??? VPN?????IPSec

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???VPN?????IPSec

• ??????VPN (Virtual Private Network)
• VPN????? - PPTP?L2TP?IPSec

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????

• VPN ????
• PPTP ( Point-to-Point Tunneling Protocol )
• L2TP ( Layer 2 Tunneling Protocol )
• IPSec ( IP Security )

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??? VPN ?

• Virtual (??) ????
• Private (??) ?????????
• Network (??) ???????????
• ????????- ???????,??????? Internet(??)
  ??????????(tunnel) ,??????????????????????????,???
  ????????????(??)

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What is VPN ?

• VPN (Virtual Private Network)???????(Internet)????
  ??????????????,????????(Virtual Private
  Network),??????????(LAN)????????????????????,?????
  ???????????(tunnel)???????????????????

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??????????
?????
???? T1, Frame Relay ISDN, ATM
????
??????
Remote User ??????
Modem Bank
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???????? VPN ??
Virtual Private Networking
?? Internet VPN ????????????
???????????
Internet
????
?? VPN ???? eMail ??? ???
??????
?????
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??? VPN ??????? ?
????
?? ISP ADSL, Cable ??
?? ISP T1 ????
??????
Public Internet
?? ISP ADSL, Cable, T1 ??
???? ISP ??
?????
???????????
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VPN ?????? ?
1. ???Internet.
2.??????????????.
3. ????????????????? VPN gateway.
Internet
4.????(Authenticate)?????.
5. VPN ??(Tunnel)????
6. ????????
Intranet
Database
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VPN ???????
?????? (Internet) ??????????,????????
Authentication ??????CHAP?RAP Encryption
??????DES?RAS Tunneling ?????? PPTP?L2TP?IPSec
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VPN ???
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VPN ???

• ???? VPN (Remote Access Scenario)
• Intranet VPN (?????)
• Extranet VPN (??????/???????)

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VPN ????
??? LAN
??????
56KBps ????
?? VPN Client Software
VPN Gateway
Mobile Users
??? LAN
ADSL, Cable ??
?? VPN Gateway
VPN Gateway
????? ?? LAN
??? LAN
T1-T3 ????
VPN Gateway
VPN Gateway
????????????
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???? VPN

• ?????VPN ?,??????? ISP ????,?? ISP ???? Internet
  ???????????,?????????????

?? VPN Client Software
Digital
VPN??
Internet
VPN??
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Intranet VPN

• ?? Internet ?????????????????? WAN ??,??Site ?
  Site ??????

VPN??
VPN??
Internet
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Extranet VPN

• ?????Extranet ???,???????????????????,? Extranet
  ??????????

Internet
????????????
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VPN Tunneling ??????
PPTP ( Point to Point Tunneling Protocol ) ?
Microsoft ?? L2TP ( Layer 2 Tunneling Protocol
) ? Cisco ?? IPSec ( Internet Protocol Security
) ? IETF (??????????) ??
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?????? (VPN)

• VPN ????
• PPTP ( Point-to-Point Tunneling Protocol )
• PPTP?????
• PPTP??????
• PPTP???
• PPTP??? ( Client to Site )
• CHAP ????
• MPPE ????
• L2TP ( Layer 2 Tunnel Protocol )
• IPSec ( IP Security )

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PPTP

• Point-to-Ponit Tunneling Protocol
• Layer 2 ???
• PPP ( Point to Point ) ???
• ???LAN ???,?IP, IPX, NetBeui
• ??IP network ????
• ??MPPE ( Microsoft Point to Point Encryption
  )??????

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PPTP?????

• ????????????PPTP Driver??
• ?????PPTP Driver??????????
• ???????????????

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PPTP??????

• PPTP??????????PPP?????
• PAP, SPAP, CHAP, MS-CHAP V1, V2, and EAP
• PPTP??MPPE???????
• ????MS-CHAP V1 or 2 or EAP-TLS????????MPPE??????

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PPTP???

• ???????????????,??? Win98/XP/NT4/2000 Client

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PPTP???

• ??????????

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PPTP ???(CHAP )
PPTP Server203.77.21.10 192.168.0.254
DB Server192.168.0.3
Mobile User(??)
???(??) 192.168.0.0/24
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PPTP ???(CHAP )

• ????RedHat 7.3
• ??????
• ppp-2.4. .rpm
• http//www.spenneberg.org/VPN/pptpd-1.1.3-2.i386.
  rpm
• ?? rpm Uvh ??

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PPTP ???(CHAP )

• /etc/pptpd.confspeed 115200localip
  192.168.0.254remoteip 192.168.0.11-20

• /etc/ppp/optionsdebugname servernameauthrequir
  e-chap

• /etc/ppp/chap-secretsalex servername password
• service pptpd start

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PPTP ???(CHAP )
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PPTP ???(CHAP )
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?????? (VPN)

• VPN ????
• PPTP ( Point-to-Point Tunneling Protocol )
• L2TP ( Layer 2 Tunneling Protocol )
• L2TP?????
• L2TP??????
• L2TP???
• IPSec ( IP Security )

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L2TP

• Layer 2 Tunneling Protocol
• ??????
• ???LAN ???,?IP, IPX, NetBeui
• ???IP, X.25, ATM, Frame Relay????
• ??IPSec??????

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L2TP?????

• ????????????L2TP Driver??
• ?????L2TP Driver????????IPSec?????
• ???????????????

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L2TP?????

• L2TP??????????,??????????
• ???????certificate base,?IPSec??SA???????
• ??????????PPP???
• EAP, MS-CHAP V1, V2, CHAP, SPAP, and PAP
• L2TP??IPSec????????
• DES with a 56-bit key
• Triple DES (3DES)

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L2TP??

• ???????????????,???W2K Client

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L2TP??

• ??????????

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QA