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In the last lecture, we had an introduction to orders, denial of service attack.

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So basically denial of service DOS is an attack on a computer network that reduces, restricts or prevents

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accessibility of the same resources towards legitimate users.

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So the first type of attack is UDP third attack and attacker since spoofed Urabe Packards at a very

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high, Attrit, remote post on random parts of the target server using a large source IP range threatening

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of UDP packets cause a server to repeatedly check for nonexistent applications at the ports.

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Legitimate applications are inaccessible by the system and gives a reply with an ICMP destination unreachable

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packet.

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This attack consumes network resources and available bandwidth, exhausting the network and it goes

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offline.

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The next is ICMP third attack.

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Network administrators use ICMP primarily for IP operations, troubleshooting and error messaging of

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undeliverable packets.

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ICMP attack is a type of attack in which the attackers in large volumes of ICMP because it was because

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the victim system directly or through reflexion networks, these packets signal the victim's system

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replay and the combination of traffic saturates the bandwidth of the victims network connection, thereby

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causing it to be overwhelmed and subsequently stop responding to legitimate PXP requests to protect

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against ICN before an attack set a limit.

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Which one expert invokes the ICMP attack protection feature?

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The next is being of the attack and the peak of the attack.

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And attacker tries to crash, destabilize or freeze the targeting system or service by sending malformed

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hot over suspects using a simple Pinkham on, for instance, the attacker sends a packet which is the

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size of sixty five thousand five hundred bytes to the target.

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The possible size of the packet exceeds the size limit prescribed by the autopsy 791 IP, which is sixty

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five thousand 535 words.

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And that's what the packet which is attacking sending is three words more.

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The reassembly processed by the receiving system might cause a system to crash.

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The next is Synthron attack.

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The attacker sends a large number of requests to a target server that is the victim.

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But the fixer's IP addresses the target machine sends back a cynic in response to the request and waits

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for the ECJ to complete the station.

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Set up the machine does not get the response because the source addresses fake sincerity, takes advantage

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of a flaw in the way most hosts implement the DCB transship.

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When the host receives the scene from another host, it must keep track of the partially open connection

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in Alisson Queue for at least seventy five seconds.

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A malicious host can explore the small size of the lesson queue by sending multiple requests to the

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host, but never replace the Sinak request.

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The victims listen queue is quickly filled up.

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This ability of holding each incomplete connection for seventy five seconds can cumulatively used as

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a dinner service.

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There is simpler a type of denial of service category, and the last is fragmentation.

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Attack these attacks destroy a victim's ability to reassemble the fragmented packets by flooding it

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with DCB or Urabe fragments resulting in a reduced performance.

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Attacker sends a large number of fragments.

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It is fifteen hundred plus bite package to the target server, but relatively small packet rate.

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Since the protocol allows the fragmentation, these packets usually pass through the network equipments,

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recruiters, firewalls, ideas, IP, etc. which remain uninspected.

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Reassembling and inspecting these large, fragmented packs consumes existing resources.

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Moreover, the content in the packet fragments will be randomized by the attacker, which makes the

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process to consume more resource and leading the system to crash.

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In the next lecture, we will see what is a botnet and how botnet is used for those attacks.