List the six external parts of a computer system and identify which are output and which and which are input devices

Which virus-infecting components are email messages prone to carry? one of the problems associated with the use of email communication is that email messages are prone to carry virus-infecting .

You are working as a security analyst in a company xyz that owns the whole subnet range of 23.0.0.0/8 and 192.168.0.0/8. while monitoring the data, you find a high number of outbound connections. you see that ip's owned by xyz (internal) and private ip's are communicating to a single public ip. therefore, the internal ip's are sending data to the public ip. after further analysis, you find out that this public ip is a blacklisted ip, and the internal communicating devices are compromised. what kind of attack does the above scenario depict?

Consider a slotted aloha system, where the time slot equals the fixed duration of each packet. assume that there are 4 stations a,b,c,d sharing the medium. (a) stations a,b,c,d receive one packet each from higher layers at times 1.3, 1.5, 2.6,5.7 respectively. show which transmissions take place when, according to the slottedaloha protocol; describe all transmissions until all four packets have been successful.when needed, each station has access to the following sequence of random number, provided by a random number generator and drawn uniformly between 0 and 1: (1) station a draws numbers: 0.31, 0.27, 0.78, 0.9, 0.9, 0.11, 0. (2) station b draws numbers: 0.45, 0.28, 0.11, 0.83, 0.37, 0.22, 0. (3)station c draws numbers: 0.1, 0.2, 0.3, 0.4, 0. (4) station d draws numbers: 0.36, 0.77, 0.9, 0.1, 0.1, 0.1, 0.1, 0. (b) in slotted aloha, a station transmits in each time slot with a given probability. what probabilities would you assign to each of the four stations so as to: (i) maximize the efficiency of the protocol? (ii) maximize fairness among the four stations? (c) will the efficiency increase or decrease if we modify slotted aloha as follows: (i) get rid of slots and allow stations to transmit immediately? (ii) implement carrier sensing? (iii) implement collision detection? (iv) implement collision avoidance?