Maintaining network availability

- Sometimes attackers try to undermine network security…by denying legitimate users access to the network.…Let's take a look at two techniques you can implement…to defend your network against availability-based attacks.…Many denial of service attacks rely upon flooding devices…with traffic until they are overwhelmed.…I cover many of these…in the Security Plus Threats and Vulnerabilities course.…One example of this type of attack is the SYN Flood.…You may recall that in a SYN Flood attack,…the attacker creates thousands…of partially opened TCP connections to a device…by sending SYN packets…but never answering the SYN ACK packet…to complete the three-way handshake.…

This is one example of flooding,…and there are many similar attacks…in the attacker's toolkit.…Another example, MAC Flooding, occurs…when attackers send large numbers of different MAC addresses…to a switch, hoping to overflow…the switch's MAC address table…and cause it forget where devices are…and then, flood traffic out to every switch port,…allowing the attacker to eavesdrop…