[Day 1] 7. Extra

1. Ping Command Behavior
   • Using the
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     -c

     flag in the
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     ping

     command to limit the number of packets sent to the target IP.
   • In Linux, the default number of packets sent is infinite.
   • In Windows, the default number of packets sent is 4.

1. DNS Usage

   • DNS primarily resolves domain names to IP addresses and vice versa. Resolving protocol names to port numbers is not a function of DNS but is typically handled by the IANA port number registry or local system files like
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     /etc/services

     on Unix-like systems.

2. TCPDump with

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   -n

   Flag
   • When using the
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     -n

     flag with the
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     tcpdump

     command, we apply a no resolution rule, meaning the actual port numbers will be shown instead of resolved names.

   shellCopy
     sudo tcpdump -c 10 -n
   

Key clustering occurs when different encryption keys produce the same ciphertext for the same plaintext, reducing the effectiveness and uniqueness of the encryption algorithm.