👩‍🌾 🤓 🍓 在Cisco IOS上实施组播VPN（第1部分） 👸🏻 🤴 👩🏼

在了解组织组播VPN的现代方法时，我注意到网络上没有太多材料描述该技术的原理和细节。该供应商的网站上提供了足够的实现配置，但没有说明所有执行的操作的意义。

在本系列文章中，我将尝试揭开所有事物在幕后运作的奥秘。

大约作者假定读者熟悉以下技术：OSPF，BGP，PIM，MPLS。

感兴趣-欢迎在猫之下。

主要任务是在PE路由器之间（从Ingress PE到一个或多个Egress PE）建立组播数据包的隧道。为此，您需要在底层基础结构之上构建一个覆盖网络。

如果我们转向RFC6513，我们将找到关于PE路由器之间必须如何传输流量的相当空间的解释：“必须使用P隧道-P隧道是服务提供商网络内部的一种传输机制，该机制可实例化提供者多播服务接口（PMSI）。PMSI是P网络上概念上的“叠加层”，具有以下属性：给定MVPN中的PE可以将数据包提供给PMSI，并且该数据包将传递到MVPN中的某些或所有其他PE，这样任何接收该数据包的PE都将能够确定该数据包所属的MVPN。”

那些。如果您仅遵循所讲的内容，那么整个多播VPN基础架构将如下所示：

剩下的唯一事情就是弄清楚如何构建此PMSI，以及PE设备如何相互学习。

Protocol Independent Multicast (PIM, P-PIM, Provider-PIM; PIM GRT)
Multipoint Label Distribution Protocol (mLDP)
Resource Reservation Protocol Traffic Engineering (RSVP-TE)
Ingress Replication (IR)

. PMSI PIM mLDP.

-, / . :

PIM (C-PIM, Customer-PIM; PIM (VRF))
BGP.

mVPN :

. (C-Multicast) .

, .

, , :

- (Point-to-Point)
- ( , MPLS ), LSP (unicast) .
- (Point-to-Multipoint)
- ( , root) . (unidirectional).
- (Multipoint-to-Multipoint)
- (bidirectional), , . , .
-- (Point-to-Point-to-Multipoint)
- P2P P2MP . P2P LSP , P2MP .
  
  , Partitioned MDT.

Multi-Directional Inclusive PMSI (MI-PMSI, aka Default MDT)
Selective PMSI (aka Data MDT)
Multi-Directional Selective PMSI (aka Partitioned MDT)

( ). , mVPN «Default MDT».

Default MDT

Default MDT PE- VPN (VRF) . Default MDT , PIM .

Default MDT - PE PIM VRF, PIM (Join/Prune, RPT Switchover) Default MDT , LAN .

mVPN Profile 0

mVPN «Profile 0», «Draft Rosen».

Default MDT
PIM
PIM
C-multicast GRE (mGRE )

, , . :

BGP ( , VPNv4), unicast RPF .
OSPF IS-IS ( ) IP- Loopback0 , BGP
PIM ASM ( Global Routing Table, GRT)
- Bootstrap Router (BSR)
LDP / .

router ospf 1
 router-id X.X.X.X
!
ip mutlicast-routing
!
ip pim register-source Lo0
!
interface Loopback0
 ip address X.X.X.X 255.255.255.255
 ip ospf 1 area 0
 ip pim sparse-mode
!
interface Gi2.Y
 encapsulation dot1q Y
 ip address 10.X.Y.Z 255.255.255.0
 ip ospf 1 area 0
 ip pim sparse-mode
!
router bgp 65001
 bgp router-id X.X.X.X
 no bgp default ipv4 unicast
 neighbor Y.Y.Y.Y remote-as 65001
 neighbor Y.Y.Y.Y update-source Loopback0
 !
 address-family vpnv4
  neighbor Y.Y.Y.Y activate
  neighbor Y.Y.Y.Y send-community-both
!
#############################################
##########     ##########
#############################################
!
ip pim rp-candidate Lo0
ip pim bsr-candidate Lo0

, , ( Provider RP (P-RP) – ). , show ip int brief. ? : Tunnel (encap) PIM-Register P-RP. P-RP Tunnel (decap) Register .

PE1#show int tu2 | i Descr|destination|Tunnel2
Tunnel2 is up, line protocol is up 
  Description: **Pim Register Tunnel (Encap)** for RP 8.8.8.8
  Tunnel source 1.1.1.1 (Loopback0), destination 8.8.8.8

>RR#show int tu0 | i Descr|destination|Tunnel0
Tunnel0 is up, line protocol is up 
  Description: **Pim Register Tunnel (Encap)** for RP 8.8.8.8
  Tunnel source 8.8.8.8 (Loopback0), destination 8.8.8.8
         Tunnel0 source tracking subblock associated with Loopback0
RR#show int tu1 | i Descr|destination|Tunnel1
Tunnel1 is up, line protocol is up 
  Description: Pim Register Tunnel (**Decap**) for RP 8.8.8.8
  Tunnel source 8.8.8.8 (Loopback0), destination 8.8.8.8
         Tunnel1 source tracking subblock associated with Loopback0

Profile 0 C-multicast mGRE . () IP . ( GRT). PIM GRT. :

ip vrf C-ONE
 mdt default 239.1.1.1

, ingress PE - VRF, ingress mGRE, destination IP 239.1.1.1 .

, egress PE . . .

PE2#show ip igmp membership 
Flags: A  - aggregate, T - tracked
       L  - Local, S - static, V - virtual, R - Reported through v3 
       I - v3lite, U - Urd, M - SSM (S,G) channel 
       1,2,3 - The version of IGMP, the group is in
Channel/Group-Flags: 
       / - Filtering entry (Exclude mode (S,G), Include mode (G))
Reporter:
       <mac-or-ip-address> - last reporter if group is not explicitly tracked
       <n>/<m>      - <n> reporter in include mode, <m> reporter in exclude

 Channel/Group                  Reporter        Uptime   Exp.  Flags  Interface 
 *,239.1.1.1                    2.2.2.2         1d20h    stop  2VA    Lo0

, 2 (*, 239.1.1.1) Loopback0. , , PIM Join RP .

, 2 mRIB. PIM ASM (shared tree source-based tree):

P2#show ip mroute 239.1.1.1
IP Multicast Routing Table

(*, 239.1.1.1), 2d00h/00:03:09, RP 8.8.8.8, flags: S
  Incoming interface: GigabitEthernet2.68, RPF nbr 10.6.8.8
  Outgoing interface list:
    GigabitEthernet2.67, Forward/Sparse, 2d00h/00:03:09
    GigabitEthernet2.26, Forward/Sparse, 2d00h/00:03:05
 (2.2.2.2, 239.1.1.1), 05:22:26/00:01:55, flags: T
  Incoming interface: GigabitEthernet2.26, RPF nbr 10.2.6.2
  Outgoing interface list:
    GigabitEthernet2.56, Forward/Sparse, 05:22:26/00:02:46
    GigabitEthernet2.67, Forward/Sparse, 05:22:26/00:03:09

, MDT vrf C-ONE , :

P2#show ip mroute 239.1.1.1
IP Multicast Routing Table
(*, 239.1.1.1), 2d00h/00:03:09, RP 8.8.8.8, flags: S
  Incoming interface: GigabitEthernet2.68, RPF nbr 10.6.8.8
  Outgoing interface list:
    GigabitEthernet2.67, Forward/Sparse, 2d00h/00:03:09
    GigabitEthernet2.26, Forward/Sparse, 2d00h/00:03:05

(4.4.4.4, 239.1.1.1), 05:21:57/00:02:16, flags: T
  Incoming interface: GigabitEthernet2.56, RPF nbr 10.5.6.5
  Outgoing interface list:
    GigabitEthernet2.26, Forward/Sparse, 05:21:57/00:03:15

(3.3.3.3, 239.1.1.1), 05:22:22/00:01:46, flags: T
  Incoming interface: GigabitEthernet2.67, RPF nbr 10.6.7.7
  Outgoing interface list:
    GigabitEthernet2.26, Forward/Sparse, 05:22:22/00:03:05

(2.2.2.2, 239.1.1.1), 05:22:26/00:01:55, flags: T
  Incoming interface: GigabitEthernet2.26, RPF nbr 10.2.6.2
  Outgoing interface list:
    GigabitEthernet2.56, Forward/Sparse, 05:22:26/00:02:46
    GigabitEthernet2.67, Forward/Sparse, 05:22:26/00:03:09

(1.1.1.1, 239.1.1.1), 2d00h/00:03:15, flags: T
  Incoming interface: GigabitEthernet2.56, RPF nbr 10.5.6.5
  Outgoing interface list:
    GigabitEthernet2.26, Forward/Sparse, 2d00h/00:03:05

GRT. ? — C-VRF! .

PMSI. Cisco IOS ( Profile 0) MDT BGP. MDT , PMSI .

MDT Route Reflector (R8).

PE1#sh run | s bgp
router bgp 65001
 !
 address-family ipv4 mdt
  neighbor 8.8.8.8 activate
 exit-address-family

Tunnel:

*Nov 12 11:27:45.131: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel0, changed state to up

PE1#show int Tu0 | i transport|source|Tunnel0
Tunnel0 is up, line protocol is up 
  Tunnel source 1.1.1.1 (Loopback0)
         Tunnel0 source tracking subblock associated with Loopback0
          Set of tunnels with source Loopback0, 2 members (includes iterators), on interface <OK>
  Tunnel protocol/transport multi-GRE/IP
  Tunnel transport MTU 1476 bytes

Tunnel0 — , PMSI C-VRF.

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          Tunnel0                  v2/S   3      30     1          4.4.4.4

PIM Hello ( 224.0.0.13) , VRF Default MDT.

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          Tunnel0                  v2/S   3      30     1          4.4.4.4

PE1#show ip pim vrf C-ONE neighbor           
PIM Neighbor Table
Mode: B - Bidir Capable, DR - Designated Router, N - Default DR Priority,
      P - Proxy Capable, S - State Refresh Capable, G - GenID Capable,
      L - DR Load-balancing Capable
Neighbor          Interface                Uptime/Expires    Ver   DR
Address                                                            Prio/Mode
172.1.11.11       GigabitEthernet2.111     4d20h/00:01:25    v2    1 / DR S P G
172.1.15.15       GigabitEthernet2.115     4d21h/00:01:25    v2    1 / DR S P G
3.3.3.3           Tunnel0                  00:07:25/00:01:41 v2    1 / S P G
2.2.2.2           Tunnel0                  00:07:25/00:01:41 v2    1 / S P G
4.4.4.4           Tunnel0                  00:08:24/00:01:41 v2    1 / DR S P G

PIM Hello, 1. , ( VRF) IP-, .

, Default MDT Multipoint-to-Multipoint .. (. PIM Hello) , .

: « MDT? PIM ASM ».

, Cisco IOS , PMSI BGP . , (Tunnel0 UP neighbor activate).

MDT , PIM SSM. , RP, - . MDT :

PE1#show bgp ipv4 mdt all 
     Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 1.1.1.1:1 (default for vrf C-ONE)
 *>   1.1.1.1/32       0.0.0.0                                0 ?
Route Distinguisher: 2.2.2.2:1
 *>i  2.2.2.2/32       2.2.2.2                  0    100      0 ?
Route Distinguisher: 3.3.3.3:1
 *>i  3.3.3.3/32       3.3.3.3                  0    100      0 ?
Route Distinguisher: 4.4.4.4:1
 *>i  4.4.4.4/32       4.4.4.4                  0    100      0 ?

PE1#show bgp ipv4 mdt all 2.2.2.2/32
BGP routing table entry for 2.2.2.2:1:2.2.2.2/32         version 3
Paths: (1 available, best #1, table IPv4-MDT-BGP-Table)
  Not advertised to any peer
  Refresh Epoch 1
  Local
    2.2.2.2 from 8.8.8.8 (8.8.8.8)
      Origin incomplete, metric 0, localpref 100, valid, internal, best
      Originator: 2.2.2.2, Cluster list: 8.8.8.8,
      MDT group address: 239.1.1.1

      rx pathid: 0, tx pathid: 0x0

Originator MDT group address, (S,G) .

. : The Address Family (AF) IPv4 Multicast Distribution Tree (MDT) must be used for all types of PIM signaling in the core (not only for PIM Source Specific Multicast (SSM)).

.. sAFI MDT , .

, CE3 CE4 :

interface Loopback0
 ip igmp join-group 230.0.0.1

, 3 4 :

PE3#show ip mroute vrf C-ONE       

(*, 230.0.0.1), 05:58:36/00:03:19, RP 15.15.15.15, flags: S
  Incoming interface: Tunnel1, RPF nbr 1.1.1.1
  Outgoing interface list:
    GigabitEthernet2.313, Forward/Sparse, 00:00:10/00:03:19

PE4#show ip mroute vrf C-ONE

(*, 230.0.0.1), 00:00:29/00:03:00, RP 15.15.15.15, flags: S
  Incoming interface: Tunnel0, RPF nbr 1.1.1.1
  Outgoing interface list:
    GigabitEthernet2.414, Forward/Sparse, 00:00:29/00:03:00

2 OIL ( ). , IIL Tunnel (default MDT). .. 2 230.0.0.1 .

PE2#show ip mroute 239.1.1.1

(*, 239.1.1.1), 05:06:26/stopped, RP 8.8.8.8, flags: SJCFZ
  Incoming interface: GigabitEthernet2.26, RPF nbr 10.2.6.6
  Outgoing interface list:
    MVRF C-ONE, Forward/Sparse, 05:06:26/stopped

PE2#show ip mroute vrf C-ONE

(*, 230.0.0.1), 05:59:17/00:01:08, RP 15.15.15.15, flags: SP
  Incoming interface: Tunnel1, RPF nbr 1.1.1.1
  Outgoing interface list: Null

CE1#ping 230.0.0.1 source 11.11.11.11
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, 11 ms
Reply to request 0 from 13.13.13.13, 13 ms

, , PIM ( mGRE):

: MPLS , ( Profile 0) .

(ICMP reply) MPLS L3 VPN:

, Default MDT . , PE-, , C-Receiver . , PE, . ( VLAN ID = 26, R2 (PE2) R6 (P2)).

为了绕过默认MDT的局限性，引入了数据MDT的概念，该概念允许将用户流量C-（S，G）从默认MDT切换到数据MDT，其中仅涉及那些存在活动流量源或接收者的PE。下期我们将与您讨论。

未完待续...

在Cisco IOS上实施组播VPN（第1部分）

Default MDT

mVPN Profile 0

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