL
• ??????????
• ????????????
• ????????????,????ACL???ACL??????????,??TCP?UDP????
  ???????ACL?????????????
• ??ACL????????100-199?

121
??ACL??

• ????????,????ACL????
• ??1?E0??,??????172.16.4.0???FTP????172.16.3.0??,?
  ??????????
• ??2?E0??,??????172.16.4.0??? Telnet
  ???,???????????

122
??1????FTP??

• ?E0??,??????172.16.4.0???FTP????172.16.3.0??,?????
  ??????
• ???ACL???deny????172.16.4.0???FTP-DATA(port20)?
  ???172.16.3.0???
• ???ACL???deny????172.16.4.0???FTP(port21)????17
  2.16.3.0???
• ???ACL?????????????
• ????ACL101?????E0?

123
??2????Telnet ??

• ?E0??,??????172.16.4.0??? Telnet ???,???????????
• ???ACL???deny????172.16.4.0???Telnet(port23)???
  ?
• ???ACL?????????????
• ????ACL101?????E0?

124
????

• ????(wildcard mask)???4???32bit???????IP??????,???
  ?0/1,????????IP????????
• ???????0,??????bit???
• ???????1,?????(??)??????
• ACL???????????????????"??"??"??"???IP???

125
???? vs. ????

• ????32?,??????????????????,0/1???????IP???????????
  ???????????,0/1??ACL????????IP????????
• ??
• 172.16.4.0 0.0.0.255
• 172.16.4.0 255.255.255.0

126
?????????
127
??????

• ????B???,?8??????????????,?????????171.30.16.0171
  .30.31.0?????????

128
??????

• ????B???,?8??????????????,?????????171.30.16.0171
  .30.31.0?????????
• ??,????????(171.30),??????????????0?????????????,?
  ?????????????1?
• ?????????????15 (00001111)?
• ??????????0.0.15.255,?????171.30.16.0?171.30.31.0?
  IP???

129
??????

• IP?????????16 (00010000)???????????0,????????IP???
  ???(0001)???????????,???????16 (00010000)?31
  (00011111)??????,?????????1?

130
any??

• ???????????????,????????,????0.0.0.0???ACL?????,??
  ???255.255.255.255?????????,???????????
• Router(config) access-list 1 permit 0.0.0.0
  255.255.255.255
• ???
• Router(config) access-list 1 permit any

131
host??

• ????IP????????,Cisco IOS???????ACL????????
• ?????????IP??,?ACL???????????????????,???????(?171
  .30.16.29)???,????ACL???????????,??????????????0(?
  0.0.0.0)?????????????????
• Router(config) access-list 1 permit 171.30.16.29
  0.0.0.0
• ???
• Router(config) access-list 1 permit host
  171.30.16.29

132
??ACL

• ??show interface
• ???????????????ACL
• ??show running-config
• ??ACL?????????
• ??show access-list
• ?????ACL????

133
ACL???

• ACL?????????,?????????????ACL?????,???????????????
  ????,???????,?????????????????
• ACL???????????ACL???????????????ACL????????,?????
  ??ACL?????????????

134
Network Address Translation

• An IP address is either local or global.
• Local IP addresses are seen in the inside network.

135
Port Address Translation
136
Translating Inside Source Addresses
137
Configuring Static Translation
Router(config)ip nat inside source static
local-ip global-ip

• Establishes static translation between an inside
  local address and an inside global address

Router(config-if)ip nat inside

• Marks the interface as connected to the inside

Router(config-if)ip nat outside

• Marks the interface as connected to the outside

138
Enabling Static NAT Address Mapping Example
139
Configuring Dynamic Translation
Router(config)ip nat pool name start-ip end-ip
netmask netmask prefix-length prefix-length

• Defines a pool of global addresses to be
  allocated as needed

Router(config)access-list access-list-number
permit source source-wildcard

• Defines a standard IP access list permitting
  those inside local addresses that are to be
  translated

Router(config)ip nat inside source list
access-list-number pool name

• Establishes dynamic source translation,
  specifying the access list defined in the prior
  step

140
Dynamic Address Translation Example
141
Overloading an Inside Global Address
142
Configuring Overloading
Router(config)access-list access-list-number
permit source source-wildcard

• Defines a standard IP access list permitting
  those inside local addresses that are to be
  translated

Router(config)ip nat inside source list
access-list-number interface interface overload

• Establishes dynamic source translation,
  specifying the access list defined in the prior
  step

143
Overloading an Inside Global Address Example
144
????

• Internet?????????
• OSI???? vs. TCP/IP???
• ???????? vs. ???
• IP?????????????????
• ????DNS?HTTP?FTP?E-mail
• ??????????
• ????
• ????????

145
Internet????

• WWW(World Wide Web)???
• Web Application / Web Service
• E-mail(Electronic Mail)????
• Mailing List ???
• FTP(File Transfer Protocol)????
• Telnet ????
• Remote Desktop ????
• NEWS ????
• BBS(Bulletin Board System)?????
• VOD(Video on Demand)????
• Video Conference ????
• E-commerce ????
• B2B (Business to Business) ?????
• B2C (Business to Customer) ??????

146

• P2P (Peer to Peer) ?????
• ????
• BitTorrent / eDonkey / Guntella / KaZaA /
  FastTrack
• ?????
• SETI_at_HOME / Folding_at_HOME
• ??
• Instant Message (IM) ????
• MSN Messenger / AIM /Yahoo! Messenger / ??QQ /
  jabber
• Blog ????(Weblog)
• ?E-mail?BBS?ICQ??????????????
• Blogger ??
• www.blogger.com / www.cnblog.com /
  www.blogchina.com
• SNS (Social Network Service) / SS (Social
  Software) ?????
• Wiki
• ?????????,????????,??????????,??????????????????
• zh.Wikipedia.org ????
• ??????????????(killer application)?

147
DNS (Domain Name System)

• ????????IP???????
• ???
• ex www.hebtu.edu.cn
• ?????
• ???????
• ???edu?com?org?gov?net?mil?ca?fr?de?cn
• ???edu?com?gov?ac?net(cn ?)
• ???pku?tsinghua?hebtu(edu.cn?)
• DNS???
• ????????????,????
• ??????????????

148
????
?
Query
a.root-server.net
Ans.cn
?
Name Server
?
Query
ns.cn
Query www.pku.edu.cn
Ans.edu.cn
?
Query
Answer 162.105.9.73
ns.edu.cn
Ans.pku.edu.cn
?
?
?
Query
ns.pku.edu.cn
Answer 162.105.9.73
www.pku.edu.cn 162.105.9.73
149
WWW

• ????
• HTML(Hyper Text Markup Language)
• HTTP(Hyper Text Transfer Protocol)
• ???(WWW/Web Server)
• IIS?PWS?Apache?
• ???
• IE?Mozilla?Opera?Lynx?
• URL(Uniform Resource Locator)
• ex http//www.hebtu.edu.cn/index.html
• ??http?ftp?news?telnet?
• ???IP??/???
• ?????????

150

• ?????(Proxy Server)

• ?????
• ????

Cache Server(??)
151
FTP

• ????
• ???
• IIS?Wu-ftpd?Serv-U?ProFTPD...
• ????
• IE?DLExpert?CuteFTP?FlashGET?FlashFXP
• ??(Upload)???(Download)
• ????????
• ????
• ???anonymous
• ??e-mail address

152

• IE
• ????
• ftp//ftp.hebtu.edu.cn/pub/Linux/
• ?????
• ftp//usernamepassword_at_hostname/path
• CuteFTP
• FlashGET
• ?????(MultiThread)
• ???????????????,????????
• ????

153
????FTP??(PORT mode)
FTP Client
FTP Server
20 ??
21 ??
5050
5051
PORT 5051
OK
????
OK
154
????FTP??(PASV mode)
FTP Client
FTP Server
20 ??
21 ??
5050
5051
PASV
3267
OK 3267
????
OK
155
E-mail

• ????
• ??????????
• SMTP Server(Simple Mail Transfer Protocol)
• POP3 Server(PostOffice Protocol Ver.3)
• ????(User Agent)??????????
• Outlook Express?Eudura?Foxmail
• WebMail
• ??(mailbox)
• username_at_hostname
• webmaster_at_hebtu.edu.cn

156
Mail Router/ Transfer Agent
Write Mail Send Mail
Read Mail
157
P2P??

• Peer-to-Peer File Sharing
• BitTorrent
• eDonkey
• Gnutella
• KaZaA
• FastTrack
• ??
• ???????
• ??????????
• ???? ? ????

158

• BitTorrent
• ??A WebSite?.torrent???tracker?peers ( leechers
  ?seeds )
• .torrent??????tracker?IP??
• Client?tracker???peers??,??peer set
• ??????????(chunk)?peer set???
• ??
• tit-for-tat ????,????
• Peer????????best downloader/uploader??
• BT??
• http//www.btchina.net
• ?????BitTorrent / BitComet

159
????

• Internet?????????
• OSI???? vs. TCP/IP???
• ???????? vs. ???
• IP?????????????????
• ????DNS?HTTP?FTP?E-mail
• ??????????
• ????
• ????????

160
???????
Vertical Cable ????
Horizontal Cable ????
Building Cable ?????
161
?????????(Link)
PATCH CORD
HUB
??
PATCH CORD
????
???
???
???
???
162
Types of LAN Cable???????

• Unshielded Twisted Pair ??????(UTP)
• Shielded Twisted Pair ?????(STP/ScTP)
• Coax Cable ???
• Fiber-optic Cable ??

UTP/STP Cat 3, 4, 5 or ISO Class A, B, C, D New
Enhanced Cat 5, Cat 6, Cat 7, Class E, Class
F? Fiber Single mode (??) and multi mode (??)
163
STP or UTP????? - ??????

• High performance depends on the quality of
  Installation
• ???????????
• Proper bonding of shield is very important.
• ??????????????
• Grounding is very important ???????
• No suitable method for field certification test
• ???????????

UTP or STP ?
164
????????????

• ???????????
• ??????????
• ???5???????????????
• ?????????????(?????)
• ???????????
• ?????????
• ???????
• ?????
• ??????

165
??-- ?????????
?????
166
?????????

• ?????
• ????
• ??, ??, ??
• ??
• ????(NEXT)
• ??(?????)
• ??
• ??????
• ?????

167
???????
???????????

• ????(???????)
• ????
• ??(??)

168
?????????

• ????????????????
• ????(??????????)
• ????????,??,????,???????

169
????????

• ANSI/EIA/TIA568-A??????
• ?????????
• ????????????????
• TSB-67 ???????????????????
• ISO11801????????
• ???????????!

170
TSB-67

• Transmission Performance Specifications forField
  Testing of UTP Cabling Systems
• ????UTP???????????
• Prepared byANSI/EIA/TIA PN-3287Task Group on
  UTP Link Performance

171
UTP????-TSB-67

• ????????
• ??????EIA/TIA-568-A????
• ?????UTP????
• ??????????????
• ??Real World-???????

172
????Channel-??(????????)
????
????
?????? Patch Cable
?????? Patch Cable
????
????
???
?????????
????
???
173
????Basic Link-????(????????)
????
????
????
???
????
??????? Patch Cable
??????? Patch Cable
????
???
174
???????

• ????????????
• ????
• ??????????
• ??????????????????????
• ?????????
• ???????
• ???????
• ??????
• MUTO-Multi-user Telecommunication Outlet
• ???????
• CP-Consolidation Point ?????

Defined by TSB75 ?TSB75???
175
???????MUTO????

• ???????
• ??????????
• ???????

MUTO - ???????
Horizontal Cross-Connect
Workstation
Workstation
. . . .
Workstation
Equipment
Workstation
176
?????????CP????

• ??????????
• ????????????
• ???????

CP - ?????(???)
Horizontal Cross-Connect
Workstation
Workstation
Workstation
Workstation
Workstation
Workstation
177
????

• ?????????????
• ??10BASE-T, 100BASE-TX
• 10 10Mbps
• 100 100Mbps
• BASE ????(BASE BAND)
• T ???(Twisted Pair)

178
????

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

179
??????
0
1
0
0
1
1
0
1
0
0
NRZ
Man

• Diff.Man

180
High Speed LAN Cable - UTP????-UTP
Type Bit Rate Pair Used
Max. Freq

• 10BaseT 10Mbps 2 10MHz
• 100BaseT4 100Mbps 4 25MHz
• 100BaseTX 100M bps 2 80MHz
• 100VG AnyLAN 100Mbps 4 15MHz
• ATM155 155Mbps 2 80MHz
• 1Gbps 1Gbps 4 100Mz

?
Bit Rate Frequency
??????????????????!
181
????

• MHz ??? Mbps
• MHz ?????
• ???????
• ??????
• Mbps ????
• ????????(??,??,??)
• ??OSI??

182
????
Time Domain ??
Frequency Domain ??
1
Freq. (MHz)
Period
183
????
Time Domain ??
Frequency Domain ??
1
3
Freq. (MHz)
184
????
Time Domain ??
Frequency Domain ??
1
3
5
7
Freq. (MHz)
185
????
NRZ?????
??
??
0
Freq. (MHz)
186
????

• ?????????????????????
• ???????Mbps ???????
• ???????MHz
• ???????
• ???????
• ??????
• ??????4KHz
• Modem??14.4K,33.6K,56Kbps

187
Field Test Parameters???????
Cat 5 ????????

• Wire Map-???(??/??/??/??)
• Length-??
• Attenuation-??
• NEXT-????
• ACR-????? (ISO11801)
• Return Loss-???? (ISO11801)

188
Field Test Parameters???????

• Wire Map???(??/??/??/??)
• Length??
• Attenuation??
• NEXT????
• Propagation Delay????
• Delay Skew ???
• PS NEXT ??????
• Return Loss ????
• EL FEXT ??????
• PS ELFEXT????????

Cat 5n ????????
Cat 5E ????????
?????? ????????
189
Wire Map ???

• ?????
• ??
• ??
• ??
• ??
• ??(Split pairs)
• ??...

190
??????? - T568A
1 2 3 4 5 6 7 8
191
??????? - T568B
1 2 3 4 5 6 7 8
192
????
193
??
194
??/??
T568A?T568B ??
195
??(Split Pairs )

• ?????????????
• ?????????(NEXT)

196
????????

• ???????
• ?????EMI?RF??
• ??????
• ????????
• ???????????
• ????

197
??
??Jacket (Typically PVC)
Strengthening Material (Aramid Yarn) ????
Buffer ??
Cladding ???
Core ?
198
?????
ST ??
SC ??
199
????

• ????(SC,ST,FC,LC)
• ?????
• ?????

200
???????

• ????
• ?????,???????????
• ???,??????,?????(??30??)
• ?1300?1550nm???
• ????
• ?????,???????????
• ???,????LED??,?????,?????????(??100?)
• ?850?1300nm???

201
??
Core
Cladding
Singlemode
9/125 micron
Multimode
62.5/125 micron
202
????????
Backbone Cabling
Horizontal Cabling
203
?? Wireless

• ?? ??,????
• ?? ????,????,?????

204
??LAN??

• 802.11b11M,2.4GHZ
• 802.11a54M,5GHZ
• 802.11g54M,???802.11b

205
????
206
??LAN??

• ??LAN????????????????
• ??LAN????????/????(CSMA/CA)

207
??LAN????

• ??LAN????????????
• ??????SSID(???????)???????????
• ?????????????????

208
WEP

• ??????(WEP)?802.11????????????,???????????????????
  ??????????
• ????
• ??????WEP??????????????
• ????WEP??????????WEP??????????
• WEP??RC4???,???????????,????????????

209
????

• Internet?????????
• OSI???? vs. TCP/IP???
• ???????? vs. ???
• IP?????????????????
• ????DNS?HTTP?FTP?E-mail
• ??????????
• ????
• ????????

210
?????SNMP ??

• ?????????????????
• ??-???(Managers)
• ??????????
• ??SNMP??????(Agents)
• ??MIB????
• ??-??(Agents)
• ??????
• ????SNMP????MIB??

SNMP - Simple Network Management
Protocol ????????
211
??? - SNMP ??? (SNMP-????????)
MIB
???,????, ????
CONTROL
AGENT
???
SET
GET
SNMP compliant
???
SNMP compliant
MIB-?????
212
Network Management????
Intelligent HUB (MIB)

• ??????????MIBs?
• ???????????
• ??SNMP??

SNMP
Intelligent Router (MIB)
Management Station
213
????????(SNMP)

• ??????
• GET(????)
• GETNEXT(???????)
• SET(???)
• TRAP (??????????)

????

• ????
• System Group(?????)
• Interface Group(???)
• IP Address Group(IP???)
• Ethernet Interfaces(?????)
• Token Ring Interfaces(?????)
• Remote Monitoring (RMON)(????)

????
214
??????

• The SNMP Community String
• SNMP ?????
• Usually Public but should be changed during
  configuration
• ?????Public,?????????
• If this is wrong, we will not get any response
• ???????????????

215
?????(MIBs)

• MIB?????????,???????
• MIB???????????????
• ????,IP????
• ???MIBs??????
• ?????????????? MIBs?????????

216
MIB??
Root
CCITT(0)
ISO(1)
JOINT-ISO-CCITT(2)
ORG(3)
SNMP OBJECT1.3.6.1.2.1.11
DOD(6)
INTERNET(1)
DIRECTORY(1)
MGMT(2)
EXPERIMENTAL(3)
PRIVATE(4)
MIB(1)
SNMP(11)
TRANSMISSION(10)
SYSTEM(1)
OIM(9)
EGP(8)
INTERFACES(2)
UDP(7)
ADDRESS TRANSLATION(3)
TCP(6)
ICMP(5)
IP(4)
217
?????MIBs

• System Group
• Interface Group
• IP Address Group
• Ethernet Interfaces
• Token Ring Interfaces
• Remote Monitoring (RMON)

218
????(RMON)

• RMON??9?(Ethernet)
• ???????????????RMON??
• Statistics
• History
• Alarm
• Hosts
• Matrix
• Filter
• Capture
• Event

219
?????????

• ??????(Network topology )
• ???????(Cable routing and label )
• ???(Address map - MAC, IP, IPX... )
• ?????(Server configuration)
• ????(Client configuration )
• ???????(Network Utilization statistics )
• ??????????
• ???(Default Routing table)
• ??????(Network Software configuration )
• ........ ??

220
???????????

• ???????(?????)?????
• ???,??????
• ????????????
• ???????
• ?????????
• ?????????????
• ??????????

221
?????????

• ??????
• ??????????
• ????????
• ??????
• ?????
• ???????
• ???????
• ???????
• ?????????????????
• ????????????????????
• ????
• ????????(????????)

222
????

• Internet?????????
• OSI???? vs. TCP/IP???
• ???????? vs. ???
• IP?????????????????
• ????DNS?HTTP?FTP?E-mail
• ??????????
• ????
• ????????

223
(No Transcript)
224
?????????????????
??????? ???? ???? ???? ????
??? ????
??? ????????
??? ?????
Cisco 6509
???? ????? ?????
??? ??? ???????
????? ????
??? ????
??? ????
????
??? ???? ???
???? ???? ???? ???? ????
??? ????
????
?????
???? ?????? ????????
???? ???? ???
??? ???
?????
225
??????????????????
???
????
?????
????
??? ???
???
??? ???
???
????? ???? ????
Cisco 6509
???
????
?????
?????(?)
?????
?????
?????
?????
???
?????
226
??????????????????
Cisco 3550-12T
????
????
????
?????
??
?????
1??
???
227
??????????????????
Cisco 3550-12T
???
?????
???
???
?????
228
????
????
??
????
????
????

• ????????,????
• ????????????????????????????????
• Eg ????,
• 202.206.96.0,202.206.96.1,255.255.255.0,202.206.96
  .2254,202.206.96.255
• ?????256 - ???????? - 3
• ???????????????ip??

229
IP????

• ?????????????????????TCP/IP??

230
??????????
231
?????ping(202.206.97.10)

• ?????
• C\gt ping 202.206.97.10 OK
• ?????/???????
• C\gt ping 202.206.97.20 OK
• ?????/???????
• C\gt ping 202.206.97.30 OK
• ??
• C\gt ping 202.206.97.1 OK
• ???????
• C\gt ping www.hebtu.edu.cn OK
• IE????Internet??????????????????? OK
• ????

232
?????????????

• ???????
• ???????????
• ?????
• ????????
• ????
• ??????????
• ??1000Mbps
• Cisco 6509????720Gbps
• 3?????400Mpps
• ???????????

233
???????????
24??
1?
1?
????????????????????????????
234
?????
????
????
?????
????
235
11.28??????(?/?)
236
?????(ICMP???)
IPaddr flows octets
packets 202.206.101.18 229261
21092380 229265 ----
255f/s 202.206.96.137 145409
13879140 150861 211.82.247.46
74410 6845720
74410 202.206.110.6 73067
6722164 73067 202.206.109.165
67802 6237784
67802 202.206.103.206 67622
6221224 67622 211.82.240.38
67551 6214620
67551 202.206.109.164 67193
6181756 67193 211.82.240.243
66417 6110364
66417 202.206.109.189 66172
6087824 66172 ----
73f/s ??? 220????gt1f/s,?????????
237
?????(TCP/135???)
IPaddr flows octets
packets 202.206.97.15 12548
603840 12580 ----
14f/s 202.206.105.114 9645
699648 14576 202.206.109.64 8395
498720
10390 202.206.110.45 6631
327648 6826 202.206.105.132 6625
330240
6880 202.206.111.200 6601
317664 6618 202.206.109.58 5422
260256
5422 202.206.111.205 5086
357744 7453 202.206.111.189 3776
387024
8063 202.206.111.180 3607
351024 7313 ---- 4f/s ????
202.206.101.18 236809 22416994
247754 ---- 263f/s 202.206.96.137
147861 15644446
166086 211.82.247.46 74412
6845950 74415 202.206.110.6
73070 6722578
73076 202.206.105.132 70585
6216461 70876 202.206.109.165
67860 6250739
67957 202.206.103.206 67622
6221224 67622 211.82.240.38
67615 6223120
67718 202.206.109.164 67508
6272715 68335 202.206.97.15
66803 5595300 66835
---- 74f/s
238
11.28??????(?/?)
239
11.28??????(Mbps)
240
11.28??????(Mbps)
241
??????????????????

• ??????
• Red Code?Nimda?Slammer?Blaster?Nachi?Sobig.F?
• ??????
• ??????
• ???????????,?ICMP,TCP/135,TCP/449?
• ?????
• ?????????????
• ????
• ??? ???????????(win2k sp4, winXP sp1)?????????
• ??????????????????

242

• ?????/????
• ?????????????????

243
(No Transcript)
244
????

• TIA/EIA568??
• UTP?????
• Pair 1? pair 2? pair 3? pair 4?
• 568A
• 1 2 3 4 5 6 7 8
• ?? ? ?? ? ?? ? ?? ?
• 568B
• 1 2 3 4 5 6 7 8
• ?? ? ?? ? ?? ? ?? ?
• ????????
• ???568A----568A ? 568B----568B
• ???568A----568B
• ???????????,??????????(????MDI??????)

245
(No Transcript)
246

• ??????
• 1 2 3 4 5 6 7 8
• ?? ? ?? ? ?? ? ?? ?
• 1 2 3 4 5 6 7 8
• ?? ? ?? ? ?? ? ?? ?
• 1 2 3 4 5 6 7 8
• ?? ? ?? ? ?? ? ?? ?
• 1 2 3 4 5 6 7 8
• ?? ? ?? ? ?? ? ?? ?
• ???????????,?????gt10?,????????
• ?????????(wire map)????
• ????????????????MDI??????????????

247
IP????

• ????
• ??????
• ??DHCP
• ??????
• ?????????????,???????
• IP?????(ip??,?????)
• ????????----ping?superscan?
• ????arp?----arp a,??ip???MAC?????
• ????????(ip??,MAC??,?????)

248
(No Transcript)
249
(No Transcript)
250
??!