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：

EIGRP 增強型內部網關路由協定 - Jan Ho 的網絡世界Jan Ho 的網絡世界

ACL 封包過濾表：

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

via	FD	AD
B	3	1
D	4	2
E	4	3

D

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

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

R2

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

R3

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

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

R2

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

R3

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

R4

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

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

R2

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