FAQ-如何利用BGP扩展属性使不同VPN之间的特定网段互通

发布时间:  2011-04-22 浏览次数:  76 下载次数:  5
问题描述
Q:
I国M客户NGN承载网,所有业务使用VPN进行隔离。现客户新建IPCC网络,要求新建IPCC网络的部分网段与原网络的Callcenter部分实现互通。如何实现?
处理过程
根因
N/A
解决方案

A: 
可以使用BGP扩展属性来实现以上需求。共三步:
   1、配置ip-prefix过滤特定网络;
    ip ip-prefix vpnb index 10 permit 4.4.4.4 32     //network range of vpnb                          
    ip ip-prefix vpna3 index 10 permit 3.3.3.3 32    //network range of vpna
    #
   
   2、配置路由策略,在匹配第1步ip-prefix,应用扩展属性增加需要访问的VPN的rt值,注意additive; 
     route-policy vpnb-policy permit node 10                                         
       if-match ip-prefix vpnb                                                        
       apply extcommunity rt 65535:3001 additive                                     
     #                                                                               
     route-policy vpna3-policy permit node 10                                        
       if-match ip-prefix vpna3                                                       
       apply extcommunity rt 65535:111  additive                                      
     # 
    
   3、在VPN实例下应用路由策略。
    ip vpn-instance vpna                                                            
      route-distinguisher 100:1                                                      
      export route-policy vpna3-policy                                               
      vpn-target 65535:3001 export-extcommunity                                      
      vpn-target 65535:3001 import-extcommunity                                      
    ip vpn-instance vpnb                                                            
      route-distinguisher 100:2                                                      
      export route-policy vpnb-policy                                                
      vpn-target 65535:111 export-extcommunity                                       
      vpn-target 65535:111 import-extcommunity                                       
    #     
4、测试结果达到客户要求,具体见附件。

建议与总结
BGP扩展属性与路由策略的使用是非常灵活的,可以实现很多功能。

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