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习题
P1.
a. 错
b. 对
c. 错
d. 错
e. 错
P2.
FTP SERVICE COMMANDS:
RETRIEVE (RETR)
STORE (STOR)
STORE UNIQUE (STOU)
APPEND (with create) (APPE)
ALLOCATE (ALLO)
RESTART (REST)
RENAME FROM (RNFR)
RENAME TO (RNTO)
ABORT (ABOR)
DELETE (DELE)
REMOVE DIRECTORY (RMD)
MAKE DIRECTORY (MKD)
PRINT WORKING DIRECTORY (PWD)
LIST (LIST)
NAME LIST (NLST)
SITE PARAMETERS (SITE)
SYSTEM (SYST)
STATUS (STAT)
HELP (HELP)
NOOP (NOOP)
P3.
应用层：DNS HTTP
运输层：TCP(HTTP需要) UDP(DNS需要)
P4.
a.
gaia.cs.umass.edu/cs453/index.html
b.
1.1
c.
持续
d.
HTTP 报文中没有 IP 地址
e.
Mozilla/5.0 可以针对不同的浏览器发送不同版本的网页
P5.
a.
能
Tue, 07 Mar 2008 12:39:45 GMT
b.
Last-Modified: Sat, 10 Dec 2005 18:27:46 GMT
c.
Content-Length: 3874
d.
前五个字节："<!doc"
根据 keep-alive 看出同意持续连接
P6.
a.
An HTTP/1.1 server MAY assume that a HTTP/1.1 client intends to
maintain a persistent connection unless a Connection header including
the connection-token "close" was sent in the request. If the server
chooses to close the connection immediately after sending the
response, it SHOULD send a Connection header including the
connection-token close.
An HTTP/1.1 client MAY expect a connection to remain open, but would
decide to keep it open based on whether the response from a server
contains a Connection header with the connection-token close. In case
the client does not want to maintain a connection for more than that
request, it SHOULD send a Connection header including the
connection-token close.
If either the client or the server sends the close token in the
Connection header, that request becomes the last one for the
connection.
b.