CCNA CyberOps Chapter 7 Exam Online

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A network tap is used to capture traffic for monitoring the network. The tap is typically a passive splitting device implemented inline on the network and forwards all traffic including physical layer errors to an analysis device. SPAN is a port mirroring technology supported on Cisco switches that enables the switch to copy frames and forward them to an analysis device.

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• When enabled on a switch, port mirroring copies frames sent and recieved by the switch and forwards them to another port, which has a analysis device attached.

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When enabled on a switch, SPAN or port mirroring, copies frames that are sent and received by the switch and forwards them to another port, known as a Switch Port Analyzer port, which has a analysis device attached.

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There are many SIEM systems available to network administrators. The ELK suite is an open source option.

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NetFlow is a Cisco technology that provides statistics on packets flowing through a Cisco router or multilayer switch.

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The correlation function of SIEM speeds the detection and reaction to security threats by examining logs and events from different systems.

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The aggregation function of SIEM reduces the volume of event data by consolidating duplicate event records.

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FTP is an unsecure network protocol. Anyone capturing packets can obtain the username and password from the capture. A more secure protocol such as SFTP should be used.

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The Simple Network Management Protocol is used by network devices to send and log messages to a syslog server in order to monitor traffic and network device events.

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Wireshark captures are saved as PCAP files, which contain frame, interface, and packet information, and also time stamps.

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IPv6 uses extension headers to carry optional network layer information. Extension headers are not part of the main IPv6 header but are separate headers placed between the IPv6 header and the payload.

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DDoS is a distributed denial-of-services attack. A DDoS attack is launched from multiple coordinated sources. The sources of the attack are zombie hosts that the cybercriminal has built into a botnet. When ready, the cybercriminal instructs the botnet of zombies to attack the chosen target.

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In a TCP SYN flood attack, the attacker sends to the target host a continuous flood of TCP SYN session requests with a spoofed source IP address. The target host responds with a TCP-SYN-ACK to each of the SYN session requests and waits for a TCP ACK that will never arrive. Eventually the target is overwhelmed with half-open TCP connections.

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Fast flux, double IP flux, and domain generation algorithms are used by cybercrimals to attack DNS servers and affect DNS services. Fast flux is a technique used to hide phishing and malware delivery sites behind a quickly-changing network of compromised DNS hosts (bots within botnets). The double IP flux technique rapidly changes the hostname to IP address mappings and the authoritative name server. Domain generation algorithms randomly generate domain names to be used as rendezvous points.

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DCHP starvation attacks are launched by an attacker with the intent to create a DoS for DHCP clients. To accomplish this goal, the attacker uses a tool that sends many DHCPDISCOVER messages in order to lease the entire pool of available IP addresses, thus denying them to legitimate hosts.

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Two threats to DNS are DNS shadowing and DNS tunneling attacks. DNS shadowing attacks compromise a parent domain and then the cybercriminal creates subdomains to be used in attacks. DNS tunneling attacks build botnets to bypass traditional security solutions. Three threats to DNS open resolvers are cache poisoning, amplification and reflection, and resource utilization attacks.

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A cybercriminal could set up a rogue DHCP server that provides one or more of the following:Wrong default gateway that is used to create a man-in-the-middle attack and allow the attacker to intercept data
Wrong DNS server that results in the user being sent to a malicious website
Invalid default gateway IP address that results in a denial of service attack on the DHCP client

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ARP poisoning attacks can be passive or active. The result of a passive attack is that cybercriminals steal confidential information. With an active attack, cybercriminals modify data in transit or they inject malicious data.

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In a DNS cache poisoning attack, falsified information is used to redirect users from legitimate to malicious internet sites.

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A criminal can insert a malicious SQL statement in an entry field on a website where the system does not filter the user input correctly.

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Spam is annoying and unwanted bulk email that is sent to as many end users as possible.

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An HTML element known as an inline frame or iFrame allows the browser to load a different web page from another source.

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The HTTP 302 cushioning attack is used by cybercriminals to take advantage of the 302 Found HTTP response status code to redirect the browser of the user to a new location, usually a malicious site.