一、组网及功能要求

image.png

  1. 某一虚网下，CPE可同时上连到不同POP点VPE。
  2. 双向连到VPE的CPE，上行流量支持ECMP或主备路径两种选路方式。

    二、实现原理

    借助BGP选路策略及多路径通告功能实现ECMP或主备路径。路由优先级通过路由MED值来干预，MED值越小，优先级越高。 CPE双上连VPE调研 - 图2

    三、验证过程

    验证设备选择CPE14、VPE14及VPE5三台设备，设备BGP基本信息如下
设备 bgp邻居地址 AS号
CPE14 192.168.0.105 1414
VPE14 192.168.0.106 1515
VPE5 192.168.0.2 444
  1. BGP邻居正常建立 ```css //CPE14邻居信息 [CPE14]display bgp peer ipv4 vpn-instance connection-nzy BGP local router ID: 14.14.14.14 Local AS number: 1414 Total number of peers: 2 Peers in established state: 2
      • Dynamically created peer Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State 192.168.0.2 444 1486 1730 0 3 22:02:35 Established 192.168.0.106 1515 1393 1465 0 3 22:31:44 Established

//VPE14邻居信息 [VPE14]display bgp peer ipv4 vpn-instance connection-nzy BGP local router ID: 172.171.15.24 Local AS number: 1515 Total number of peers: 1 Peers in established state: 1

    • Dynamically created peer Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State 192.168.0.105 1414 1468 1395 0 5 22:34:01 Established

//VPE5邻居信息 [VPE5]display bgp peer ipv4 vpn-instance fortest BGP local router ID: 44.44.44.44 Local AS number: 444 Total number of peers: 1 Peers in established state: 1

    • Dynamically created peer Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State 192.168.0.105 1414 1734 1489 0 4 22:05:34 Established
  2. 2. **CPE配置负载分担**
  3. ```css
  4. [CPE14]display current-configuration configuration bgp
  5. bgp 1414
  6.  ip vpn-instance connection-nzy
  7.   compare-different-as-med
  8.   peer 192.168.0.2 as-number 444
  9.   peer 192.168.0.2 connect-interface Vsi-interface49
  10.   peer 192.168.0.2 bfd multi-hop
  11.   peer 192.168.0.106 as-number 1515
  12.   peer 192.168.0.106 connect-interface Vsi-interface49
  13.   peer 192.168.0.106 bfd multi-hop
  14.   #
  15.   address-family ipv4 unicast
  16.    balance 8
  17.    balance as-path-neglect
  18.    balance as-path-relax
  19.    preference 5 255 255
  20.    import-route direct
  21.    import-route static
  22.    peer 192.168.0.2 enable
  23.    peer 192.168.0.2 next-hop-local
  24.    peer 192.168.0.106 enable
  25.    peer 192.168.0.106 next-hop-local
  1. VPE发布网段相同静态路由 ```css //VPE14发布1.2.3.0/24 [VPE14]display current-configuration configuration | include static ip route-static vpn-instance connection-nzy 1.2.3.0 24 19.1.1.1

//VPE5发布1.2.3.0/24 [VPE5]display current-configuration configuration | include static ip route-static vpn-instance fortest 1.2.3.0 24 17.1.1.2

  2. 4. **VPE为CPE邻居配置相同MED值**
  3. ```css
  4. //VPE14配置MED为255
  5. [VPE14]display current-configuration configuration bgp
  6. bgp 1515
  7.  ip vpn-instance connection-nzy
  8.   peer 192.168.0.105 as-number 1414
  9.   peer 192.168.0.105 connect-interface Vsi-interface55
  10.   peer 192.168.0.105 bfd multi-hop
  11.   address-family ipv4 unicast
  12.    default med 255
  13.    balance 8
  14.    balance as-path-relax
  15.    preference 5 255 255
  16.    import-route direct
  17.    import-route static
  18.    peer 192.168.0.105 enable
  19.    peer 192.168.0.105 next-hop-local
  21. //VPE5配置MED为255
  22. [VPE5]display current-configuration configuration bgp
  23. bgp 444
  24.  ip vpn-instance fortest
  25.   peer 192.168.0.105 as-number 1414
  26.   peer 192.168.0.105 connect-interface Vsi-interface1
  27.   peer 192.168.0.105 bfd multi-hop
  28.   address-family ipv4 unicast
  29.    default med 255
  30.    balance 8
  31.    balance as-path-relax
  32.    preference 255 255 255
  33.    import-route direct
  34.    import-route static
  35.    peer 192.168.0.105 enable
  36.    peer 192.168.0.105 next-hop-local

  1. CPE此时收到两条1.2.3.0/24等价路由 ```css //CPE14收到两条1.2.3.0/24，均为最优 [CPE6_15.21]display bgp routing-table ipv4 vpn-instance connection-nzy Total number of routes: 11 BGP local router ID is 14.14.14.14 Status codes: * - valid, > - best, d - dampened, h - history,

    1.         s - suppressed, S - stale, i - internal, e - external
    2.         Origin: i - IGP, e - EGP, ? - incomplete

    Network NextHop MED LocPrf PrefVal Path/Ogn

  • e 1.2.3.0/24 192.168.0.2 255 0 444?

  • e 192.168.0.106 255 0 1515?

  • 16.1.1.0/24 16.1.1.1 0 32768 ?

  • 16.1.1.1/32 127.0.0.1 0 32768 ?

  • e 17.1.1.0/24 192.168.0.2 255 0 444?

  • e 19.1.1.0/24 192.168.0.106 255 0 1515?

  • 52.1.1.0/24 16.1.1.2 0 32768 ?

  • 192.168.0.0/16 192.168.0.105 0 32768 ?

  • e 192.168.0.106 255 0 1515?
  • e 192.168.0.2 255 0 444?

  • 192.168.0.105/32 127.0.0.1 0 32768 ?

//CPE14转发表包括两条1.2.3.0/24路由 [CPE6_15.21]display ip routing-table vpn-instance connection-nzy Destinations : 21 Routes : 22 Destination/Mask Proto Pre Cost NextHop Interface 0.0.0.0/0 Static 60 0 172.171.0.1 GE2/0 0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0 1.2.3.0/24 BGP 5 255 192.168.0.2 Vsi49 BGP 5 255 192.168.0.106 Vsi49 16.1.1.0/24 Direct 0 0 16.1.1.1 GE1/0.1006 16.1.1.0/32 Direct 0 0 16.1.1.1 GE1/0.1006 16.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0 16.1.1.255/32 Direct 0 0 16.1.1.1 GE1/0.1006 17.1.1.0/24 BGP 5 255 192.168.0.2 Vsi49 19.1.1.0/24 BGP 5 255 192.168.0.106 Vsi49 52.1.1.0/24 Static 60 0 16.1.1.2 GE1/0.1006 127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0 127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0 127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0 127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0 192.168.0.0/16 Direct 0 0 192.168.0.105 Vsi49 192.168.0.0/32 Direct 0 0 192.168.0.105 Vsi49 192.168.0.105/32 Direct 0 0 127.0.0.1 InLoop0 192.168.255.255/32 Direct 0 0 192.168.0.105 Vsi49 224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0 224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0 255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

  2. 6. **修改VPE14 MED为300，降低路由优先级**
  3. ```css
  4. //VPE14修改MED为300
  5. [VPE14]display current-configuration configuration bgp
  6. bgp 1515
  7.  ip vpn-instance connection-nzy
  8.   peer 192.168.0.105 as-number 1414
  9.   peer 192.168.0.105 connect-interface Vsi-interface55
  10.   peer 192.168.0.105 bfd multi-hop
  11.   address-family ipv4 unicast
  12.    default med 300
  13.    balance 8
  14.    balance as-path-relax
  15.    preference 5 255 255
  16.    import-route direct
  17.    import-route static
  18.    peer 192.168.0.105 enable
  19.    peer 192.168.0.105 next-hop-local

  1. CPE重新择优，MED值较小值优先 ```css //CPE14 1.2.3.0/24路由MED为255最优 [CPE14]display bgp routing-table ipv4 vpn-instance connection-nzy Total number of routes: 11 BGP local router ID is 14.14.14.14 Status codes: * - valid, > - best, d - dampened, h - history,

    1.         s - suppressed, S - stale, i - internal, e - external
    2.         Origin: i - IGP, e - EGP, ? - incomplete

    Network NextHop MED LocPrf PrefVal Path/Ogn

  • e 1.2.3.0/24 192.168.0.2 255 0 444?

  • e 192.168.0.106 300 0 1515?

  • 16.1.1.0/24 16.1.1.1 0 32768 ?

  • 16.1.1.1/32 127.0.0.1 0 32768 ?

  • e 17.1.1.0/24 192.168.0.2 255 0 444?

  • e 19.1.1.0/24 192.168.0.106 300 0 1515?

  • 52.1.1.0/24 16.1.1.2 0 32768 ?

  • 192.168.0.0/16 192.168.0.105 0 32768 ?

  • e 192.168.0.106 300 0 1515?
  • e 192.168.0.2 255 0 444?

  • 192.168.0.105/32 127.0.0.1 0 32768 ?

//CPE14转发面无1.2.3.0/24 ECMP路由 [CPE14]display ip routing-table vpn-instance connection-nzy Destinations : 21 Routes : 21 Destination/Mask Proto Pre Cost NextHop Interface 0.0.0.0/0 Static 60 0 172.171.0.1 GE2/0 0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0 1.2.3.0/24 BGP 5 255 192.168.0.2 Vsi49 16.1.1.0/24 Direct 0 0 16.1.1.1 GE1/0.1006 16.1.1.0/32 Direct 0 0 16.1.1.1 GE1/0.1006 16.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0 16.1.1.255/32 Direct 0 0 16.1.1.1 GE1/0.1006 17.1.1.0/24 BGP 5 255 192.168.0.2 Vsi49 19.1.1.0/24 BGP 5 300 192.168.0.106 Vsi49 52.1.1.0/24 Static 60 0 16.1.1.2 GE1/0.1006 127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0 127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0 127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0 127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0 192.168.0.0/16 Direct 0 0 192.168.0.105 Vsi49 192.168.0.0/32 Direct 0 0 192.168.0.105 Vsi49 192.168.0.105/32 Direct 0 0 127.0.0.1 InLoop0 192.168.255.255/32 Direct 0 0 192.168.0.105 Vsi49 224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0 224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0 255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

```

四、控制器修改点

  • BGP peer南向支持配置负载分担、MED比较策略、AS_PATH比较策略
  • BGP peer南向支持独立配置MED值
  • CPE到VPE 支持多link
  • vrf配置流程改造
  • 静态路由配置流程改造
  • CPE到VPE支持多ipsec policy
  • CPE到VPE支持多tunnel
  • CPE到VPE支持多BGP peer
  • CPE vsi配置流程改造
  • CPE vsi interface配置流程改造