DNS settings error, the browser can access the site properly?

Everyone is seeing this problem, the first reaction is not all think: Can't?

Hey, I knew everyone's normal thinking is also the case.

At first I thought it was supposed to be like this, but one thing that happened to me a while ago was that I changed this idea:

the previous time the computer room DHCP service shutdown, we must not have started to use static IP, at this time because the teacher did not say that the DNS server on another machine, we take it for granted that the DNS IP is the original DHCP IP, because we are using 360 browser, I found that setting up a static IP does not affect our normal online search data. Since the 51cto video can not see, ask the teacher why, the teacher looked at the IP said DNS settings error. The teacher returned to normal as soon as he changed. I was confused, the DNS settings error will not resolve the domain name, how can you still log on to the site? Then asked the teacher on this question, the teacher was also very surprised, began to use the grab Bag tool for detection: open IE and 360, the DNS deliberately set errors, grab the package tool to see, ie very rules in accordance with my DNS to find the domain name to resolve, and 360 direct access to 51cto IP address. When I saw this, the teacher was blindfolded. He was also confused about how the 360 tools would go directly to the site's IP.
after home also tested some, with the IE, travel, 360 rapid version. DNS is still deliberately set errors, the results found that only 360 of the rapid access to the site, the remaining two browsers are inaccessible.

Let's not go into the principle of what it is, let's test it out first.

Our general environment is used by DHCP to assign Ip,dns.

Before the experiment, we set the DNS to: Primary DNS:1.2.3.4, secondary DNS:5.6.7.8

Browser: I use ie,firefox,chrome, Baidu, 360,opera These six browsers to test.

There are certain reasons why they are chosen.

We all know the three major browser cores:

IEOfTrident，FirefoxOfGecko and chrome webkit (now seemingly improved for blink ).

> They were chosen to verify that the browser's kernel had DNS built-in settings, while the other three models were more representative of three, opera performance, the speed of a good browser, 360 is the main focus of security, Baidu , just a person's preference.

the , Baidu 's browser kernel is a two-time development based on open source WebKit. ( Please correct me if you are wrong )

Experiment started.

Preparatory work:

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/47/D7/wKioL1QATIbD-ftMAAF3669_Rs8038.jpg "title=" Dns1.jpg "alt=" Wkiol1qatibd-ftmaaf3669_rs8038.jpg "/>

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/47/D5/wKiom1QAS2_zsFyuAAHeAwJ_Jqw476.jpg "title=" Dns2.jpg "alt=" Wkiom1qas2_zsfyuaaheawj_jqw476.jpg "/>

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/47/D7/wKioL1QAT5vBPXz-AAOHM0r9ldA530.jpg "title=" Dns.jpg "alt=" Wkiol1qat5vbpxz-aaohm0r9lda530.jpg "/>

We mainly analyze DNS, so we look at the time to filter out the other packets. Focus only on DNS

Experiment begins:

Open the Wireshark capture process

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/47/D7/wKioL1QATIbyU8MnAAJB0Bqh0oY866.jpg "title=" Dns3.jpg "alt=" Wkiol1qatibyu8mnaajb0bqh0oy866.jpg "/>

Select the network card class that is connected to the extranet , then click Start

Test the Ie,chrome,firefox First: enter the 51cto URL

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/47/D7/wKioL1QATIfwGhhyAADdTnA2hPo335.jpg "title=" Dns4.jpg "alt=" Wkiol1qatifwghhyaaddtna2hpo335.jpg "/>

IE failed to open web page

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/49/D2/wKioL1QblNKRInJhAAC5_-7_nRw300.jpg "title=" Dns1.jpg "alt=" Wkiol1qblnkrinjhaac5_-7_nrw300.jpg "/>

Google load Process

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/49/D0/wKiom1QblLjTaK6SAABpr4NjFIQ507.jpg "title=" Dns2.jpg "alt=" Wkiom1qblljtak6saabpr4njfiq507.jpg "/>

Web page could not be opened

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/4A/2B/wKioL1QjhsbzlJNnAALp8uMO0Js580.jpg "title=" Snap010.jpg "width=" "height=" 378 "border=" 0 "hspace=" 0 "vspace=" 0 "alt=" wkiol1qjhsbzljnnaalp8umo0js580.jpg "style = "width:700px;height:378px;"/>

Firefox loading process

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/4A/2B/wKioL1Qjhsei9sbVAAMK96rFy1o222.jpg "title=" Snap011.jpg "width=" "height=" 378 "border=" 0 "hspace=" 0 "vspace=" 0 "alt=" wkiol1qjhsei9sbvaamk96rfy1o222.jpg "style = "width:700px;height:378px;"/>

Firefox failed to open web page

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/4A/2B/wKioL1QjhsnwkR4gABEnvnaZlXc898.jpg "title=" Snap012.jpg "width=" "height=" 405 "border=" 0 "hspace=" 0 "vspace=" 0 "alt=" wkiol1qjhsnwkr4gabenvnazlxc898.jpg "style = "width:700px;height:405px;"/>

Test Result: failed .

The representatives of these three cores are really, in the case of DNS settings error, honestly follow the wrong DNS I set up to find the corresponding domain name. The Web page was not able to open. (In fact, all three of the DNS packets are the same, so they are represented by a graph)

Test the Opera browser below: Enter the 51cto URL

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/4A/2B/wKioL1QjhsCgyuW_AAHZgQoOWIs723.jpg "style=" width : 700px;height:393px; "title=" snap005.jpg "width=" "height=" "393" border= "0" hspace= "0" vspace= "0" alt= " Wkiol1qjhscgyuw_aahzgqoowis723.jpg "/>

Loading Process

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/4A/29/wKiom1QjhpzQILTCAAHE4Di2o9k243.jpg "style=" width : 700px;height:393px; "title=" snap006.jpg "width=" "height=" "393" border= "0" hspace= "0" vspace= "0" alt= " Wkiom1qjhpzqiltcaahe4di2o9k243.jpg "/>

end of load, failed to open web page

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/4A/29/wKiom1Qjhp7yEFJyABFX6E-hPLs814.jpg "style=" width : 700px;height:405px; "title=" snap007.jpg "width=" "height=" "405" border= "0" hspace= "0" vspace= "0" alt= " Wkiom1qjhp7yefjyabfx6e-hpls814.jpg "/>

Conclusion: failure . Opera is still a very real browser, still in accordance with my settings to query. It's a pity.

The following began to test Baidu: enter the 51cto URL

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/4A/29/wKiom1QjhqeifbNWAAmUMqSvJ54411.jpg "style=" width : 700px;height:378px; "title=" snap014.jpg "width=" "height=" "378" border= "0" hspace= "0" vspace= "0" alt= " Wkiom1qjhqeifbnwaamumqsvj54411.jpg "/>

Perfect Loading

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/4A/2B/wKioL1QjhsyBpP5WAAsCZC-Qxzs092.jpg "style=" width : 700px;height:378px; "title=" snap015.jpg "width=" "height=" "378" border= "0" hspace= "0" vspace= "0" alt= " Wkiol1qjhsybpp5waasczc-qxzs092.jpg "/>

Baidu opens web page successfully

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/4A/29/wKiom1QjhqrANugUABDWcuJm5sg860.jpg "style=" width : 700px;height:405px; "title=" snap016.jpg "width=" "height=" "405" border= "0" hspace= "0" vspace= "0" alt= " Wkiom1qjhqranuguabdwcujm5sg860.jpg "/>

at first, honestly, read the rules I set for DNS

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/4A/2B/wKioL1QjhtDz2zkxABITHffuM3g164.jpg "style=" width : 700px;height:405px; "title=" snap017.jpg "width=" "height=" "405" border= "0" hspace= "0" vspace= "0" alt= " Wkiol1qjhtdz2zkxabithffum3g164.jpg "/>

the diagram appears 144.144.144.144.

I paid two of its HTTP packets below everyone is interested to see, I do not see anything special place.

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/4A/2B/wKioL1QjhtKiOwyTABMTI6mSeMs057.jpg "style=" width : 700px;height:405px; "title=" snap018.jpg "width=" "height=" "405" border= "0" hspace= "0" vspace= "0" alt= " Wkiol1qjhtkiowytabmti6msems057.jpg "/>

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/4A/29/wKiom1QjhrDTbZeDABHK60AswVw260.jpg "style=" width : 700px;height:405px; "title=" snap019.jpg "width=" "height=" "405" border= "0" hspace= "0" vspace= "0" alt= " Wkiom1qjhrdtbzedabhk60aswvw260.jpg "/>

Conclusion: success . We can find through the DNS package, at first Baidu is also honest according to the DNS I set up the domain name query, it was not long before suddenly jumped out of the public dns:144.144.144.144. What's the situation? Let's not discuss it first.

Let's take a look at the 360 performance.

is still input 51cto website

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/4A/29/wKiom1QjhraD_YOXAAcn6pXVXsQ967.jpg "style=" width : 700px;height:378px; "title=" snap021.jpg "alt=" wkiom1qjhrad_yoxaacn6pxvxsq967.jpg "width=" to "height=" 378 "border= "0" hspace= "0" vspace= "0"/>

The Web page opens, but the picture is not visible, the loading is not perfect

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/4A/29/wKiom1QjhreQDMrgAAp1ZnuWsmw872.jpg "style=" width : 700px;height:378px; "title=" snap022.jpg "alt=" wkiom1qjhreqdmrgaap1znuwsmw872.jpg "width=" to "height=" 378 "border= "0" hspace= "0" vspace= "0"/>

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/4A/2B/wKioL1Qjht3A0kINABFEuPfUWEE303.jpg "style=" width : 700px;height:405px; "title=" snap023.jpg "alt=" wkiol1qjht3a0kinabfeupfuwee303.jpg "width=" to "height=" 405 "border= "0" hspace= "0" vspace= "0"/>

At first, it's still the rules.

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/4A/2B/wKioL1QjhuOwsQv4ABD8c3Ug_7c134.jpg "style=" width : 700px;height:405px; "title=" snap025.jpg "alt=" wkiol1qjhuowsqv4abd8c3ug_7c134.jpg "width=" to "height=" 405 "border= "0" hspace= "0" vspace= "0"/>

this picture appears. Public IP:8.8.8.8

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/4A/2B/wKioL1QjhuqQ83YqABDbLByzfto801.jpg "style=" width : 700px;height:405px; "title=" snap027.jpg "alt=" wkiol1qjhuqq83yqabdblbyzfto801.jpg "width=" to "height=" 405 "border= "0" hspace= "0" vspace= "0"/>

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/4A/2B/wKioL1QjhvDDXYHSABFZgrv6Jr4383.jpg "style=" width : 700px;height:405px; "title=" snap029.jpg "alt=" wkiol1qjhvddxyhsabfzgrv6jr4383.jpg "width=" to "height=" 405 "border= "0" hspace= "0" vspace= "0"/>

below also for 360 paid an HTTP Capture package diagram.

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/4A/29/wKiom1Qjhs_R0AWDABS12t-IOHI726.jpg "style=" width : 700px;height:405px; "title=" snap030.jpg "alt=" wkiom1qjhs_r0awdabs12t-iohi726.jpg "width=" to "height=" 405 "border= "0" hspace= "0" vspace= "0"/>

Conclusion: success . At first 360 was also honestly in accordance with the DNS I set up the domain name query, not long, but also suddenly pop out a public dns:8.8.8.8

Experiment Summary:

Ie,chrome,firefox,opera all failed . Baidu, success .

The failure of Ie,chrome,firefox rejected the possibility that the browser kernel set up DNS.

Baidu, 360 success proves that this feature was developed independently by him or by them.

The results of the experiment may be a big surprise to everyone. The least favored two browsers are not affected by the DNS settings error in the case of access to the site, why?

At first I was also very confused about it, checked 360 all the update patch description also did not find a DNS related instructions, Baidu is also.

After the forum post, did not expect a few experts to reply

Their answer is as follows

You deliberately set the DNS server address wrong, so you don't have a chance to access 51cto.

However, please note that 360 Security browser is a secure browser, as a browser is the most taboo is the occurrence of DNS hijacking this will fundamentally disrupt the security mechanism of 360. In other words, if the local settings are read as the default DNS, then if this DNS is hijacked (that is, I can putwww.baidu.com, point to any of my fake IP addresses or websites) then even if the 360 browser is no longer a cow, there is no way to keep the user safe. In this regard, 360 must be built into a secure DNS server, directly using the 360 built-in DNS IP to resolve addresses or as a means of being hijacked than DNS. Thus. The problem inevitably occurs on 360 browsers. To say more, DNS only provides the domain name resolution function . So, if you use the IP address directly to access, even if you do not have DNS as you can get. So if 360 built a more just DNS IP address, and then all the 360 browser access has this IP to resolve, only 360 can surf the internet is no problem.

I read a little bit, and then asked the others. Came to a more convincing answer at present.

360 and Baidu are in the open source browser core on the 2 Development and optimization (it is obvious that Baidu's optimization to do more perfect point), think most people in China do not understand the DNS, let alone set up. So they think of simply our browser to help you solve this problem. They then wrote the corresponding strategy, that is, when the local DNS server does not provide the normal service, the DNS is assigned to the more just and secure DNS they set up to resolve the domain name. Then there is the result we see above. Before a lot of people to 360 a little resistance, in fact, 360 of the browser is still reliable. (Really not for 360 advertising AH) but this two browser internal policy or the kernel is not so I do not know, if 360, Baidu browser developers See, also please explain. This is the most convincing answer I have now summed up. We have different opinions to exchange.

PS: I find that if we look at life carefully, we can still find a lot of interesting questions.

This article is from "Zhang Fan-it's fantasy drifting" blog, please be sure to keep this source http://chawan.blog.51cto.com/9179874/1558074

DNS settings error, the browser can access the site properly?