24. Which filtering method uses the physical address to specify exactly which device isallowed or blocked from sending data on a network?MAC address filtering*port forwardingport triggeringwhitelistingExplanation:MAC address filtering specifies exactly which device MAC addresses are allowedto or blocked from sending data on your network.
Through this process, certain routes are not considered for inclusion in the local route database or not announced. Filters can be applied at the routers, before the routes are announced (output filtering) or as soon as a route is learned (input filtering). There are different reasons for filtering:
In some cases, routers have insufficient amounts of main memory to hold the full global BGP table. By applying input filtering on prefix length (eliminating all routes for prefixes longer than a given value), on AS count, or on some combination of the two, the local route database is limited to a subset of the global table. This practice is not recommended, as it can cause sub-optimal routing or even communication failures with small networks, and frustrate the traffic-engineering efforts of one’s peers. In the past, route filtering was also used to prevent IPv4 blocks that are not yet delegated by IANA, commonly called bogon address space. As IANA has depleted its available IPv4 address space, this practice is no longer needed. Some networks are now blocking IPv4 prefixes that are being held at the Regional Internet Registries (RIR) and not yet delegated to any network. As RIRs delegate resources on a daily basis, this practice requires a daily update to the route filter. Unless a network has an automated and reliable tool to check the RIR databases, it is best not to perform this level of route filtering. Firewall filteringA firewall is a device, a set of devices, or a software application designed to permit or deny network transmissions based upon a set of rules to protect networks from unauthorized access while permitting legitimate traffic to pass. Many routers that pass data between networks contain firewall components and, conversely, many firewalls can perform basic routing functions. The different types of firewalls that can be defined depending on where the communication is taking place, where the communication is intercepted, and the state that is being traced.
Firewall filtering requires constant adjustments to reflect the latest security policies, threat conditions, and address holdings. Outdated policies such as blocking IPv6 by default, or blocking certain IP addresses that sends malicious traffic, or blocking a whole network/ISP/Country may need to be reviewed from time to time to ensure overall network visibility do not degrade as more and more traffic gets accidentally discarded. Email filteringEmail filtering is the manual or automatic processing of incoming emails to organize them according to set criteria (topic, sender, etc) and removal of spam and computer viruses. The filters allow clean messages to be delivered to the user’s mailbox, while redirecting tainted messages for delivery to a quarantine application for the user’s review, or even ignore them. Some mail filters are able to edit messages during processing, for example deactivating URLs in email messages to remove the threat before users click. Although less common, some companies inspect outgoing email to oversee that their employees comply with law requirements. Email filters operate through a variety of techniques from matching a regular expression, a keyword, or the sender email address. More advanced solutions use statistical document classification techniques, IP reputation, and complex image analysis algorithms to prevent messages from reaching protected mailboxes. Email filtering becomes problematic when a blacklisted IP address is transferred to a new network. The new network may have the mail traffic from the blacklisted IP address blocked and will have to contact various blacklist maintainers to delist the address. APNIC will be able to provide assistance by confirming to the blocking parties that the blacklisted address has changed hands, as long as the transfer was properly registered in the APNIC Whois Database. This information was compiled after reviewing the following sources: Wikipedia, SpamHaus, ReturnPath and MAAWG published documents. May 29, 2022 Last Updated: May 29, 2022 Which filtering method uses IP addresses to specify allowed devices on your network?
Explanation: Whitelisting and blacklisting specify which IP addresses are allowed or denied on your network. This is typically done using an access list or access policy. More Questions: IT Essentials v7.01 Chapter 6 Quiz Answers Would love your thoughts, please comment.x ← What command can be used to troubleshoot domain name resolution issues? ← Which type of laptop display has components that may contain mercury and use either a CCFL or LED backlight? |