Suppose a client sends an HTTP request message with the If-modified-since header. Sup- pose the object in a server has not changed since the last time a client retrieved the object. Then the server will send a response message with the status code: A. 200 OK B. 404 Not Found C. 304 Not Modified D. none of the above

Suppose a client sends an HTTP request message with the If-modified-since header. Sup- pose the object in a server has not changed since the last time a client retrieved the object. Then the server will send a response message with the status code: A. 200 OK B. 404 Not Found C. 304 Not Modified D. none of the above

A+ Guide To It Technical Support

10th Edition

ISBN:9780357108291

Author:ANDREWS, Jean.

Publisher:ANDREWS, Jean.

Chapter18: Macos, Linux, And Scripting

Section: Chapter Questions

Problem 14TC

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The text below shows a reply sent from the server in response to a http GET message. What are the first 5 bytes of the document retrieved? HTTP/1.1 200 OK<cr><lf>Date: Tue, 07 Mar 2008 12:39:45GMT<cr><lf>Server: Apache/2.0.52 (Fedora) <cr><lf>Last-Modified: Sat, 10 Dec2005 18:27:46 GMT<cr><lf>ETag: “526c3-f22-a88a4c80”<cr><lf>Accept- Ranges: bytes<cr><lf>Content-Length: 3874<cr><lf> Keep-Alive: timeout=max=100<cr><lf>Connection: Keep-Alive<cr><lf>Content-Type: text/html; charset= ISO-8859-1<cr><lf><cr><lf><!doctype html public “- //w3c//dtd html 4.0 transitional//en”><lf><html><lf> <head><lf> <meta http-equiv=”Content-Type” content=”text/html; charset=iso-8859-1”><lf> <meta name=”GENERATOR” content=”Mozilla/4.79 [en] (Windows NT 5.0; U) Netscape]”><lf> <title>CMPSCI 453 / 591 / NTU-ST550A…
4. The text below shows the reply sent from a server in response to an HTTP GET message as captured by Wireshark. HTTP/1.1 200 OK\r\n Date: Fri, 27 Jan 2023 21:23:36 GMT\r\n Server: Apache/2.4.6 (CentOS) OpenSSL/1.0.2k-fips PHP/7.4.33 mod_perl/2.0.11 Perl/v5.16.3\r\n Last-Modified: Tue, 01 Mar 2016 18:57:50 GMT\r\n ETag: "a5b-52d015789ee9e"\r\n Accept-Ranges: bytes\r\n Content-Length: 2651\r\n Keep-Alive: timeout=5, max=100\r\n Connection: Keep-Alive\r\n Content-Type: text/html; charset=UTF-8\r\n \r\n [HTTP response 1/1] [Time since request: 0.035874000 seconds] [Request in frame: 784] [Request URI: http://gaia.cs.umass.edu/] File Data: 2651 bytes Line-based text data: text/html (68 lines) <html>\n <head>\n <title>Computer Network Research Group - UMass Amherst\n </title>\n </head>\n <body bgcolor="#ffffff">\n More document text follows, though not shown here. Answer the following questions, indicating where in the message above you find the…
An attacker tries to do banner grabbing on a remote web server and executes the following command:$ nmap -sV hackme.com -p 80 He gets the following output:Starting Nmap 7.90 ( http://nmap.org ) at 2020-09-26 22:47 ESTNmap scan report for hackme.com (108.58.137.114)Host is up (0.048s latency).PORT STATE SERVICE VERSION80/tcp open http Apache httpdService detection performed. Please report any incorrect results at http://nmap.org/submit/.Nmap done: 1 IP address (1 host up) scanned in 7.36 seconds What did the hacker accomplish? nmap can’t retrieve the version number of any running remote service. The hacker successfully completed the banner grabbing. The hacker should have used nmap -O host.domain.com. The hacker failed to do banner grabbing as he didn’t get the version of the Apache web server.
PLEASE LOOK AT MY QUESTION CAREFULLY ! PLEASE LOOK AT MY QUESTION CAREFULLY ! PLEASE LOOK AT MY QUESTION CAREFULLY ! the nodejs server code is like this const http = require("http");const url = require('url'); var hostName = '127.0.0.1';var port = 3000; var server = http.createServer(function(req,res){res.setHeader('Content-Type','text/plain');const parsed = url.parse(req.url);const pathname = parsed['pathname'] const queryObject = url.parse(req.url,true).query;let queryValue = queryObject['name'] if(queryValue==null){queryValue=""} if (pathname=="/"){res.end("SUCCESS!")}else if (pathname=="/echo"){res.end("SUCCESS! echo")} else if (pathname=="/foxtrot/:name"){queryValue = queryObject['name'].toString()res.end("SUCCESS! Received "+queryValue+" via foxtrot")}else{res.end("FAILED! Fix your URL.")} }) server.listen(port,hostName,()=>{console.log(`Server running at http://${hostName}:${port}/`);}); ======================== when i enter http://localhost:3000/foxrot/kilo i hope it…
2.2-8 A detailed look at an HTTP reply. Suppose now the server sends the following HTTP response message the client: HTTP/1.0 200 OKDate: Wed, 09 Sep 2020 23:46:21 +0000Server: Apache/2.2.3 (CentOS)Last-Modified: Wed, 09 Sep 2020 23:51:41 +0000ETag:17dc6-a5c-bf716880.Content-Length: 418Connection: CloseContent-type: image/html Will the web server close the TCP connection after sending this message?
Suppose an HTTP client makes a first GET request to the gaia.cs.umass.edu web server for a base page that it has never before requested, which contains an embedded object, which causes the client to make a second GET request. A very short time later, the client then makes a third GET request - for the same base page, with that third GET request having an If-Modified-Since field (as does the 4th GET request that the client makes for the embedded object). Neither the base object nor the jpeg object has changed. How many round trip times (RTTs) are needed from when the client first makes the third GET request (i.e., when it requests the base object for the second time) to when the base page and the jpeg file are displayed a second time, assuming that: any time needed by the server to transmit the base file, or the jpeg file into the server's link is (each) equal to 1/2 RTT the time needed to transmit an HTTP GET into the client's link is zero? the time needed by the server to transmit…
HTTP 1.0 GET with an embedded object. Suppose an HTTP client makes a request to the gaia.cs.umass.edu web server. The client has never before requested a given base object, nor has it communicated recently with the gaia.cs.umass.edu server. You can assume, however, that the client host knows the IP address of gaia.cs.umass.edu. Suppose also that after downloading the base file, the browser encounters a jpeg object in the base html file that is stored on gaia.cs.umass.edu, and therefore makes another GET request to gaia.cs.umass.edu for that referenced jpeg object. How many round trip times (RTTs) are needed from when the client first makes the request to when the base page and the jpeg file are completely downloaded, assuming the time needed by the server to transmit the base file, or the jpeg file into the server's link is (each) equal to 1/2 RTT and that the time needed to transmit the HTTP GET into the client's link is zero? You should assume that HTTP 1.0 is being used.…
use nodejs to create a server that URL with hostname, port, path foxtrot and route parameter value kilo Request message URL: 0.0.1:3000/foxtrot/kilo Response message: “SUCCESS! Received kilo via foxtrot” where the value kilo must be retrieved via the route parameter Invalid/unexpected URL Request message URL: 0.0.1:3000/<any other value> Response message: “FAILED! Fix your URL.”
Suppose an HTTP client makes a request to the gaia.cs.umass.edu web server. The client has never before requested a given base object, nor has it communicated recently with the gaia.cs.umass.edu server. You can assume, however, that the client host knows the IP address of gaia.cs.umass.edu. How many round trip times (RTTs) are needed from when the client first makes the request to when the base page is completely downloaded, assuming the time needed by the server to transmit the base file into the server's link is equal to 1/2 RTT and that the time needed to transmit the HTTP GET into the client's link is zero? (You should take into account any TCP setup time required before the HTTP GET is actually sent by the client, the time needed for the server to transmit the requested object, and any propagation delays not accounted for in these amounts of time.) Choices A.0.5 RTT B.3.5 RTT C.1.5 RTT D.2.5 RTT E.0 RTT
Suppose within your Web browser you click on a link to obtain a Web page. The IP address for the associated URL isnot cached in your local host, so a DNS lookup is necessary to obtain the IP address. Suppose that n DNS servers arevisited before your host receives the IP address from DNS; the successive visits incur an RTT of RTT1, . . ., RTTn.Further suppose that the Web page associated with the link contains exactly one object, consisting of a small amount ofHTML text. Let RTT0 denote the RTT between the local host and the server containing the object. Assuming zerotransmission time of the object, how much time elapses from when the client clicks on the link until the client receivesthe object?
Write a snort rule to generate an alert for the following: search for the word “HTTP” in the first 20bytes of the payload of a packet that is originating in subnet (192.168.34.0/24) and going toyour subnet (192.168.56.0/24). The alert should read: “HTTP detected”. Could you please also include the nmap command used to scan the target?
Suppose that the RTT delay between a client and an HTTP server is 30 msecs; the time a server needs totransmit an object into its outgoing link is 0.85 msecs; and any other HTTP message not containing an objecthas a negligible (zero) transmission time. Suppose the client again makes 100 requests, one after the other,waiting for a reply to a request before sending the next request.Assume the client is using HTTP 1.1 and the IF-MODIFIED-SINCE header line. Assume 50% of the objectsrequested have NOT changed since the client downloaded them (before these 90 downloads are performed)How much time elapses (in milliseconds) between the client transmitting the first request, and the completionof the last request?