Using Route Maps to Manipulate Basic BGP Paths参考.ppt

Using Route Maps to Manipulate Basic BGP Paths BGP Is Designed to Implement Policy Routing BGP Local Preference Setting a Default Local Preference BGP Multi-Exit Discriminator: Inbound Metric BGP Using the Default MED BGP Using Route Maps and the MED LAB 1 : BGP本地优先 LAB 2 : BGP本地优先 LAB 3 : BGP MED实验 LAB 4 : BGP MED实验 LAB 5 : BGP Weight LAB 6 : BGP Weight LAB 7 : BGP路径欺骗 LAB 8 : BGP路由标记 END Configuring Route Summarization with BGP CIDR and Aggregate Addresses 在BGP中路由可以在任意的一个自治系统或是路由器上被汇总. BGP4是一个无类的路由协议.支持VLSM和最长匹配路由. Network Boundary Summarization BGP, RIPv1, RIPv2, IGRP,和EIGRP会在主类网络边界执行自动的路由汇总. BGP, RIPv2和EIGRP可以手工的关闭自动汇总特性. IANA的CIDR强制从A类地址开始进行汇总. BGP network Command BGP Summarization Using the network Command and Static Route to Null 0 Configuring BGP for Aggregate Addressing BGP Summarization Using the aggregate-address Command BGP Aggregation LAB 1 : BGP路由汇总 LAB 2 : BGP路由汇总 END Cisco Network Academy. All rights reserved. CCNP+ BSCI v3.0 Cisco Network Academy. All rights reserved.. CCNP+ BSCI v3.0 BGP is designed for manipulating routing pathways. bgp default local-preference value Router(config-router)# 决定离开本自治系统最佳的路径 默认值为100; 较高的值会被优先选择 更改默认的本地优先级的值 所有路由都运行了BGP协议. 路由器B宣告本地优先级为500给本自治系统的其它路由器． 路由器A宣告本地优先级为200给本自治系统的其它路由器. BGP会选择较高的优先级的路径，因此所有的流量会通过B路由器离开本自治系统到达其它的自治系统． 当两个自治系统相互有多条路径时通常会使用MED决定具体使用那一条路径. MED值越低越会被优先选择. 默认的MED值为0. MED是不可以被传递的. 设置默认的MED值. 路由器通告给所有的EBGP路由器时MED将修改成指定的值. default-metric number Router(config-router)# AS 65001的路由器B自治系统宣告MED为99. AS 65001的路由器A自治系统宣告MED为1001. 如果AS 65004没有配置其它策略的情况下, 将会选择从路由器Y到达AS 650001的自治系统.因为优先选择MED较低的路径. R3 10.1.1.1/24S1/1 10.1.3.2/24S1/0 S1/010.1.1.2/24 10.1.2.1/24S1/1 10.1.2.2/24S1/0 S1/110.1.3.1/24 R1 FA0/010.1.5.2/24 FA0/010.1.5.1/24 R4 AS 64512 AS 64513 150.150.1.1/24 R2 router bgp 64513 bgp default local- preference 200 router bgp