📄 riptheory.htm
字号:
<html>
<head>
<meta http-equiv="Content-Language" content="en-us">
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<meta name="GENERATOR" content="Microsoft FrontPage 5.0">
<meta name="ProgId" content="FrontPage.Editor.Document">
<title>New Page 1</title>
</head>
<body>
<script language="Javascript">
<!--
function printpage() {
if (window.print)
window.print()
else
alert("Sorry, your browser doesn't support this feature.");
}
//-->
</script>
<FORM>
<INPUT TYPE="button" VALUE="Print this page" onClick="printpage()">
</FORM>
<p><font face="Arial"><i>Prerequisites</i>: To start this lab you need to have a connection to
eRouter1, eRouter2, and eRouter4. </font></p>
<p><font face="Arial"><i>Goals</i>: </font></p>
<p><font face="Arial">1) Set our hostname and get our interfaces up.</font></p>
<p><font face="Arial">2) Configure RIP routing protocol</font></p>
<p><font face="Arial">3) Select the directly connected networks</font></p>
<p><font face="Arial">4) View our routing table</font></p>
<p><font face="Arial">5) View the RIP protocol information</font></p>
<p><font face="Arial">6) Observe RIP debugging information</font></p>
<p><font face="Arial">IP Addresses: Please set these IP addresses on the interfaces of your
routers.</font></p>
<table border="0" width="100%">
<tr>
<td width="25%"></td>
<td width="25%">eRouter1</td>
<td width="25%">eRouter2</td>
<td width="25%">eRouter4</td>
</tr>
<tr>
<td width="25%">Interface Ethernet 0</td>
<td width="25%">10.1.1.1 255.255.255.0</td>
<td width="25%">10.1.1.2 255.255.255.0</td>
<td width="25%"> </td>
</tr>
<tr>
<td width="25%">Interface Serial 0</td>
<td width="25%">172.16.10.1 255.255.0.0</td>
<td width="25%"> </td>
<td width="25%">172.16.10.2 255.255.0.0</td>
</tr>
</table>
<hr align="center">
<p><b><font face="Arial" size="4" color="#008000">Routing Information Protocol
(RIP)</font></b></p>
<p><font face="Arial">Routing Information Protocol (RIP) is a standards-based, distance-vector,
interior gateway protocol (IGP) used by routers to exchange routing
information. RIP uses hop count to determine the best path between two
locations. Hop count is the number of routers the packet must go through
till it reaches the destination network. The maximum allowable number of hops a packet can traverse in
an IP network implementing RIP is 15 hops. In a RIP network, each router
broadcasts its entire RIP table to its neighboring routers every 30
seconds. When a router receives a neighbor's RIP table, it uses the
information provided to update its own routing table and then sends the updated
table to its neighbors. This procedure is repeated by each router and results in
a state referred to as network convergence, in which all routers have an
identical view of the internetwork topology.</font></p>
<p><font face="Arial">Lets connect to eRouter1 and get it configured. We
will be using the table above for our IP addresses.</font><font color="#FF0000" face="Arial"><br>
</font><font color="#FF0000" face="Courier"> <br>
</font><font face="Terminal" size="2">Router>en<br>
Router#conf t<br>
Enter configuration commands, one per line. End with CNTL/Z. <br>
Router(config)#hostname eRouter1<br>
eRoute1r(config)#int e0<br>
eRouter1(config-if)#ip address 10.1.1.1 255.255.255.0<br>
eRouter1(config-if)#no shut<br>
%LINK-3-UPDOWN: Interface Ethernet0, changed state to up </font><font face="Terminal" size="2"><br>
eRouter1(config-if)#exit <br>
<br>
eRouter1(config)#int s0<br>
eRouter1(config-if)#ip address 172.16.10.1 255.255.0.0<br>
eRouter1(config-if)#no shut<br>
%LINK-3-UPDOWN: Interface Serial0, changed state to up<br>
%LINK-3-UPDOWN: Interface Serial0, changed state to down <br>
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to down<br>
eRouter1(config-if)#exit <br>
eRouter1(config)# </font><font color="#FF0000" face="Times New Roman"><br>
</font> </p>
<p> </p>
<p><font face="Arial">RIP version 1 is <b>classful</b>, meaning it does not include the subnet mask in its
routing table updates. RIP version 2 is classless and includes the subnet
information. Now lets go ahead and start the lab.</font></p>
<p><font face="Arial">1. We first want to configure eRouter1 for RIP. To enable RIP as the routing protocol we only need to type: </font>
<font face="Terminal" size="2">router
rip</font><font face="Arial"> We can see this below in the router output.
Notice the new mode we have entered </font><font face="Terminal" size="2">
eRouter1(config-router)#</font><font face="Arial"> that tells us we are
configuring the router. </font></p>
<p><font face="Courier" color="#FF0000">
<br>
</font><font face="Terminal" size="2">
eRouter1(config)#router rip<br>
eRouter1(config-router)#</font></p>
<p><b><font face="Arial" size="4" color="#008000">Network Statements / Network
Numbers</font></b></p>
<p><font face="Arial">Now that we have RIP running on our Router we need to tell the router which
networks it is connected to. We do this by using the network statement.
What this means is every interface of our router that is directly connected to an
active network needs a network number. We will have some networks using the same ip addressing
schemes with different subnets, and some are using entirely different addressing
schemes. Look at the diagram below. In this diagram we have three
different kinds of addressing schemes. Lets look at these in more
detail. On eRouter 1 we have an IP address of 10.1.1.1 with a /24 subnet
mask. Since RIP is classful you are only required to enter the class part
of the address for the network statement. For example on eRouter1 we have
already issued the command router rip, we then need to specify the directly
connected networks to eRouter1 so the router can advertise these routes in its routing table. To do this we would only need to type: </font>
<font face="Terminal" size="2">network
10.0.0.0</font><font face="Arial"> now we have not told the router about the network
on its serial interface, to do this we would type: </font>
<font face="Terminal" size="2">network
172.16.0.0</font><font face="Arial"> Lets look at eRouter 2, what network statements would you need to use on this router ______________________________________(see
the answer below the diagram.) </font> </p>
<p> </p>
<p>
<img border="0" src="default.jpg" width="599" height="579"></p>
<p><font face="Arial">The answers are </font>
<font face="Terminal" size="2">network 10.0.0.0</font><font face="Arial">. The network statement for the serial link is the same for eRouter1
and eRouter2. For the network statement for the Ethernet link you
had to remember that a 192 address was a class C address, for this network
statement you used the classful portion of the address 192.168.1.0.</font></p>
<p><font face="Arial">Now that we understand the network command lets enter it on our eRouter1.</font></p>
<p><font face="Courier" color="#FF0000"><br>
</font><font face="Terminal" size="2">eRouter1(config-router)#network 172.16.0.0<br>
eRouter1(config-router)#network 10.0.0.0<br>
eRouter1(config-router)#</font></p>
<p><font face="Arial">If you notice we only entered 10.0.0.0 for our network statement, this is
because 10.0.0.0 is a Class A address and RIP only uses the classful portion
of the address. Now we have configured eRouter1 for RIP lets connect to
eRouter2 and get it setup.</font></p>
<p><font face="Arial"> We need to
connect to eRouter2 and follow the same instructions. Lets select eRouter2
from the Window pull down menu. When we connect we are going to set the hostname to eRouter2, then set the
IP addresses to the table above and configure
RIP. </font> </p>
<p><font color="#FF0000" face="Courier"><br>
</font><font face="Terminal" size="2">Router>en<br>
Router#conf t<br>
Enter configuration commands, one per line. End with CNTL/Z.<br>
Router(config)#hostname eRouter2<br>
eRouter2(config)#int e0<br>
eRouter2(config-if)#ip address 10.1.1.2 255.255.255.0<br>
eRouter2(config-if)#no shut<br>
00:17:25: %LINK-3-UPDOWN: Interface Ethernet0, changed state to up </font><font face="Terminal" size="2"><br>
eRouter2(config-if)#exit<br>
eRouter2(config)#</font></p>
<p><font face="Arial">Now add the RIP stuff!</font></p>
<p><font size="2" color="#FF0000" face="Terminal"><br>
</font><font size="2" face="Terminal">eRouter2(config)#router rip<br>
eRouter2(config-router)#network 10.0.0.0<br>
eRouter2(config-router)#exit<br>
eRouter2(config)#exit<br>
eRouter2#</font></p>
<p><font face="Arial">We should now have RIP running on our network between eRouter1 and eRouter2.
Now we need to get eRouter4 setup.</font></p>
<p><font face="Arial">We need to
connect to eRouter4 and follow the same instructions. Lets select eRouter4
from the Window pull down menu. When we connect we are going to set the hostname to
eRouter4, then set the IP addresses to the table above and configure
RIP. </font></p>
<p><font color="#FF0000" face="Courier"><br>
</font><font face="Terminal" size="2">Router>en<br>
Router#conf t<br>
Enter configuration commands, one per line. End with CNTL/Z.<br>
Router(config)#hostname eRouter4<br>
eRouter4(config)#int s0<br>
eRouter4(config-if)#ip address 172.16.10.2 255.255.0.0<br>
eRouter4(config-if)#no shut<br>
00:20:35: %LINK-3-UPDOWN: Interface Serial0, changed state to up <br>
eRouter4(config-if)#exit<br>
eRouter4(config)#</font></p>
<p><font face="Arial">Now add the RIP stuff!</font></p>
<p><font color="#FF0000" face="Courier"> </font><font face="Terminal" size="2">eRouter4(config)#router
rip<br>
eRouter4(config-router)#network 172.16.0.0<br>
eRouter4(config-router)#exit<br>
eRouter4(config)#exit<br>
eRouter4#</font></p>
<p><b><font face="Arial" size="4" color="#008000">Show Commands</font></b></p>
<p><font face="Arial"> Now that we have RIP running on our entire network lets verify that it is receiving routes.
To do this we will be using some show commands. The most common one is </font>
<font face="Terminal" size="2">show ip route</font><font face="Arial">. This displays all entries in the routing table. If we do
this on our eRouter 4 we will see the route to our directly connected eRouter1, we
will also see routes to the other routers we have setup on the network.
Lets take a look at our routing table, to do this type: </font>
<font face="Terminal" size="2">show
ip route</font><font face="Arial"> from the privilege mode.</font></p>
<p><font face="Arial">Lets look at the first entry </font>
<font face="Terminal" size="2">R 10.1.1.0/24 [120/1] via
172.16.10.2, 00:00:21, Serial0</font><font face="Arial">. It starts off with </font>
<font face="Terminal" size="2">R</font><font face="Arial"> this says it
is a RIP route, it then says the destination
network with subnet mask in this case it is 10.1.1.0 with a /24 (255.255.255.0)
subnet mask. Next it gives 120/1, the 120 is the administrative distance, RIP's default administrative distance is 120. Administrative distance is
considered the trustworthiness of the route. If you have two routing protocols
with the same route the router will pick the route with the lower number.
The 1 is the hops required to get to the destination network. The next
piece of information is the via 172.16.10.1 that is the next hop address it must go
to. The last item is that this information was learned via
Serial0. </font></p>
<p><font face="Arial">Another great command is </font>
<font face="Terminal" size="2">show ip protocols</font><font face="Arial">. This displays information
about the IP routing protocols you have enabled. Lets type the command : </font>
<font face="Terminal" size="2">show ip protocols</font><font face="Arial"> and see what we get.</font></p>
<p><font face="Terminal" size="2">eRouter4#show ip protocols<br>
Routing Protocol is "rip"<br>
Sending updates every 30 seconds, next due in 12 seconds<br>
Invalid after 180 seconds, hold down 180, flushed after 240<br>
Outgoing update filter list for all interfaces is<br>
Incoming update filter list for all interfaces is<br>
Redistributing: rip<br>
Default version control: send version 1, receive any version<br>
Interface Send Recv Key-chain<br>
Ethernet0 1 1 2<br>
Serial0 1 1 2<br>
Routing for Networks:<br>
172.16.0.0<br>
Routing Information Sources:<br>
Gateway Distance Last Update<br>
172.16.10.2 120 00:00:09<br>
Distance: (default is 120)<br>
<br>
eRouter4#</font></p>
<p><font face="Arial">Looking at the output in detail we see we are sending updates every 30
seconds. We know RIP is a distance vector routing protocol so it exchanges
its entire routing table every 30 seconds. We also see our network
statements are working by noticing the networks are both under the Routing for
Networks area. The last area to notice is the Distance which we said was
administrative distance. This tells us the default is 120 and that is what
we are using. </font> </p>
<p> </p>
<p><font face="Arial" size="2"><span class="724482219-24092001">Copyright (c)
1998-2003 Boson Software, Inc. All Rights Reserved.</span></font></p>
</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 + -