ارایه ای که در کارگاه بیان می شود به شرح زیر است: مقدمات ، توضیحاتی اولیه در مورد footprint و شناسایی ، رمز نگاری ، اسکن ، نفوذ ، آشنایی با ویروس ها ، تروجان ، backdoors و ورم ، آشنایی با DoS ،Web Application Hacking ، شبکه های بیسیم ، programming attacks و توضیحاتی در مورد Intrusion

1. ‫کامپیو‬ ‫های‬ ‫شبکه‬ ‫در‬ ‫اختالل‬ ‫با‬ ‫رابطه‬ ‫در‬ ‫سناریو‬ ‫دو‬ ‫بررسی‬‫تری‬
(DHCP SPOOFING & CAM TABLE OVERFLOW)
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2. TABLE OF CONTENTS
• Introduction of CAM Table Overflow Attack
• Explain CAM Table Overflow Attack
• How to Defend!
2
• Introduction of DHCP Spoofing Attack
• Explain DHCP Spoofing Attack
• How to Defend!
CAM Table Overflow Attack DHCP Spoofing Attack
The Goal of This Seminar

3. THE GOAL OF THIS SEMINAR
• According to a study by the FBI, an estimated 70 percent of these network breaches
originate from within.
• Disorder in computer networks is not a big work . It is just abuse of some simple Rules.
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4. CAM Table overflow Attack
• Introduction of CAM Table Overflow Attack
4

5. 500-50-56-C0-00-02
COM1
70-1A-04-FF-F1-67
COM2
Port 1 Port 2 Port 3 Port 4
CAM Table
00-50-56-
C0-00-02
? YES!!
70-1A-04-
FF-F1-67

6. CAM Table overflow Attack
• Introduction of CAM Table Overflow Attack
• Explain CAM Table Overflow Attack
6

7. 700-50-56-C0-00-02
COM1
70-1A-04-FF-F1-67
COM2
Port 1 Port 2 Port 3 Port 4
CAM Table
00-50-56-
C0-00-02
70-1A-04-
FF-F1-67
28-50-56-
C0-00-02
43-50-56-
86-00-02
A3-00-56-
86-00-02
98-BC-56-
86-00-02
F3-64-56-
86-00-02

8. 8

9. CAM Table overflow Attack
• Introduction of CAM Table Overflow Attack
• Explain CAM Table Overflow Attack
• How to Defend!
9

10. THE SOLUTION IS:
Port Security
10

11. 1100-50-56-C0-00-02
COM1
70-1A-04-FF-F1-67
COM2
Port 1 Port 2 Port 3 Port 4
CAM Table
00-50-56-
C0-00-02
70-1A-04-
FF-F1-67
28-50-56-
C0-00-02
43-50-56-
86-00-02
Configure Port Security on all the ports of switch

12. DHCP Spoofing Attack
• Introduction of DHCP Spoofing Attack
12

13. 13MAC(COM1)
COM1
IP Address
Kinds of Communication in
Computer Networks
1.Unicast
2.Multicast
3.Broadcast
Source IP: 0.0.0.0
Destination IP: 255.255.255.255
Source MAC: MAC(COM1)
Destination MAC : FF-FF-FF-FF-FF-FF
UDP Connection
Destination Port: 67
DHCP Discover
DHCP Offer
DHCP Request
DHCPAcknowledgment
DHCP Server
MAC(DHCP)
IP:10.1.1.100
Source IP: 10.1.1.100
Destination IP: 255.255.255.255
Source MAC: MAC(DHCP)
Destination MAC : FF-FF-FF-FF-FF-FF
UDP Connection
Destination Port: 68
MAC Address Leased IP
MAC(COM1) 10.1.1.20

14. DHCP Spoofing Attack
• Introduction of DHCP Spoofing Attack
• Explain DHCP Spoofing Attack
14

15. 15MAC(COM1)
COM1
IP Address
DHCP Server
MAC(DHCP)
IP:10.1.1.100
I want an IP!
This is your IP and if you
want to go to Internet use
this Gateway!
MAC1,MAC2 ,
MAC3 ,MAC4
,…………………
……
Hey DHCP Server! I
have these MACs .
Give IP Addresses
for these IPs !!!
OK, Here You Are!
OK, Here You Are!
OK, Here You Are!
OK, Here You Are!
.
.
.
.
NOW..I am DHCP Server
I Do not have anything!!!

16. DHCP Spoofing Attack
• Introduction of DHCP Spoofing Attack
• Explain DHCP Spoofing Attack
• How to Defend!
16

17. THE SOLUTION IS:
DHCP Snooping
17

18. 18MAC(COM1)
COM1
IP Address
DHCP Server
MAC(DHCP)
IP:10.1.1.100
DHCP Snooping Enabled Switch
DHCP Snooping says: “This
Port is allowed to be the
port of DHCP Server!”
NOW..I became myself
DHCP Server!!
No You can not!
because your port is
not trusted by switch!

19. CONCLUSION
Disorder in computer networks is not a big work .
It is just abuse of some simple Rules.
19

20. PAPERS & REPORT
20

21. PAPERS & REPORT
21

22. PAPERS & REPORT
22

23. REFERENCES
23
CCNA Security
Official Exam Certification Guide
(Chapter 6 : Securing Layer 2 Devices)

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‫عزیز‬ ‫دوستان‬ ‫شما‬ ‫همراهی‬ ‫از‬ ‫تشکر‬ ‫با‬

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