EIGRP 小記

1. Classless
2.支援VLSM
3.Unequal-Cost pathways  (OSPF Equal-Cost Load Balancing)
4.預設會Auto Summary
..........


EIGRP有三張Table
1.neighbor Table
         |
         |     dual 演算法
         V
2.Topology Table (不是Database),已經知道下一站要怎麼走,OSPF還要使用SPF演算法
a.路徑走Successor,若Successor斷掉,則走Feasible Successor
b.FD值=介面到下一站Router的Metric+AD值
c.要成為Feasible Successor,必須AD值小於Successor的FD值(Metric)


3.Riouting Table




EIGRP 也有送Hello Packets(預設每5秒送一次Hello)，會包含AS Number，若是AS Number不同，鄰居關係會無法建立
OSPF 中的Process ID可以不用,但是Area要相同


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例如
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B3#show ip interface brief 
Interface              IP-Address      OK? Method Status                Protocol

FastEthernet0/0        172.16.4.254    YES manual up                    up

FastEthernet0/1        unassigned      YES unset  administratively down down

Serial0/0/0            192.168.1.21    YES manual up                    up

Serial0/0/1            192.168.1.6     YES manual up                    up

Vlan1                  unassigned      YES unset  administratively down down
B3#



B3(config)#router eigrp 100  (AS Number為100)

B3(config-router)#network 172.16.4.254 0.0.0.0  (不打Wildcard Mask也可以 or 172.16.0.0)
B3(config-router)#network 192.168.1.21 0.0.0.0
B3(config-router)#network 192.168.1.6 0.0.0.0
B3(config-router)#no auto-summary (取消Auto Summary)





B3#show ip protocols 


Routing Protocol is "eigrp  100 " 
  Outgoing update filter list for all interfaces is not set 
  Incoming update filter list for all interfaces is not set 
  Default networks flagged in outgoing updates  
  Default networks accepted from incoming updates 
  EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
  EIGRP maximum hopcount 100
  EIGRP maximum metric variance 1
Redistributing: eigrp 100
  Automatic network summarization is in effect  
  Automatic address summarization: 
    192.168.1.0/24 for FastEthernet0/0
      Summarizing with metric 2169856
    172.16.0.0/16 for Serial0/0/0, Serial0/0/1
      Summarizing with metric 28160
  Maximum path: 4
  Routing for Networks:  
     172.16.4.254/32
     192.168.1.21/32
     192.168.1.6/32
  Routing Information Sources:  
    Gateway         Distance      Last Update 
  Distance: internal 90 external 170




檢查有無錯誤
show iop route
show ip protocols



B3#show ip eigrp topology 
IP-EIGRP Topology Table for AS 168


Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
       r - Reply status


P 172.16.4.0/24, 1 successors, FD is 28160
         via Connected, FastEthernet0/0
P 192.168.1.20/30, 1 successors, FD is 2169856
         via Connected, Serial0/0/0
P 192.168.1.4/30, 1 successors, FD is 2169856
         via Connected, Serial0/0/1
P 172.16.3.0/24, 1 successors, FD is 2172416
         via 192.168.1.5 (2172416/28160), Serial0/0/1
P 192.168.1.16/30, 1 successors, FD is 2681856
         via 192.168.1.5 (2681856/2169856), Serial0/0/1






B3#show ip eigrp neighbors 
IP-EIGRP neighbors for process 168
H   Address         Interface      Hold Uptime    SRTT   RTO   Q   Seq
                                   (sec)          (ms)        Cnt  Num
0   192.168.1.5     Se0/0/1        13   00:04:10  40     1000  0   10






B3#show ip eigrp interfaces 
IP-EIGRP interfaces for process 168


                        Xmit Queue   Mean   Pacing Time   Multicast    Pending
Interface        Peers  Un/Reliable  SRTT   Un/Reliable   Flow Timer   Routes
Fa0/0              0        0/0      1236       0/10           0           0
Se0/0/0            0        0/0      1236       0/10           0           0
Se0/0/1            1        0/0      1236       0/10           0           0



Peers 代表鄰居關係數

啟用驗證
key chain abc
key1
key-string kfc
interface fa 0/1

在介面套上
ip authentication mode eigrp 100 md5
ip authentication key-chain eigrp 100 abc



Routing Protocol的比較可以參考這裡