Clever Geek Handbook

在Cisco IOS上实施多播VPN（第2部分-配置文件1）

在上一篇文章中，我们遇到了历史上第一种使用PIM和mGRE技术组织组播VPN构建的方法（第1部分，配置文件0）。



如今，有多种方法可以在骨干网上运行P-PIM。特别是，mLDP协议可用于组织多播树。让我们看看它是如何工作的。但是首先，让我们记住LDP的基本概念。



  • LDP对等体通过向224.0.0.2发送Hello消息来找到对方。作为Hello的一部分，将传输“传输地址”参数（默认情况下，在Cisco IOS中该参数与LDP路由器ID的IP地址一致）
  • 路由器建立TCP会话并交换FEC的标签（从路由表中读取-IP前缀）
  • 交换结果是点对点单向LSP。




  • 另外，TCP会话中的对等方交换初始化类型的消息，在该消息中传输有关支持的功能（Capabilities）的信息。功能TLV负责信息交换。

    • 那些。您不仅可以交换有关P2P LSP的信息，还可以交换其他信息...


对于本协议，mLDP的全部意义在于，FEC不仅是一个特定的前缀，而且是四个元素的组合：



  • 树型
  • (IPv4/IPv6)
  • IP
  • — , mLDP LSP
  • , «Opaque Value».

    • ( C-VRF) MPLS .


mLDP FEC:



  • P2MP FEC ( = 0x06)
  • MP2MP Upstream FEC ( = 0x07)
  • MP2MP Downstream FEC ( = 0x08)


P2MP , () . . .. . LSP P2MP :





MP2MP , (, ). : , . LSP MP2MP :





, MP2MP LSP mLDP (P2MP ).



MP2MP LSP



unicast LSP, ( ) .



( PIM ASM ):



  • Downstream

    • ,
  • Upstream

    • ,




, , Downstream, Upstream . ( , ). ( ) - , ( ).



Default MDT BGP ipv4 MDT mLDP :





R8.



(, 1- ):



  • PIM: 



    interface Gi2.X
no ip pim sparse-mode
<br>
  • BGP MDT ( ): 



    router bgp 65001
no address-family ipv4 mdt
  • MDT 



    ip vrf C-ONE
no mdt default 239.1.1.1


FEC IP Opaque Value. 1:



PE1(config)#mpls mldp logging notifications
PE1(config)#!
PE1(config)#ip vrf C-ONE
PE1(config-vrf)# vpn id 65001:1
PE1(config-vrf)# mdt default mpls mldp 8.8.8.8
PE1(config-vrf)#
*Nov 21 22:41:03.703: %MLDP-5-ADD_BRANCH: [mdt 65001:1 0] Root: 8.8.8.8, Add MP2MP branch MDT(Lspvif0) remote label , local label no_label
*Nov 21 22:41:03.742: MLDP: Reevaluating peers for nhop: 10.1.5.5
PE1(config-vrf)#
*Nov 21 22:41:04.647: %LINEPROTO-5-UPDOWN: Line protocol on Interface Lspvif0, changed state to up
PE1(config-vrf)#
*Nov 21 22:41:05.840: %PIM-5-DRCHG: VRF C-ONE: DR change from neighbor 0.0.0.0 to 1.1.1.1 on interface Lspvif0
PE1(config-vrf)#


PE1 Lspvif0 (LSP virtual interface, PMSI) MDT Opaque Value = [65001:1 0] PIM C-VRF.



. Opaque Value : vpn id . , Default MDT.



:



PE1#show ip interface Lspvif0
Lspvif0 is up, line protocol is up
  Interface is unnumbered. Using address of Loopback0 (1.1.1.1)
  Multicast reserved groups joined: 224.0.0.1 224.0.0.2 224.0.0.22 224.0.0.13
  VPN Routing/Forwarding "C-ONE"


PE1#show ip pim vrf C-ONE interface 

Address          Interface                Ver/   Nbr    Query  DR         DR
                                          Mode   Count  Intvl  Prior
172.1.11.1       GigabitEthernet2.111     v2/S   1      30     1          172.1.11.11
172.1.15.1       GigabitEthernet2.115     v2/S   1      30     1          172.1.15.15
1.1.1.1          Lspvif0                  v2/S   0      30     1          1.1.1.1


:



PE1#show mpls mldp neighbors 

 MLDP peer ID    : 5.5.5.5:0, uptime 2w0d Up, 
  Target Adj     : No
  Session hndl   : 1
  Upstream count : 1
  Branch count   : 0
  Path count     : 1
  Path(s)        : 10.1.5.5          LDP GigabitEthernet2.15
  Nhop count     : 1
  Nhop list      : 10.1.5.5 


PE1#show mpls mldp database 
  * For interface indicates MLDP recursive forwarding is enabled
  * For RPF-ID indicates wildcard value
  > Indicates it is a Primary MLDP MDT Branch

LSM ID : 5 (RNR LSM ID: 6)   Type: MP2MP   Uptime : 00:07:53
  FEC Root           : 8.8.8.8 
  Opaque decoded     : [mdt 65001:1 0] 
  Opaque length      : 11 bytes
  Opaque value       : 02 000B 0650010000000100000000
  RNR active LSP     : (this entry)
  Upstream client(s) :
    5.5.5.5:0    [Active]
      Expires        : Never         Path Set ID  : 6
      Out Label (U)  : 1013          Interface    : GigabitEthernet2.15*
      Local Label (D): 10017         Next Hop     : 10.1.5.5
  Replication client(s): 
>   MDT  (VRF C-ONE)
      Uptime         : 00:07:53      Path Set ID  : 7
      Interface      : Lspvif0       RPF-ID       : *


1 Upstream , 10017. , 1 R8 1013 1.



1 ( — ):



P1#show mpls mldp neighbors 

 MLDP peer ID    : 4.4.4.4:0, uptime 2w0d Up, 
  Target Adj     : No
  Session hndl   : 1
  Upstream count : 0
  Branch count   : 0
  Path count     : 1
  Path(s)        : 10.4.5.4          LDP GigabitEthernet2.45
  Nhop count     : 0

 MLDP peer ID    : 1.1.1.1:0, uptime 2w0d Up, 
  Target Adj     : No
  Session hndl   : 2
  Upstream count : 0
  Branch count   : 1
  Path count     : 1
  Path(s)        : 10.1.5.1          LDP GigabitEthernet2.15
  Nhop count     : 0

 MLDP peer ID    : 8.8.8.8:0, uptime 2w0d Up, 
  Target Adj     : No
  Session hndl   : 3
  Upstream count : 1
  Branch count   : 0
  Path count     : 1
  Path(s)        : 10.5.8.8          LDP GigabitEthernet2.58
  Nhop count     : 1
  Nhop list      : 10.5.8.8 

 MLDP peer ID    : 6.6.6.6:0, uptime 2w0d Up, 
  Target Adj     : No
  Session hndl   : 4
  Upstream count : 0
  Branch count   : 0
  Path count     : 1
  Path(s)        : 10.5.6.6          LDP GigabitEthernet2.56
  Nhop count     : 0

 MLDP peer ID    : 7.7.7.7:0, uptime 2w0d Up, 
  Target Adj     : No
  Session hndl   : 5
  Upstream count : 0
  Branch count   : 0
  Path count     : 1
  Path(s)        : 10.5.7.7          LDP GigabitEthernet2.57
  Nhop count     : 0

 MLDP peer ID    : 9.9.9.9:0, uptime 1w5d Up, 
  Target Adj     : No
  Session hndl   : 6
  Upstream count : 0
  Branch count   : 0
  Path count     : 1
  Path(s)        : 10.5.9.9          LDP GigabitEthernet2.59
  Nhop count     : 0


P1#show mpls mldp database 
  * For interface indicates MLDP recursive forwarding is enabled
  * For RPF-ID indicates wildcard value
  > Indicates it is a Primary MLDP MDT Branch

LSM ID : 3   Type: MP2MP   Uptime : 00:13:23
  FEC Root           : 8.8.8.8 
  Opaque decoded     : [mdt 65001:1 0] 
  Opaque length      : 11 bytes
  Opaque value       : 02 000B 0650010000000100000000
  Upstream client(s) :
    8.8.8.8:0    [Active]
      Expires        : Never         Path Set ID  : 9
      Out Label (U)  : 8017          Interface    : GigabitEthernet2.58*
      Local Label (D): 1014          Next Hop     : 10.5.8.8
  Replication client(s): 
    1.1.1.1:0 
      Uptime         : 00:13:23      Path Set ID  : A
      Out label (D)  : 10017         Interface    : GigabitEthernet2.15*
      Local label (U): 1013          Next Hop     : 10.1.5.1


, 1 C-VRF , MP2MP - recursive fec.



1 Upstream (, ) Downstream . 1, , 10017. mLDP 10017, 1 1014 Upstream .





: , Downstream MP2MP , Upstream MP2MP Upstream .



ROOT.



1014, ROOT 8017 1 Upstream . 8017, 1 Downstream 1013 PE1.





4:



PE4(config-subif)#ip vrf C-ONE
PE4(config-vrf)# vpn id 65001:1
PE4(config-vrf)# mdt default mpls mldp 8.8.8.8


*Nov 21 23:25:03.638: %PIM-5-NBRCHG: VRF C-ONE: neighbor 1.1.1.1 UP on interface Lspvif0


, mLDP R8 (ROOT) . - , 1 4 , 4 FEC, PE1.



1 ( , .. 4 ):



P1#show mpls mldp database             
  * For interface indicates MLDP recursive forwarding is enabled
  * For RPF-ID indicates wildcard value
  > Indicates it is a Primary MLDP MDT Branch

LSM ID : 3   Type: MP2MP   Uptime : 00:46:10
  FEC Root           : 8.8.8.8 
  Opaque decoded     : [mdt 65001:1 0] 
  Opaque length      : 11 bytes
  Opaque value       : 02 000B 0650010000000100000000
  Upstream client(s) :
    8.8.8.8:0    [Active]
      Expires        : Never         Path Set ID  : 9
      Out Label (U)  : 8017          Interface    : GigabitEthernet2.58*
      Local Label (D): 1014          Next Hop     : 10.5.8.8
  Replication client(s): 
    1.1.1.1:0 
      Uptime         : 00:46:10      Path Set ID  : A
      Out label (D)  : 10017         Interface    : GigabitEthernet2.15*
      Local label (U): 1013          Next Hop     : 10.1.5.1
    4.4.4.4:0 
      Uptime         : 00:02:11      Path Set ID  : B
      Out label (D)  : 40017         Interface    : GigabitEthernet2.45*
      Local label (U): 1012          Next Hop     : 10.4.5.4




VRF C-TWO 4, .



PE4(config)#ip vrf C-TWO
PE4(config-vrf)# rd 4.4.4.4:2
PE4(config-vrf)# vpn id 65001:2
PE4(config-vrf)# mdt default mpls mldp 8.8.8.8
PE4(config-vrf)# route-target export 65001:2
PE4(config-vrf)# route-target import 65001:2


RR#show mpls mldp database 
  * For interface indicates MLDP recursive forwarding is enabled
  * For RPF-ID indicates wildcard value
  > Indicates it is a Primary MLDP MDT Branch

LSM ID : 1   Type: MP2MP   Uptime : 00:54:07
  FEC Root           : 8.8.8.8 (we are the root)
  Opaque decoded     : [mdt 65001:1 0] 
  Opaque length      : 11 bytes
  Opaque value       : 02 000B 0650010000000100000000
  Upstream client(s) :
    None
      Expires        : N/A           Path Set ID  : 1
  Replication client(s): 
    5.5.5.5:0 
      Uptime         : 00:54:06      Path Set ID  : 2
      Out label (D)  : 1014          Interface    : GigabitEthernet2.58*
      Local label (U): 8017          Next Hop     : 10.5.8.5

LSM ID : 2   Type: MP2MP   Uptime : 00:00:48
  FEC Root           : 8.8.8.8 (we are the root)
  Opaque decoded     : [mdt 65001:2 0] 
  Opaque length      : 11 bytes
  Opaque value       : 02 000B 0650010000000200000000
  Upstream client(s) :
    None
      Expires        : N/A           Path Set ID  : 3
  Replication client(s): 
    5.5.5.5:0 
      Uptime         : 00:00:48      Path Set ID  : 4
      Out label (D)  : 1019          Interface    : GigabitEthernet2.58*
      Local label (U): 8018          Next Hop     : 10.5.8.5


, 1 4.



CE1#ping 230.0.0.1 source Lo0
Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 230.0.0.1, timeout is 2 seconds:
Packet sent with a source address of 11.11.11.11 

Reply to request 0 from 14.14.14.14, 15 ms


, . , — ? ( U-turn) P1 4?



, 1 ROOT Wireshark.



, 1 1013 ( ) ( 802.1Q vlan id = 15). .





1 ?



P1#show mpls forwarding-table labels 1013
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop    
Label      Label      or Tunnel Id     Switched      interface              
1013       8017       [mdt 65001:1 0]  198024        Gi2.58     10.5.8.8    
           40017      [mdt 65001:1 0]  184856        Gi2.45     10.4.5.4


. P1 , . ( show mpls mldp database ). , ROOT, ROOT . , 1, «» 4 ROOT. . U-turn - , 1



  • Downstream 4
  • Upstream 1


1 MPLS , ROOT «» .



ROOT :



RR#show mpls forwarding-table | i 8017
8017       No Label   [mdt 65001:1 0]  0


VRF . Lspvif PIM .



PE1#show ip pim vrf C-ONE neighbor | i Lsp
3.3.3.3           Lspvif0                  00:01:02/00:01:41 v2    1 / S P G
2.2.2.2           Lspvif0                  00:01:09/00:01:40 v2    1 / S P G
4.4.4.4           Lspvif0                  10:49:57/00:01:40 v2    1 / DR S P G


, ROOT , 8017 ( 1) .



RR#show mpls forwarding-table | i 8017
8017       2013       [mdt 65001:1 0]  982           Gi2.68     10.6.8.6




multicast VPN «Profile 1». :



  • P-PIM
  • PMSTI Lspvif
  • BGP
  • Default MDT
  • Default MDT mLDP.

    • , ( VPN) , Profile 0.
  • C-VRF PIM ( Lspvif)


...



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