CCNA 3 - Capitulo 3.6

CCNA 3 - Capitulo 3.6

1. NETWORK SECURITY CONCEPTS

   • VULNERABILITIES TCP E UDP
     • TCP ATTACKS
       • TCP SYN FLOOD ATTACK
         • EXPLOITS THE TCP THREE WAY HANDSHAKE
           • HOW TO WORK ?
             • 1 . THREAT ACTOR SENDING TCP SYN SESSION REQUEST WITH A RAMDOMLY SOURCE IP SPOOFED
             • 2. TARGET SERVER REPLIES WITH A TCP SYN ACK AND WAITS FOR A TCP ACK PACKET . THOSE RESPONSES NEVER ARRIVE
             • 3. TARGET HOST IS OVERHELMED WITH HALF OPEN TCP AND TCP ARE DENIED TO LEGITIMATE USERS
         • HALF OPEN
       • TCP RESET ATTACK (RST)
         • CIVILIZED MANNER
           • FOUR WAY PAYER FIN & ACK
         • UNCIVILIZED MANNER
           • SEGMENT TCP - BIT
             • RST
           • SPOOFING BIT RST
         • CAN BE USED TO TERMINATE TCP COMMUNICATONS BETWEEN TWO HOSTS
       • SESSION HIJACKING TCP
         • THREAT ACTOR TAKER OVER AN ALREADY AUTHENTICATED HOST WITH THE TARGET
         • HOW DOES IT WORK ?
           • THREAT ACTOR SPOOF THE IP OF ONE HOST A
             • ND PREDICT THE NEXT SEQUENCE NUMBER
     • UDP ATTACKS
       • UDP ATTACKS
         • UDP FLOOD
           • ALL THE RESOURCES ON A NETWORK ARE CONSUMED
           • USE A TOOL LIKE
             • UDP UNICRON OR LOW ORBIT ION CANNON
       • MAKES VERY DESIRABLE FOR PROTOCOLS MAKES SIMPLE REQUEST AND REPLY
       • ENCRYPTION TO UDP IS NOT AVAILABLE BY DEFAULT
     • TCP SERVICES
       • RELIBLE DELIVERY
         • INCORPORATE ACK TO GUARANATE DELIVERY
       • FLOW CONTROL
       • STATEFUL COMMUNICATION
         • BEFORE DATA CAN BE TRANSFERRED USING TCP A TREE WAY HANSHAKE OPEN THE CONNECTION