BGP基于前缀的ORF示例

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组网需求

  1. 如图PE1与PE2分别属于AS 100和AS 200
  2. 要求PE2 的出口路由只发送符合PE1 入口策略的路由

组网拓扑

BGP基于前缀的ORF

配置思路

  1. 在PE1上配置基于前缀的ORF功能

配置命令

  1. 配置路由器基本功能以及各接口IP地址

    • PE 1配置

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      sys PE 1	
      int g0/0/0
        ip add 111.1.1.1 30
      int LoopBack 0
        ip add 1.1.1.1 32

  • PE 2配置

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    sys
    sys PE 2
    int g0/0/0
      ip add 111.1.1.2 30
    int LoopBack 0
      ip ad d 2.2.2. 32

  1. 配置EBGP连接

    • PE 1

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      sys
      bgp 10
        router-id 1.1.1.1
        peer 111.1.1.2 as-number 20

  • PE 2配置

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    sys
    bgp 20
      router-id 2.2.2.2
      peer 111.1.1.1 as-numebr 10

  1. 宣告路由

    • PE 2配置

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      sys
      ip route-static 3.3.3.3 32 NULL0
      ip route-static 4.4.4.4 32 NULL0
      ip route-static 5.5.5.5 32 NULL0

      bgp 20
        import-route static

  1. 配置IP前缀过滤

    • PE 1配置前缀过滤

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      sys
      ip ip-prefix BGP_ORF_List permit 4.4.4.0 24 greater-equal 32
          
          bgp 10
          peer 111.1.1.2 ip-prefix BGP_ORF_List import

  1. 配置BGP ORF

    • PE 1配置

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      bgp 10
          peer 111.1.1.2 capability-advertise orf ip-prefix both

  • PE 2配置

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    bgo 20
        peer 111.1.1.1 capability-advertise orf ip-prefix both

查看结果

  1. 没有配置ORF之前的路由表

    • PE 2上宣告的路由

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      dispaly bgp routing peer 111.1.1.1 advertised-routers

      <PE2>display bgp routing peer 111.1.1.1 advertised-routes

       BGP Local router ID is 2.2.2.2 
       Status codes: * - valid, > - best, d - damped,
                     h - history,  i - internal, s - suppressed, S - Stale
                     Origin : i - IGP, e - EGP, ? - incomplete


       Total Number of Routes: 3
            Network            NextHop        MED        LocPrf    PrefVal Path/Ogn

       *>   3.3.3.3/32         111.1.1.2       0                     0      20?
       *>   4.4.4.4/32         111.1.1.2       0                     0      20?
       *>   5.5.5.5/32         111.1.1.2       0                     0      20?

  • PE1 上接收到路由

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    display bgp routing-table peer 111.1.1.2 received-routers

    <PE1>display bgp routing-table peer 111.1.1.2 received-routes

     BGP Local router ID is 1.1.1.1 
     Status codes: * - valid, > - best, d - damped,
                   h - history,  i - internal, s - suppressed, S - Stale
                   Origin : i - IGP, e - EGP, ? - incomplete


     Total Number of Routes: 1
          Network            NextHop        MED        LocPrf    PrefVal Path/Ogn

     *>   4.4.4.4/32         111.1.1.2       0                     0

  1. 配置ORF之后的路由表

    • PE 2上宣告的路由

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      display bgp routing peer 111.1.1.1 advertised-routers

      <PE2>dis bgp routing-table peer 111.1.1.1 advertised-routes 

       BGP Local router ID is 2.2.2.2 
       Status codes: * - valid, > - best, d - damped,
                     h - history,  i - internal, s - suppressed, S - Stale
                     Origin : i - IGP, e - EGP, ? - incomplete


       Total Number of Routes: 1
            Network            NextHop        MED        LocPrf    PrefVal Path/Ogn

       *>   4.4.4.4/32         111.1.1.2       0                     0      20?

  • PE1 上接收到路由

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    dispaly bgp routing-table peer 111.1.1.2 received-routers

    <PE1>dis bgp routing-table peer 111.1.1.2 received-routes 

     BGP Local router ID is 1.1.1.1 
     Status codes: * - valid, > - best, d - damped,
                   h - history,  i - internal, s - suppressed, S - Stale
                   Origin : i - IGP, e - EGP, ? - incomplete


     Total Number of Routes: 1
          Network            NextHop        MED        LocPrf    PrefVal Path/Ogn

     *>   4.4.4.4/32         111.1.1.2       0                     0      20?

  1. PE1 上查看邻居信息

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    display bgp peer verbose

    <PE1>dis bgp peer 111.1.1.2 verbose 

    	BGP Peer is 111.1.1.2,  remote AS 20  
    	Type: EBGP link
    	BGP version 4, Remote router ID 2.2.2.2
    	Update-group ID: 0  
    	BGP current state: Established, Up for 00h03m48s 
    	BGP current event: RecvKeepalive
    	BGP last state: OpenConfirm
    	BGP Peer Up count: 3
    	Received total routes: 1
    	Received active routes total: 1
    	Advertised total routes: 0
    	Port:  Local - 179	Remote - 50000
    	Configured: Connect-retry Time: 32 sec
    	Configured: Active Hold Time: 180 sec	Keepalive Time:60 sec
    	Received  : Active Hold Time: 180 sec
    	Negotiated: Active Hold Time: 180 sec	Keepalive Time:60 sec
    	Peer optional capabilities:
    	Peer supports bgp multi-protocol extension
    	Peer supports bgp route refresh capability
    	Peer supports bgp outbound route filter capability
     	
            // 基于前缀的BGP ORF协商信息
            Support Address-Prefix: IPv4-UNC address-family, rfc-compatible, both
    	Peer supports bgp 4-byte-as capability
    	Address family IPv4 Unicast: advertised and received
     Received: Total 7 messages
    		 Update messages 		1 
    		 Open messages 			1 
    		 KeepAlive messages 		4 
    		 Notification messages  	0 
    		 Refresh messages 		1
     Sent: Total 7 messages
    		 Update messages 		0 
    		 Open messages 			2 
    		 KeepAlive messages 		4 
    		 Notification messages  	0 
    		 Refresh messages 		1
     Authentication type configured: None
     Last keepalive received: 2022/03/28 21:54:05 UTC-08:00    
     Last keepalive sent    : 2022/03/28 21:54:04 UTC-08:00    
     Last update    received: 2022/03/28 21:51:05 UTC-08:00    
     Minimum route advertisement interval is 30 seconds
     Optional capabilities:
     Route refresh capability has been enabled
     Outbound route filter capability has been enabled
         
         // 基于前缀的BGP ORF协商信息
         Enable Address-Prefix: IPv4-UNC address-family, rfc-compatible, both
     4-byte-as capability has been enabled
     Peer Preferred Value: 0
     Routing policy configured:
     No import update filter list
     No export update filter list
     Import prefix list is: BGP_ORF_List
     No export prefix list
     No import route policy 
     No export route policy
     No import distribute policy 
     No export distribute policy
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