ISIS与OSPF域间选路比较 Document ID: 00012

目录 提要 正文 TOPO如下 基本配置如下 验证 附注

提要：ISIS与OSPF域间选路比较（ISIS部分） TOPO如下： 基本配置如下： l R1 l R2 l R3 l R4 l R5 R1基本配置 interface Loopback0 ip address 1.1.1.1 255.255.255.0 ! interface Serial1/0 ip address 12.1.1.1 255.255.255.0 ip router isis ! interface Serial2/0 ip address 13.1.1.1 255.255.255.0 ip router isis ! router isis net 02.0010.0100.1001.00 passive-interface Loopback0 R2基本配置 interface Loopback0 ip address 2.2.2.2 255.255.255.0 ! interface Serial1/0 ip address 24.1.1.2 255.255.255.0 ip router isis ! interface Serial2/0 ip address 12.1.1.2 255.255.255.0 ip router isis ! router isis net 01.0020.0200.2002.00 passive-interface Loopback0 R3基本配置 interface Loopback0 ip address 3.3.3.3 255.255.255.0 ! interface Ethernet0/0 ip address 34.1.1.3 255.255.255.0 ip router isis ! interface Serial1/0 ip address 13.1.1.3 255.255.255.0 ip router isis ! interface Serial2/0 ip address 35.1.1.3 255.255.255.0 ip router isis ! router isis net 03.0030.0300.3003.00 passive-interface Loopback0 R4基本配置 interface Loopback0 ip address 4.4.4.4 255.255.255.0 ! interface Ethernet0/0 ip address 34.1.1.4 255.255.255.0 ip router isis ! interface Serial2/0 ip address 24.1.1.4 255.255.255.0 ip router isis ! router isis net 03.0040.0400.4004.00 passive-interface Loopback0 ! R5基本配置 interface Loopback0 ip address 5.5.5.5 255.255.255.0 ! interface Serial1/0 ip address 35.1.1.5 255.255.255.0 ip router isis ! router isis net 03.0050.0500.5005.00 is-type level-1 passive-interface Loopback0 测试⑴： 在R3上查看2.0.0.0/24的路由，有两条路径做负载 r3#sho ip route | be 2.0.0.0/24 2.0.0.0/24 is subnetted, 1 subnets i L2 2.2.2.0 [115/20] via 13.1.1.1, Serial1/0 [115/20] via 34.1.1.4, Ethernet0/0 r3#traceroute 2.2.2.2 Type escape sequence to abort. Tracing the route to 2.2.2.2 1 * 13.1.1.1 32 msec ――>走下面的那条 34.1.1.4 4 msec ――>走上面的那条 2 12.1.1.2 56 msec 24.1.1.2 20 msec * 在R5上使用扩张ping 加record参数 r5#ping Protocol [ip]: Target IP address: 2.2.2.2 Repeat count [5]: Datagram size [100]: Timeout in seconds [2]: Extended commands [n]: y Source address or interface: Type of service [0]: Set DF bit in IP header? [no]: Validate reply data? [no]: Data pattern [0xABCD]: Loose, Strict, Record, Timestamp, Verbose[none]: re Number of hops [ 9 ]: Loose, Strict, Record, Timestamp, Verbose[RV]: Sweep range of sizes [n]: Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds: Packet has IP options: Total option bytes= 39, padded length=40 Record route: <*> (0.0.0.0) (0.0.0.0) (0.0.0.0) (0.0.0.0) (0.0.0.0) (0.0.0.0) (0.0.0.0) (0.0.0.0) (0.0.0.0) Reply to request 0 (48 ms). Received packet has options Total option bytes= 40, padded length=40 Record route: (35.1.1.5) (34.1.1.3) (24.1.1.4) ――>走上面的那条 (2.2.2.2) (24.1.1.2) (34.1.1.4) (35.1.1.3) (35.1.1.5) <*> (0.0.0.0) End of list Reply to request 1 (72 ms). Received packet has options Total option bytes= 40, padded length=40 Record route: (35.1.1.5) (13.1.1.3) (12.1.1.1) ――>走下面的那条 (2.2.2.2) (12.1.1.2) (13.1.1.1) (35.1.1.3) (35.1.1.5) <*> (0.0.0.0) End of list Reply to request 2 (48 ms). Received packet has options Total option bytes= 40, padded length=40 Record route: (35.1.1.5) (34.1.1.3) (24.1.1.4) ――>走上面的那条 (2.2.2.2) (24.1.1.2) (34.1.1.4) (35.1.1.3) (35.1.1.5) <*> (0.0.0.0) End of list Reply to request 3 (72 ms). Received packet has options Total option bytes= 40, padded length=40 Record route: (35.1.1.5) (13.1.1.3) (12.1.1.1) ――>走下面的那条 (2.2.2.2) (12.1.1.2) (13.1.1.1) (35.1.1.3) (35.1.1.5) <*> (0.0.0.0) End of list Reply to request 4 (48 ms). Received packet has options Total option bytes= 40, padded length=40 Record route: (35.1.1.5) (34.1.1.3) (24.1.1.4) ――>走上面的那条 (2.2.2.2) (24.1.1.2) (34.1.1.4) (35.1.1.3) (35.1.1.5) <*> (0.0.0.0) End of list 测试⑵ 注意如果使用traceroute跟踪2.2.2.2 的路径时，如果没有在R3上面关闭fast－switching是看不出有两条的。 r5#traceroute 2.2.2.2 没有在R3关闭fast－switching的效果 Type escape sequence to abort. Tracing the route to 2.2.2.2 1 35.1.1.3 28 msec 20 msec 20 msec 2 13.1.1.1 40 msec 40 msec 40 msec 3 12.1.1.2 52 msec * 48 msec 为了达到实验效果我们关闭R3所有接口的fast－switching，然后在R5上traceroute 2.2.2.2 r3(config)#int s1/0 r3(config-if)#no ip route-cac r3(config-if)#no ip route-cache r3(config-if)#int e0/0 r3(config-if)#no ip route-cache r3(config-if)#int s2/0 r3(config-if)#no ip route-cache r5#traceroute 2.2.2.2 Type escape sequence to abort. Tracing the route to 2.2.2.2 1 35.1.1.3 16 msec 20 msec 20 msec 2 13.1.1.1 40 msec ――>走下面的那条 34.1.1.4 20 msec ――>走上面的那条 13.1.1.1 40 msec 3 24.1.1.2 52 msec 12.1.1.2 48 msec * 总结： IS-IS选路基本过程： １、到外部区域：Ｌ１先选到最近的Ｌ１／Ｌ２ ２、L1/L2路由器根据L2拓扑数据库选路

偶路过               ............:loveliness: