奇偶ACL的網絡號匹配 2007-03-27 18:21:01
實驗要求:使用ACL,route-map配合重發布,R1僅能夠學習到奇數位的網絡號或是偶數位的網絡號,即192.168.x.0的x爲奇或爲偶.
實驗步驟一:配置各路由器的IP,並且確認直接接口可以PING通.
實驗步驟二:配置RIP和OSPF的協議,同時network正確的網絡接口,並且注意passive-interface的使用
實驗步驟三:在R2上配置重發布,確認網絡是可以通過重發布學習到所有的網絡.
題目要求分析:
R1僅能夠學習到R3的奇數位的網絡號或是偶數號的網絡號.將各個子網拆成二進制觀察規律
192.168.1.0/24 | 192.168.0000 0001.0/24 |
192.168.2.0/24 | 192.168.0000 0010.0/24 |
192.168.3.0/24 | 192.168.0000 0011.0/24 |
192.168.4.0/24 | 192.168.0000 0100.0/24 |
192.168.5.0/24 | 192.168.0000 0101.0/24 |
192.168.6.0/24 | 192.168.0000 0110.0/24 |
192.168.7.0/24 | 192.168.0000 0111.0/24 |
192.168.8.0/24 | 192.168.0000 1000.0/24 |
用於偶數位的網絡號:access-list 1 permit 192.168.0.0 0.0.254.0
192.168.0000 0000.0
000.000.1111 1110.0
用於奇數位的網絡號:access-list 2 permit 192.168.1.0 0.0.254.0
192.168.0000 0001.0
000.000.1111 1110.0
實驗實踐一:在R2上配置,測試偶數位的匹配:
access-list 1 permit 192.168.0.0 0.0.254.0
!
route-map parity-acl permit 10
match ip address 1
!
router ospf 1
redistribute rip subnets route-map parity-acl
在R1上查看路由表,發現只有偶數位的網絡號:
O E2 192.168.8.0/24 [110/20] via 172.16.1.2, 00:00:38, Serial1/1
O E2 192.168.4.0/24 [110/20] via 172.16.1.2, 00:00:38, Serial1/1
O E2 192.168.6.0/24 [110/20] via 172.16.1.2, 00:00:38, Serial1/1
O E2 192.168.2.0/24 [110/20] via 172.16.1.2, 00:00:38, Serial1/1
實驗實踐二:no掉剛纔配置的acl和route-map,在R2上配置,測試奇數位的匹配
access-list 2 permit 192.168.1.0 0.0.254.0
!
route-map parity-acl permit 10
match ip address 2
!
router ospf 1
redistribute rip subnets route-map parity-acl
在R1上查看路由表,發現只有奇數位的網絡號:
O E2 192.168.5.0/24 [110/20] via 172.16.1.2, 00:00:27, Serial1/1
O E2 192.168.7.0/24 [110/20] via 172.16.1.2, 00:00:27, Serial1/1
O E2 192.168.1.0/24 [110/20] via 172.16.1.2, 00:00:27, Serial1/1
O E2 192.168.3.0/24 [110/20] via 172.16.1.2, 00:00:27, Serial1/1