📄 vlan8.htm
字号:
ol
{margin-bottom:0cm;}
ul
{margin-bottom:0cm;}
-->
</style>
<!--[if gte mso 10]>
<style>
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:普通表格;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.0pt;
font-family:"Times New Roman";}
table.MsoTableGrid
{mso-style-name:网格型;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
border:solid windowtext 1.0pt;
mso-border-alt:solid windowtext .5pt;
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-border-insideh:.5pt solid windowtext;
mso-border-insidev:.5pt solid windowtext;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
text-align:justify;
text-justify:inter-ideograph;
mso-pagination:none;
font-size:10.0pt;
font-family:"Times New Roman";}
</style>
<![endif]--><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="3074" fill="f" fillcolor="red">
<v:fill color="red" on="f"/>
<v:stroke weight="1pt"/>
</o:shapedefaults></xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1,2"/>
<o:rules v:ext="edit">
<o:r id="V:Rule81" type="callout" idref="#_x0000_s2314"/>
</o:rules>
<o:regrouptable v:ext="edit">
<o:entry new="1" old="0"/>
<o:entry new="2" old="0"/>
<o:entry new="3" old="0"/>
<o:entry new="4" old="0"/>
<o:entry new="5" old="0"/>
<o:entry new="6" old="0"/>
<o:entry new="7" old="0"/>
<o:entry new="8" old="0"/>
<o:entry new="9" old="0"/>
<o:entry new="10" old="0"/>
<o:entry new="11" old="0"/>
<o:entry new="12" old="0"/>
<o:entry new="13" old="0"/>
<o:entry new="14" old="13"/>
<o:entry new="15" old="0"/>
<o:entry new="16" old="0"/>
<o:entry new="17" old="0"/>
<o:entry new="18" old="0"/>
<o:entry new="19" old="0"/>
</o:regrouptable>
</o:shapelayout></xml><![endif]-->
</head>
<body lang=ZH-CN link=blue vlink=purple style='tab-interval:21.0pt;text-justify-trim:
punctuation'>
<div class=Section1 style='layout-grid:15.6pt'>
<p class=MsoNormal align=center style='text-align:center'><b style='mso-bidi-font-weight:
normal'><span style='font-size:14.0pt;font-family:宋体;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>三层交换机（</span></b><b
style='mso-bidi-font-weight:normal'><span lang=EN-US style='font-size:14.0pt'>1</span></b><b
style='mso-bidi-font-weight:normal'><span style='font-size:14.0pt;font-family:
宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"'>）</span></b><b
style='mso-bidi-font-weight:normal'><span lang=EN-US style='font-size:14.0pt'><o:p></o:p></span></b></p>
<p class=MsoNormal><b style='mso-bidi-font-weight:normal'><span
style='font-size:12.0pt;font-family:宋体;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman";color:red'>使用路由器进行</span></b><b
style='mso-bidi-font-weight:normal'><span lang=EN-US style='font-size:12.0pt;
color:red'>VLAN</span></b><b style='mso-bidi-font-weight:normal'><span
style='font-size:12.0pt;font-family:宋体;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman";color:red'>间路由时的问题</span></b><b
style='mso-bidi-font-weight:normal'><span lang=EN-US style='font-size:12.0pt;
color:red'><o:p></o:p></span></b></p>
<p class=MsoNormal align=left style='text-align:left;mso-pagination:widow-orphan'><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>现在，我们知道只要能提供</span><span lang=EN-US>VLAN</span><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>间路由，就能够使分属不同</span><span lang=EN-US>VLAN</span><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>的计算机互相通信。但是，如果使用路由器进行</span><span lang=EN-US>VLAN</span><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>间路由的话，<span style='color:red'>随着</span></span><span
lang=EN-US style='color:red'>VLAN</span><span style='font-family:宋体;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman";color:red'>之间流量的不断增加，很可能导致路由器成为整个网络的瓶颈</span><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>。</span></p>
<p class=MsoNormal align=left style='text-align:left;mso-pagination:widow-orphan'><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>交换机使用被称为</span><span lang=EN-US>ASIC</span><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>（</span><span lang=EN-US>Application Specified Integrated
Circuit</span><span style='font-family:宋体;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>）的专用硬件芯片处理数据帧的交换操作，在很多机型上都能实现以缆线速度（</span><span
lang=EN-US>Wired Speed</span><span style='font-family:宋体;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>）交换。而路由器，则基本上是基于软件处理的。即使以缆线速度接收到数据包，也无法在不限速的条件下转发出去，因此会成为速度瓶颈。就</span><span
lang=EN-US>VLAN</span><span style='font-family:宋体;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>间路由而言，<span style='color:red'>流量会集中到路由器和交换机互联的汇聚链路部分</span>，这一部分尤其特别容易成为速度瓶颈。并且从硬件上看，由于需要分别设置路由器和交换机，<span
style='color:red'>在一些空间狭小的环境里可能连设置的场所都成问题</span>。</span></p>
<p class=MsoNormal align=left style='text-align:left;mso-pagination:widow-orphan'><span
lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal align=left style='text-align:left;mso-pagination:widow-orphan'><b
style='mso-bidi-font-weight:normal'><span style='font-size:12.0pt;font-family:
宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman";
color:red'>三层交换机（</span></b><b style='mso-bidi-font-weight:normal'><span
lang=EN-US style='font-size:12.0pt;color:red'>Layer 3 Switch</span></b><b
style='mso-bidi-font-weight:normal'><span style='font-size:12.0pt;font-family:
宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman";
color:red'>）</span></b><b style='mso-bidi-font-weight:normal'><span lang=EN-US
style='font-size:12.0pt;color:red'><o:p></o:p></span></b></p>
<p class=MsoNormal align=left style='text-align:left;mso-pagination:widow-orphan'><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>为了解决上述问题，三层交换机应运而生。<span style='color:blue'>三层交换机，本质上就是“带有路由功能的（二层）交换机”</span>。路由属于</span><span
lang=EN-US>OSI</span><span style='font-family:宋体;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"'>参照模型中第三层网络层的功能，因此带有第三层路由功能的交换机才被称为“三层交换机”。</span></p>
<p class=MsoNormal align=left style='text-align:left;mso-pagination:widow-orphan'><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>关于三层交换机的内部结构，可以参照下面的简图。</span></p>
<p class=MsoNormal align=left style='text-align:left;mso-pagination:widow-orphan'><!--[if mso & !supportInlineShapes & supportFields]><span
lang=EN-US><span style='mso-element:field-begin;mso-field-lock:yes'></span><span
style='mso-spacerun:yes'> </span>SHAPE<span
style='mso-spacerun:yes'> </span>\* MERGEFORMAT <span style='mso-element:
field-separator'></span></span><![endif]--><span lang=EN-US><!--[if gte vml 1]><v:group
id="_x0000_s2308" editas="canvas" style='width:414pt;height:218.4pt;
mso-position-horizontal-relative:char;mso-position-vertical-relative:line'
coordorigin="2355,6108" coordsize="7200,3804">
<o:lock v:ext="edit" aspectratio="t"/>
<v:shapetype id="_x0000_t75" coordsize="21600,21600" o:spt="75"
o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f">
<v:stroke joinstyle="miter"/>
<v:formulas>
<v:f eqn="if lineDrawn pixelLineWidth 0"/>
<v:f eqn="sum @0 1 0"/>
<v:f eqn="sum 0 0 @1"/>
<v:f eqn="prod @2 1 2"/>
<v:f eqn="prod @3 21600 pixelWidth"/>
<v:f eqn="prod @3 21600 pixelHeight"/>
<v:f eqn="sum @0 0 1"/>
<v:f eqn="prod @6 1 2"/>
<v:f eqn="prod @7 21600 pixelWidth"/>
<v:f eqn="sum @8 21600 0"/>
<v:f eqn="prod @7 21600 pixelHeight"/>
<v:f eqn="sum @10 21600 0"/>
</v:formulas>
<v:path o:extrusionok="f" gradientshapeok="t" o:connecttype="rect"/>
<o:lock v:ext="edit" aspectratio="t"/>
</v:shapetype><v:shape id="_x0000_s2307" type="#_x0000_t75" style='position:absolute;
left:2355;top:6108;width:7200;height:3804' o:preferrelative="f">
<v:fill o:detectmouseclick="t"/>
<v:path o:extrusionok="t" o:connecttype="none"/>
<o:lock v:ext="edit" text="t"/>
</v:shape><v:rect id="_x0000_s2309" style='position:absolute;left:3920;top:6516;
width:4539;height:2989' filled="f" fillcolor="red" strokecolor="green"
strokeweight="2pt"/>
<v:shapetype id="_x0000_t202" coordsize="21600,21600" o:spt="202" path="m,l,21600r21600,l21600,xe">
<v:stroke joinstyle="miter"/>
<v:path gradientshapeok="t" o:connecttype="rect"/>
</v:shapetype><v:shape id="_x0000_s2310" type="#_x0000_t202" style='position:absolute;
left:2668;top:7467;width:1252;height:407' filled="f" fillcolor="red"
stroked="f" strokeweight="1pt">
<v:textbox>
<![if !mso]>
<table cellpadding=0 cellspacing=0 width="100%">
<tr>
<td><![endif]>
<div>
<p class=MsoNormal><b style='mso-bidi-font-weight:normal'><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman";color:green'>三层交换机</span><span lang=EN-US
style='color:green'><o:p></o:p></span></b></p>
</div>
<![if !mso]></td>
</tr>
</table>
<![endif]></v:textbox>
</v:shape><v:rect id="_x0000_s2311" style='position:absolute;left:4859;top:6787;
width:2661;height:680' filled="f" fillcolor="red" strokecolor="red"
strokeweight="1pt">
<v:textbox>
<![if !mso]>
<table cellpadding=0 cellspacing=0 width="100%">
<tr>
<td><![endif]>
<div>
<p class=MsoNormal align=center style='text-align:center'><b
style='mso-bidi-font-weight:normal'><span style='font-family:宋体;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman";
color:red'>路由模块</span><span lang=EN-US style='color:red'><o:p></o:p></span></b></p>
</div>
<![if !mso]></td>
</tr>
</table>
<![endif]></v:textbox>
</v:rect><v:rect id="_x0000_s2312" style='position:absolute;left:4546;top:8146;
width:3444;height:952' filled="f" fillcolor="red" strokecolor="blue"
strokeweight="1pt">
<v:textbox>
<![if !mso]>
<table cellpadding=0 cellspacing=0 width="100%">
<tr>
<td><![endif]>
<div>
<p class=MsoNormal align=center style='text-align:center'><b
style='mso-bidi-font-weight:normal'><span style='font-family:宋体;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman";
color:blue'>交换模块</span><span lang=EN-US style='color:blue'><o:p></o:p></span></b></p>
</div>
<![if !mso]></td>
</tr>
</table>
<![endif]></v:textbox>
</v:rect><v:line id="_x0000_s2313" style='position:absolute' from="6268,7467"
to="6269,8146" strokecolor="#f60" strokeweight="3.5pt"/>
<v:shapetype id="_x0000_t47" coordsize="21600,21600" o:spt="47" adj="-8280,24300,-1800,4050"
path="m@0@1l@2@3nfem,l21600,r,21600l,21600xe">
<v:stroke joinstyle="miter"/>
<v:formulas>
<v:f eqn="val #0"/>
<v:f eqn="val #1"/>
<v:f eqn="val #2"/>
<v:f eqn="val #3"/>
</v:formulas>
<v:path arrowok="t" o:extrusionok="f" gradientshapeok="t" o:connecttype="custom"
o:connectlocs="@0,@1;10800,0;10800,21600;0,10800;21600,10800"/>
<v:handles>
<v:h position="#0,#1"/>
<v:h position="#2,#3"/>
</v:handles>
<o:callout v:ext="edit" type="oneSegment" on="t"/>
</v:shapetype><v:shape id="_x0000_s2314" type="#_x0000_t47" style='position:absolute;
left:6738;top:7602;width:1565;height:408' adj="-6624,13385,-1440,8308,4320,-10154,4320,-10154"
filled="f" fillcolor="red" strokecolor="#f60" strokeweight="1pt">
<v:textbox>
<![if !mso]>
<table cellpadding=0 cellspacing=0 width="100%">
<tr>
<td><![endif]>
<div>
<p class=MsoNormal><b style='mso-bidi-font-weight:normal'><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman";color:#FF6600'>内部是汇聚链路</span><span lang=EN-US
style='color:#FF6600'><o:p></o:p></span></b></p>
</div>
<![if !mso]></td>
</tr>
</table>
<![endif]></v:textbox>
<o:callout v:ext="edit" minusy="t"/>
</v:shape><v:rect id="_x0000_s2316" style='position:absolute;left:4859;top:8690;
width:313;height:270' filled="f" fillcolor="red" strokeweight="1pt"/>
<v:rect id="_x0000_s2317" style='position:absolute;left:5485;top:8690;width:313;
height:270' filled="f" fillcolor="red" strokeweight="1pt"/>
<v:rect id="_x0000_s2318" style='position:absolute;left:6112;top:8690;width:313;
height:270' filled="f" fillcolor="red" strokeweight="1pt"/>
<v:rect id="_x0000_s2319" style='position:absolute;left:6738;top:8690;width:313;
height:270' filled="f" fillcolor="red" strokeweight="1pt"/>
<v:rect id="_x0000_s2320" style='position:absolute;left:7364;top:8690;width:313;
height:270' filled="f" fillcolor="red" strokeweight="1pt"/>
<w:wrap type="none" side="left"/>
<w:anchorlock/>
</v:group><![endif]--><![if !vml]><img width=552 height=291
src="VLAN8.files/image001.gif" v:shapes="_x0000_s2308 _x0000_s2307 _x0000_s2309 _x0000_s2310 _x0000_s2311 _x0000_s2312 _x0000_s2313 _x0000_s2314 _x0000_s2316 _x0000_s2317 _x0000_s2318 _x0000_s2319 _x0000_s2320"><![endif]></span><!--[if mso & !supportInlineShapes & supportFields]><span
lang=EN-US><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:414pt;
height:218.4pt'>
<v:imagedata croptop="-65520f" cropbottom="65520f"/>
</v:shape><span style='mso-element:field-end'></span></span><![endif]--></p>
<p class=MsoNormal align=left style='text-align:left;mso-pagination:widow-orphan'><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"'>在一台本体内，分别设置了交换机模块和路由器模块；而内置的路由模块与交换模块相同，<span
style='color:blue'>使用</span></span><span lang=EN-US style='color:blue'>ASIC</span><span
style='font-family:宋体;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman";color:blue'>硬件处理路由</span><span style='font-family:宋体;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"'>。因此，与传统的路由器相比，可以实现高速路由。并且，<span
style='color:blue'>路由与交换模块是汇聚链接的</span>，由于是内部连接，可以确保相当大的带宽。</span></p>
</div>
</body>
</html>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -