20201118 cisco EIGRP (二)

課堂資料

Enhanced Interior Gateway Routing Protocol ( EIGRP ) 增強型內部網關路由協定:

ACL 封包過濾表:

EIGRP Metric Caculation

Metric = bandwidth ( slowest link ) - delay ( sum of delays ) - Delay ( in tens of microseconds , multiplied by 256 ) - Bandwidth = [ ( 10^7 / minimum bandwidth link along the path in kbps ) ] * 256
Metric = k1 * BW + [ ( k2 * BW / ( 256 - load ) ) + k3 * delay ]
  • k1 = 1
  • k2 = 0
  • k3 = 1
  • k4 = k5 = 0

路徑
A --> B --> C --> D
least bw:64 kbps
total delay 6000 μs
( 10^7 / 64 + 6000 / 10 ) * 256
A --> X --> Y --> Z --> D
least bw:256 kbps
total delay 8000 μs
( 10^7 / 64 + 8000 / 10 ) * 256
不等價 負載均衡
Network
Neighbor
FD
AD
172.16.0.0
B
30
10
C
20
10
D
45
25
  • Successor
  • Feasible Successor:ADCFD
C
D
via
FD
AD
B
3
1
D
4
2
E
4
3
via
FD
AD
B
2
1
C
5
3

ACL

Cisco 路由器 ACL 種類
Cisco 路由器的存取控制清單有三種:
(1) 『標準存取控制清單』( Standard ACL):僅檢視 IP 封包中的來源位址(source address) ,來決定封包是否允許通過,編號由 1~99, 1300~1999。
(2) 『延伸式存取清單』(Extended ACL):可比對 IP 封包中的 IP 標頭與上一層(TCP、UDP、、)標頭內的多個欄位,屬於比較進階細膩的過濾條件。編號由 100 ~ 199、2000 ~ 2699。
(3) 『名稱式存取清單』(Named ACL):是屬於前面兩種存取清單,但僅以名稱命名,也許這樣比較能了解該清單目的與功能。

課堂練習

Metric

R1
R2
R3
int e0/0
ip add 192.168.12.1 255.255.255.0
no shut
router eigrp 1
network 192.168.12.0
no auto-summary
do sh ip eigrp topology
router eigrp 1
metric weights 0 5 2 1 10 1
int e0/0
ip add 192.168.12.2 255.255.255.0
no shut
int e0/1
ip add 192.168.23.2 255.255.255.0
no shut
router eigrp 1
network 192.168.13.0
network 192.168.23.0
no auto-summary
do sh ip eigrp topology
do sh int e0/0 | include BW
int e0/0
ip add 192.168.23.3 255.255.255.0
no shut
router eigrp 1
network 192.168.23.0
no auto-summary
int lo 0
ip add 192.168.34.3 255.255.255.0
no shut
do sh ip eigrp 1 topology
do sh int l0 | include BW

Summarization

R1
R2
R3
R4
int e0/0
ip addr 172.16.13.1 255.255.255.0
no shut
router eigrp 1
network 172.16.13.0 0.0.0.255
no auto-summary
do ping 172.16.34.4
int e0/0
ip addr 172.16.23.2 255.255.255.0
no shut
router eigrp 1
network 172.16.23.0 0.0.0.255
no auto-summary
int e0/0
ip addr 172.16.13.3 255.255.255.0
no shut
int e0/1
ip addr 172.16.23.3 255.255.255.0
no shut
int e0/2
ip addr 172.16.34.3 255.255.255.0
no shut
router eigrp 1
network 172.16.13.0 0.0.0.255
network 172.16.23.0 0.0.0.255
network 172.16.34.0
no auto-summary
do sh ip ro | begin Gateway
int e0/2
ip summary-address eigrp 1 172.16.0.0 255.255.224.0
do sh ip ro | begin Gateway
no ip summary-address eigrp 1 172.16.0.0 255.255.224.0
router eigrp 1
auto-summary
do sh ip ro | begin Gateway
router eigrp 1
summary-metric 172.16.0.0 255.255.224.0 100 100 1 1 1 distance 50
int e0/0
ip addr 172.16.34.4 255.255.255.0
no shut
router eigrp 1
network 172.16.34.0
no auto-summary
do sh ip ro
do sh ip ro | begin Gateway
do sh ip ro | begin Gateway

ACL ( Access Control )

R1
R2
int e0/0
ip add 12.1.1.1 255.255.255.0
no shut
int lo 0
ip add 1.1.1.1 255.255.255.0
no shut
do sh ip int brief
do ping 12.1.1.2 source 1.1.1.1
do ping 12.1.1.2 source 12.1.1.1
int e0/0
ip add 12.1.1.2 255.255.255.0
no shut
exit
ip route 1.1.1.0 255.255.255.0 12.1.1.2
access-list 1 deny host 1.1.1.1
access-list 1 permit any
int e0/0
ip access-group 1 in
exit
no access-list 1
int e0/0
no ip access-group 1 in

實戰練習