Internet applications¶
Multiple choice questions¶
The Domain Name System¶
- Which of the following DNS Resource Records should be queried to retrieve the IPv6 address associated to a name ?
The MX record.
The NS record.
- You use the DNS to retrieve the IPv4 address associated to the name cnp3book.info.ucl.ac.be. Assuming that you need to start your query from the root of the domain name system, which of the following DNS record will you never query to obtain this information.
The AAAA record.
The A record.
The MX record.
Electronic mail¶
- Which of the following affirmations about electronic mail on the Internet are valid ? Select all the correct ones in the list.
The SMTP protocol is used by the recipient to retrieve his/her email messages.
- The format of the Internet emails is defined in RFC 2822. This specification describes all the nitty details of the format of email messages. The bullets below show several email messages. Only one of them is syntactically valid. Which one ?
From: Alice <alice@example.net>
To: Bob <mary@example.com>
Subject: Saying Hello
Date: Fri, 21 Nov 1997 09:55:06 -0600
This is a message just to say hello.
So, "Hello".
From: Alice "alice@example.net"
Subject: Saying Hello
Date: Fri, 21 Nov 1997 09:55:06 -0600
To: Bob "mary@example.com"
This is a message just to say hello.
So, "Hello".
From: Alice "alice@example.net"
Subject: Saying Hello
Date: Fri, 21 Nov 1997 09:55:06 -0600
To: Bob "mary@example.com"
This is a message just to say hello.
So, "Hello".
- The SMTP protocol is a key protocol for the delivery of Internet email messages. This protocol is a stateful protocol where the client sends commands to the server. Which of the following affirmations about the SMTP commands are correct ? Select all the valid ones.
The HELO command is the first command sent by a client on an SMTP session. It is always followed by a domain name as in the example below :
HELO uclouvain.be
The MAIL FROM: command can only be issued after the DATA comment. It contains as parameter a valid email address as in the example below :
MAIL FROM: <bob@example.com>
The MAIL FROM: command must be issued before the DATA comment. It contains as parameter a valid email address as in the example below :
MAIL FROM: <alice@example.net>
A Base64 encoded string can only contain letters (A-Z and a-z) and digits (0-9)
The HyperText Transfer Protocol¶
- The Uniform Resource Identifiers (URI) defined in RFC 3986 are a key element of the world wide web. Among the URIs below, select the ones that are valid URIs.
http://example.net@/example.com
http:80//example.com/index.html
http://example.com:user/index.html
- The Uniform Resource Identifiers (URI) defined in RFC 3986 are used to indicate the domain name of the server that needs to be contacted to retrieve a document. Which of the following affirmations are valid for these URIs ?
- Which of the following affirmations are valid concerning the HTTP protocol ? Select all the valid affirmations from the ones listed below.
HTTP is a stateful protocol.
HTTP supports a single method : GET
- The extensibility of the HTTP protocol comes from the various header lines that it supports. Some of these header lines appear inside requests while others appear inside responses. Among the following affirmations about these headers, select the ones that are valid.
The Content-Length, Content-Type and Content-Encoding header lines may appear inside HTTP requests.
The Content-Length, Content-Type and Content-Encoding header lines can only appear inside HTTP responses.