C2005 MCQ Mock Practice

Question 2

Which DNS record does reverse lookup?

Answer 2

PTR record

Question 3

Name 3 TCP header fields for reliability

Answer 3

Sequence #, Ack #, Window Size

Question 4

Difference between mutex and semaphore?

Answer 4

Mutex=lock, Semaphore=counter

Question 5

4 requirements for deadlock prevention?

Answer 5

1) Mutual Exclusion 2) Hold & Wait 3) No Preemption 4) Circular Wait

Question 6

Compare AES vs RSA encryption

Answer 6

AES=Symmetric/fast, RSA=Asymmetric/key exchange

Question 7

HTTP GET vs POST methods

Answer 7

GET=retrieve, POST=submit data

Question 8

Which Wireshark filter shows only HTTP traffic?

Answer 8

http

Question 9

What Linux command recursively deletes a directory?

Answer 9

rm -r

Question 10

How to check open ports on Linux?

Answer 10

netstat -tuln or ss -tuln

Question 11

Which command tests basic network connectivity?

Answer 11

ping

Question 12

How to change file permissions to 755?

Answer 12

chmod 755 filename

Question 13

Python socket programming uses which library?

Answer 13

socket

Question 14

What three fields manage IPv4 fragmentation?

Answer 14

Identification, Fragment Offset, More Fragments flag

Question 15

How does TCP congestion control handle packet loss?

Answer 15

1) Fast Retransmit (3 duplicate ACKs) 2) Timeout (halves cwnd)

Question 16

What headers enable HTTP cache validation?

Answer 16

Last-Modified/If-Modified-Since + ETag/If-None-Match

Question 17

How are monitors different from semaphores?

Answer 17

Monitors: Implicit locks, OOP-style. Semaphores: Explicit wait()/signal()

Question 18

What checks are done for HTTPS cert validation?

Answer 18

1) Expiry 2) Domain match 3) Trust chain 4) Revocation