eigrptheory.htm

BOSON NETSIM是目前最好的路由器模拟软件

eRouter2(config-if)#ip address 10.1.1.2 255.255.255.0<br>
eRouter2(config-if)#no shut<br>
eRouter2(config-if)#exit<br>
01:23:17: %LINK-3-UPDOWN: Interface Ethernet0, changed state to up<br>
01:23:18: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0, changed state to up<br>
eRouter2(config)#</font></p>

<p><font face="Arial">Now add the EIGRP stuff!</font></p>

<p><font face="Terminal" size="2">eRouter2(config)#router EIGRP 100<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 EIGRP running on our network between eRouter1 and eRouter2.&nbsp;
We need to get eRouter4 setup.</font></p>

<p><font face="Arial">We need to
connect to eRouter4 and follow the same instructions.&nbsp; Lets select eRouter4
from the button menu.&nbsp; When we connect we are going to set a hostname to
<b>eRouter4</b>, then set the IP addresses to the <a href="#ip">table above</a> and configure EIGRP.&nbsp;&nbsp;</font></p>

<p><font color="#FF0000" face="Arial"><br>
</font><font face="Terminal" size="2">eRouter>en<br>
eRouter#conf t<br>
Enter configuration commands, one per line.  End with CNTL/Z.<br>
eRouter(config)#hostname eRouter2<br>
eRouter4(config)#int s0<br>
eRouter4(config-if)#ip address 172.16.10.2 255.255.255.0<br>
eRouter4(config-if)#no shut<br>
eRouter4(config-if)#exit<br>
01:23:17: %LINK-3-UPDOWN: Interface Ethernet0, changed state to up<br>
01:23:18: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0, changed state to up<br>
eRouter4(config)#</font></p>

<p><font face="Arial">Now add the EIGRP stuff!</font></p>

<p><font face="Terminal" size="2">eRouter4(config)#router EIGRP 100<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">New show commands that are 
used with EIGRP.</font></b></p>

<p><font face="Arial">&nbsp; Now that we have EIGRP running on our entire network lets verify that it is receiving routes.&nbsp;
To do this we will be using some show commands.&nbsp; The most common one is 'show ip route'.&nbsp; This displays all entries in the routing table.&nbsp; If we do
this on our Router B we will see the route to our directly connected eRouter1.&nbsp;
Lets take a look at our routing table, to do this type: <font color="#FF0000">show
ip route </font>from the privilege mode.</font></p>

<p><font face="Arial">Lets look at the first entry &quot;</font><font face="Terminal" size="2">D&nbsp; 10.1.1.0/24 [90/1] 
via 172.16.10.2, 00:00:21, Serial0</font><font face="Arial">&quot;.&nbsp;
It starts off with D this says it is a EIGRP route, then it says the destination
network with a subnet mask, in this case it is 10.1.1.0 with a /24 (255.255.255.0)
subnet mask.&nbsp; Next it gives 90/1 the 90 is the administrative distance, EIGRP's default administrative distance is 
90.&nbsp; 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.&nbsp;
The 1 is the number of hops required to get to the destination network.&nbsp; The next
piece of information is the via 172.16.10.2 that is the next hop address it must go
to.&nbsp; The last item is that this information was learned via
Serial0.&nbsp;&nbsp;</font></p>

<p><font face="Arial">Another great command is </font>
<font face="Terminal" size="2">show ip protocols</font><font face="Arial">.&nbsp; This displays information
about the IP routing protocols you have enabled.&nbsp; 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 &quot;eigrp 10&quot;<br>
  Outgoing update filter list for all interfaces is<br>
  Incoming update filter list for all interfaces is<br>
  Default networks flagged in outgoing updates<br>
  Default networks accepted from incoming updates<br>
  EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0<br>
  EIGRP maximum hopcount 100<br>
  EIGRP maximum metric variance 1<br>
  Redistributing: eigrp 100<br>
  Routing for Networks:<br>
172.16.0.0<br>
  Routing Information Sources:<br>
    Gateway         Distance      Last Update<br>
172.16.10.2 100      00:00:09<br>
  Distance: internal 90 external 170<br>
<br>
eRouter4#</font></p>

<p><font face="Arial">Looking at the output in detail&nbsp; there is no given time period of sending 
updates.&nbsp; We know EIGRP is a hybrid distance vector routing protocol so it exchanges
its entire routing table when it first finds its neighbors but after that it 
only sends updates when changes are made.&nbsp; We also see our network
statements are working by noticing the networks are both under the Routing for
Networks area.&nbsp; The last area to notice is the Distance which we said was
administrative distance.&nbsp; This tells us the default for internal routes is 
90 and&nbsp; 170 for external routes.&nbsp; </font> </p>

<p><font face="Arial">There are a few other commands we should take a look at. The first is </font>
<font face="Terminal" size="2">show ip eigrp traffic</font><font face="Arial"> This command displays simple information about how much 
traffic EIGRP is sending on your network.&nbsp; Lets look at the output.</font></p>

<p><font face="Terminal" size="2">R4#show ip eigrp traffic<br>
IP-EIGRP Traffic Statistics for process 10<br>
Hellos sent/received: 985/974<br>
Updates sent/received: 5/4<br>
Queries sent/received: 0/0<br>
Replies sent/received: 0/0<br>
Acks sent/received: 2/2<br>
Input queue high water mark 1, 0 drops</font></p>

<p><font face="Arial">Another more useful command is </font> 
<font face="Terminal" size="2">show ip eigrp neighbors</font><font face="Arial">.&nbsp; This lists all 
the neighbors that your router is exchanging information with. </font> </p>

<p><font face="Terminal" size="2">R1#show ip eigrp nei<br>
IP-EIGRP neighbors for process 10<br>
H&nbsp;&nbsp; Address&nbsp;&nbsp;&nbsp; Interface Hold Uptime&nbsp;&nbsp; SRTT&nbsp;&nbsp;&nbsp; RTO&nbsp;&nbsp; Q Seq<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
(sec)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
(ms)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Cnt Num<br>
1&nbsp;&nbsp;&nbsp; 1.1.1.2&nbsp;&nbsp; 
Et0&nbsp;&nbsp;&nbsp; 12&nbsp;&nbsp; 00:13:24&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
0&nbsp;&nbsp;&nbsp; 3000&nbsp;&nbsp;&nbsp;&nbsp; 0&nbsp;&nbsp; 2<br>
0&nbsp;&nbsp;&nbsp; 2.2.2.2&nbsp;&nbsp; 
Se0&nbsp;&nbsp;&nbsp; 14&nbsp;&nbsp; 00:14:05&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 0&nbsp;&nbsp;&nbsp; 
4500&nbsp;&nbsp;&nbsp;&nbsp; 0&nbsp;&nbsp; 2<br>
R1#</font></p>

<p><font face="Arial">The command </font><font face="Terminal" size="2">show ip eigrp interfaces</font><b><font face="Arial"> </font> </b><font face="Arial">displays all the interfaces on the 
router that are running EIGRP.</font></p>

<p><font face="Terminal" size="2">R1#show ip eigrp interfaces<br>
IP-EIGRP interfaces for process 10<br>
<br>
Xmit Queue Mean Pacing Time Multicast Pending<br>
Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer Routes<br>
Et0 1 0/0 0 0/10 0 0<br>
Se0 1 0/0 0 0/15 0 0<br>
R1#</font></p>

<p><font face="Arial">The last new command for EIGRP is </font>
<font face="Terminal" size="2">show ip eigrp topology</font><font face="Arial">.&nbsp;&nbsp; This command will 
list all associated neighbors and what network they are connected to.</font></p>

<p><font face="Terminal" size="2">R1#show ip eigrp topology<br>
IP-EIGRP Topology Table for process 10<br>
<br>
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,<br>
r - Reply status<br>
<br>
P 1.0.0.0/8, 1 successors, FD is 281600<br>
via Summary (281600/0), Null0<br>
P 1.1.1.0/24, 1 successors, FD is 281600<br>
via Connected, Ethernet0<br>
P 2.0.0.0/8, 1 successors, FD is 2169856<br>
via Summary (2169856/0), Null0<br>
P 2.2.2.0/24, 1 successors, FD is 2169856<br>
via Connected, Serial0<br>
R1#</font></p>

<p>&nbsp;</p>

<p><font face="Arial" size="2"><span class="724482219-24092001">Copyright (c) 
1998-2003 Boson Software, Inc.&nbsp; All Rights Reserved.</span></font></p>

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