News & Tools
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- Cybersecurity & Infrastructure Security Agency (CISA): Free Cybersecurity Services and Tools
- As part of our continuing mission to reduce cybersecurity risk across U.S. critical infrastructure partners and state, local, tribal, and territorial governments, CISA has compiled a list of free cybersecurity tools and services to help organizations further advance their security capabilities. This living repository includes cybersecurity services provided by CISA, widely used open source tools, and free tools and services offered by private and public sector organizations across the cybersecurity community. CISA will implement a process for organizations to submit additional free tools and services for inclusion on this list in the future.
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- Apple Patches Actively Exploited WebKit Zero Day
- In re: Zoom Video Communications, Inc. Privacy Litigation
- Mac Malware Targets Apple’s In-House M1 Processor : A malicious adware-distributing application specifically targets Apple’s new M1 SoC, used in its newest-generation MacBook Air, MacBook Pro and Mac mini devices.
- Mysterious Silver Sparrow Malware Found Nesting on 30K Macs – A second malware that targets Macs with Apple’s in-house M1 chip is infecting machines worldwide — but it’s unclear why.
- NY Payroll Company Vanishes With $35 Million
- Cheat Sheets – Wall Posters (36″ x 24″) (PacketLife.net)
- What the #$%@ is UX Design? by UX Mastery
Assignment #1 Debriefing
Subnetting Tutorial & Reference Page
- If no mask/prefix is given, then borrow bits starting from the “Class” boundary of the IP address.
- If a mask/prefix is given, then the given mask/prefix is the result of subnetting. (Borrow bits from the “Class” boundary to the given mask/prefix.)
- The total number of subnets must be a power of 2.
- The total number of hosts must be a power of 2.
- Is the question asking for “subnets” or “hosts”
- If you’re asked for the # of hosts, then you must determine how many bits are needed to get that # of hosts, then subtract those bits from the 32 IPv4 bits, to determine the network bits / mask / prefix.
- Determine the number of subnets: 2 [number of bits borrowed].
- Determine the total number of addresses: 2 [the number of host bits].
- Add the Wildcard mask to the network/subnet address to determine the broadcast/last address in the network/subnet.
- Block Size:
- The block size (256 – [The interesting octet]) is best used to determine the increment of the subnets.
- The interesting octet is the last octet, from the left, that you borrowed bits from.
- The “block size” is the increment from one subnet to the next, within the “interesting” octet. It is not the number of addresses per subnet.
- Practice makes improvement!
We’ll cover Large Number of Subnets and Decimal to Base-256 dotted-decimal conversion during our next class
Do: Assignment #2: Due before Thurs. Feb. 24, 2022 6pm EST
- Download the Assignment
- Important: Make sure to read and understand the instructions on how to handle the protected PDF
- If you have any issues completing all parts of every question on the assignment, e-mail me with the question # and the specifics you need assistance with.
- No late assignments will be accepted.
- Review Examples: IPv4-CustomSubnetMasks-Examples-1-3.pdf
- Memorize these Bit Patterns of Often Used Subnet Mask Values (pdf)
Make sure to always have access to a calculator which has an Exponent function (^key) ( xy ) for every class.