DNS server, DNS server, default port 53, UDP transport protocol, the job server, the domain name to turn ip, ip converted into the domain
sql server default port: 1433, MSSQL is shorthand for sql server
netstat -ano | findstr port number: whether the query system has opened a port
ftp.ichunqiu.com .: fully qualified domain name. "" root domain, "com" top-level domain, 'qichunqiu' second-level domain, "ftp" hostname
Domain search process to find the browser cache -> check their hosts file -> local DNS server -> root name server -> Top-Level Domain -> second-level domain -> find
DNS server requirements
1, configure a static ip
2, pointing to their own preferred DNS
3, optional gateway
DNS client requirements
1, Ip can be statically or dynamically acquire
2, the preferred DNS server must point to DNS
A, AAA master record, recording the FQDN to an IP imply
PTR pointer IP to the recording of cue FQDN
CNAME alias host record recording alias, url alias
MX records messages crossing
DNS working process, reverse lookup, forward queries
forward queries
recursively, PC users query the local DNS server is recursive (have to go back there)
iteration, the local DNS server are iterative queries to other
web site access method
based access method Ip address, the default port 80 when, in this way set up a web server is only one current environment
based on ip + port access method, more ports can be used to build a web server and can be multiple, to access the http: // ip: port
-based access method host headers, DNS server is required to support, access is required domain name + port
HTML+CSS+JavaScript
HTML: HyperText Markup Language, not into language, markup language, the display data, HTML not case sensitive
<: Start
>: End
ditag: YES began end <body> </ body>
Single Label: single unpaired dual appear <img src = # />
parse html code through the browser, the data in the <body> </ body> is displayed
<DOCTYPE html!>: expressed as HTML language
<html> </ html>: the outermost
<head> head start, is used to modify the data
<title> </ title>: title
</ had>: head end
<body> </ body>: main data
<! --- --->: comment
Common HTML tags
<h1> --- <h6>: title, there are six of the title
<hr>: horizontal
<br>: Wrap
<p> </ p>: Paragraph automatically wrap between tags, paragraph
<a href = "url"> want to display text or image </a>: hyperlink
<img src = "url" width = "100" height = "100">: image tag, to tell what the picture by src, width image width, height, height of the image
Table
<table> </ table>: Form