關於有類路由協議和無類路由協議
有類路由協議:
RIPv1,IGRP
無類路由協議:RIPv2,EIGRP,OSPF,IS-IS,BGP
有類路由協議在主類邊界路由器上自動匯總:(拋開接口談網絡都是扯淡)
(1) 對於相同主類網絡的子網,如果mask與出口mask相同,則把該子網通過外出接口發布出去;
(2) 對於相同主類網絡的子網,如果mask與出口接口的mask不同,則把該子網丟棄;對於不同主類網絡的子網,無論mask與出口接口的mask是否相同,把該網段匯總成主類網絡發布出去。
(3)對於不同主類網絡的子網,無論mask與出口接口的mask是否相同,把該網段匯總成主類網絡發布出去。
R1配置:
interface Loopback0
ip address 10.0.1.1 255.255.255.0
interface Loopback1
ip address 10.0.2.1 255.255.255.128
interface Loopback2
ip address 11.0.0.1 255.255.255.0
interface Loopback3
ip address 11.0.1.1 255.255.255.128
interface Serial1/0
ip address 10.0.0.1 255.255.255.0
R2配置:
interface Serial1/0
ip address 10.0.0.2 255.255.255.0
interface Serial1/1
ip address 172.16.0.2 255.255.255.0
R3配置:
interface Serial1/1
ip address 172.16.0.1 255.255.255.0
對R1和R2路由器配置RIPv1路由協議:
R1:
router rip
network 10.0.0.0
network 11.0.0.0
R2:
router rip
network 10.0.0.0
查看R2的路由表:
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.0.0 is directly connected, Serial1/1
10.0.0.0/24 is subnetted, 2 subnets
C 10.0.0.0 is directly connected, Serial1/0
R 10.0.1.0 [120/1] via 10.0.0.1, 00:00:02, Serial1/0 //與發布路由的出接口掩碼相同,則發布出去
R 11.0.0.0/8 [120/1] via 10.0.0.1, 00:00:02, Serial1/0 //與接口處於不同子網,則按照主網絡發布出去
解析:
(1)R 10.0.1.0 [120/1] via 10.0.0.1, 00:00:02, Serial1/0
Loopback0的IP地址設置掩碼為24位,與出口接口s1/0的掩碼一致,因此按照上文中的第一種情況,該子網可以發布出去;
Loopback1的IP地址設置掩碼為25位,與出口接口s1/0的掩碼不一致,因此按照上文中的第二種情況,該子網被拋棄:
R2#ping 10.0.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/84/340 ms
R2#ping 10.0.2.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.2.1, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
(2)R 11.0.0.0/8 [120/1] via 10.0.0.1, 00:00:02, Serial1/0
Loopback2和Loopback3的IP地址與出口接口s1/0屬於不同的主類網絡,因此按照上文中的第三種情況,將該網段匯總成主類網絡發布出去。
對R3路由器配置RIPv1路由協議:
router rip
network 172.16.0.0
在R2路由器上發布172.16.0.0網段
router rip
network 172.16.0.0
查看R3路由表:
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.0.0 is directly connected, Serial1/1
R 10.0.0.0/8 [120/1] via 172.16.0.2, 00:00:28, Serial1/1
R 11.0.0.0/8 [120/2] via 172.16.0.2, 00:00:28, Serial1/1
解析:
R 10.0.0.0/8 [120/1] via 172.16.0.2, 00:00:28, Serial1/1
R2上的路由表信息:
C 10.0.0.0 is directly connected, Serial1/0
R 10.0.1.0 [120/1] via 10.0.0.1, 00:00:02, Serial1/0
需要通過R2路由器的s1/1接口發布出去,因為與s1/1接口不屬於同一主類網絡,因此匯總為10.0.0.0/8發布出去。
R3路由器ping R1路由器的結果如下所示:
R3#ping 10.0.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.1.1, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 44/418/1540 ms
R3#ping 10.0.2.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.2.1, timeout is 2 seconds:
UUUUU
Success rate is 0 percent (0/5)
R3#ping 11.0.0.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 11.0.0.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 44/48/64 ms
R3#ping 11.0.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 11.0.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 44/51/80 ms
只有對loopback1接口顯示UUUUU,意思為主機不可達
有類和無類協議的區別就在於是否支持VLSM,有類的不發送掩碼,不支持VLSM,無類的相反。默認情況下有類和無類在邊界路由器上自動進行匯總(OSPF不在邊界自動匯總),無類協議可以關閉自動匯總,no auto-summary。
假如在R3路由器上配置loopback0接口,地址配置為10.0.3.1/24,路由協議采用RIPv2,如果按照默認匯總默認路由,R2路由表會出現10.0.0.0/8不知道出口的情況。
關於有類路由協議和無類路由協議