1. Well-known port numbers are contained in the file /etc/services on most Unix
ID: 3584920 • Letter: 1
Question
1. Well-known port numbers are contained in the file
/etc/services on most Unix systems. Use "grep" to determine
the port number(s) and transport layer protocol(s) (e.g. TCP,
UDP, etc.) used by the following servers/services:
(a) Echo
(b) Daytime
(c) FTP
(d) TFTP
Why is it important for servers of the same type (e.g., ftp
servers) to use the same well-known port number? Hint:
execute $ grep ftp /etc/services to find all lines in the
/etc/services file that contains the string "ftp".
2. What is the role of the portmapper in a client-server
application that uses Remote Procedure Calls (RPC)? Is it
important for the portmapper to be bound to a well-known
port? Is it important for RPC Servers to be bound to
well-known ports? Why?
3. RFC 5952 section 4 defines a canonical text format for usual
IPv6 addresses. Section 5 discusses "special" addresses.
Specify how the following addresses would be represented in
this format:
(a) 2001:DB8:0:0:0:1:0:1
(b) 2001:DB8:0:0:1:0:0:1
(c) 2001:DB8:0:1:1:1:1:1
(d) 2001:DB8:0:1:0:0:0:1
(e) 0:0:0:0:0:FFFF:129.130.10.5
Explanation / Answer
Answer:
1) FTP , it uses port 21 with UDP or TCP.
Port for FTP :
&grep ftp/etc/services ftp 21/tcp ftp 21/udpRelated Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.