某局点S5560X-30C-EI 三层组播业务转发不通

组播源S----核心（rp）----（vlan42- bagg1）-汇聚-（vlanif359--bagg9）-- --  pim-sm----- -（vlanif359 – Bagg1） -网关--- （Vlanif 86—bagg2）--------组播接受者

告警信息不涉及

三层组播业务，组播报文延上述组网经RP、汇聚、网关到接受者

但是组网中组播接受者无法获取组播流量

1. 通过流统确认丢包位置发生在汇聚设备上，组播报文进来但是没有出去

2. 检查汇聚设备上的三层组播表项发现组播出接口是vlan86，但是实际应该是vlan359，即组播表项是错误的

 (*, 239.12.21.1)

     RP: 172.18.239.1

     Protocol: pim-sm, Flag: WC 

     UpTime: 11w:5d

     Upstream interface: Vlan-interface42

         Upstream neighbor: 172.18.241.49

         RPF prime neighbor: 172.18.241.49

         Join/Prune FSM: [J] 

     Downstream interface information:

     Total number of downstream interfaces: 2

         1: Vlan-interface86

             Protocol: igmp, UpTime: 11w:5d, Expires: -

             DR state: [NDR]

             Join/Prune FSM: [NI] 

             Assert FSM: [NI]

         2: Vlan-interface359

             Protocol: pim-sm, UpTime: 06:36:39, Expires: 00:02:51

             DR state: [NDR]

             Join/Prune FSM: [J] 

             Assert FSM: [NI]

     FSM information for non-downstream interfaces: None

 (172.18.240.2, 239.12.21.1)

     RP: 172.18.239.1

     Protocol: pim-sm, Flag: ACT 

     UpTime: 11w:5d

     Upstream interface: Vlan-interface42

         Upstream neighbor: 172.18.241.49

         RPF prime neighbor: 172.18.241.49

         Join/Prune FSM: [SPT: NJ] [RPT: NP] 

     Downstream interface information:

     Total number of downstream interfaces: 1

         1: Vlan-interface86

             Protocol: pim-sm, UpTime: 11w:5d, Expires: -

             DR state: [NDR]

             Join/Prune FSM: [SPT: NI] [RPT: NI] 

             Assert FSM: [NI]

     FSM information for non-downstream interfaces:

         1: Vlan-interface359

             Protocol: pim-sm

             DR state: [NDR]

             Join/Prune FSM: [SPT: NI] [RPT: P] 

             Assert FSM: [NI]

下行口放通了vlan 359和vlan700

#

interface Bridge-Aggregation9

 description NHGuiC-AS-XiaN-5560

 port link-type trunk

 undo port trunk permit vlan 1

 port trunk permit vlan 359 700

 link-aggregation mode dynamic

 undo stp enable

#

根据表项状态机来看，vlan 359上的RPT状态为Prune状态，即收到下游设备发送的RPT剪枝报文，

应该是流量到下游设备后，下游设备发起SPT切换，即会先向RP路径发送RPT剪枝报文，并向SPT路径发送剪枝报文，

我司设备正好在RP路径上，所以收到RPT剪枝报文，删除了出接口。

作为下游的网关5560上表项：发生SPT切换，上游邻居是172.18.241.139，即给172.18.241.139发送了加入，但是实际上139是之前配置的地址，在现网中目前没有这个地址

作为网关5560设备，vlan 359的地址是172.18.241.138，只学到了172.18.241.137的pim邻居，

作为汇聚5560设备，vlan359地址是172.18.241.137，只学到了172.18.241.138的pim邻居

网关设备：

(172.18.240.2, 239.12.21.1)

     RP: 172.18.239.1

     Protocol: pim-sm, Flag: RPT SPT NONBR ACT 2MVPN 

     UpTime: 00:01:40

     Upstream interface: Vlan-interface359

         Upstream neighbor: 172.18.241.139

         RPF prime neighbor: NULL

         Join/Prune FSM: [SPT: J] [RPT: P] 

     Downstream interface information:

     Total number of downstream interfaces: 1

         1: Vlan-interface86

             Protocol: pim-sm, UpTime: 00:01:40, Expires: -

             DR state: [NDR]

             Join/Prune FSM: [SPT: NI] [RPT: NI] 

             Assert FSM: [NI]

interface Vlan-interface359

description NHGuiC-AS-XiaN-5560

ip address 172.18.241.138 255.255.255.252

pim sm

isis enable 1

isis ipv6 enable 1

isis circuit-level level-1

isis authentication-mode md5 cipher $c$3$ZgTmVCad25XmF2cTKn9S5Ws8MZYBY7m+p1k=

ipv6 address 240A:400B:625:359::138/64

Neighbor: 172.18.241.137

     Interface: Vlan-interface359

     Uptime: 4d:22h

     Expiry time: 00:01:36

     DR Priority: 1

     Generation ID: 0x71D23755

     Holdtime: 105 s

     LAN delay: 500 ms

     Override interval: 2500 ms

     Neighbor tracking: Disabled

     Bidirectional PIM: Disabled

     RPF proxy vector: Enabled

汇聚5560x上：

interface Vlan-interface359

description NHGuiC-AS-XiaN-5560

ip address 172.18.241.137 255.255.255.252

pim sm

isis enable 1

isis ipv6 enable 1

isis circuit-level level-1

isis authentication-mode md5 cipher $c$3$2EAYPUm9BH36daun0p2kGbQHqbudRRZttGA=

packet-filter 3001 inbound

ipv6 address 240A:400B:625:359::137/64

Neighbor: 172.18.241.138

     Interface: Vlan-interface359

     Uptime: 5d:00h

     Expiry time: 00:01:43

     DR Priority: 1

     Generation ID: 0x288D7A59

     Holdtime: 105 s

     LAN delay: 500 ms

     Override interval: 2500 ms

     Neighbor tracking: Disabled

     Bidirectional PIM: Disabled

     RPF proxy vector: Enabled

检查网关上曾经配置过一条静态地址

 ip route-static 0.0.0.0 0 172.18.241.139

网关设备上目前存在到组播源的路由残留，全局路由表中是 没有的，但是组播学习的 路由还是指向139。导致组播选择的到组播源的路由为之前的缺省路由，又因为这个缺省路由的下一跳当前并不存在，导致组播无法发送PIM加入，从而流量无法转发

[NHGuiC-AS-XiaN-5560-probe]dis multicast rpf-info 172.18.240.2

RPF information about source 172.18.240.2:

     RPF interface: Vlan-interface359, RPF neighbor: 172.18.241.139

     Referenced route/mask: 0.0.0.0/0

     Referenced route type: unicast

     Route selection rule: preference-preferred

     Load splitting rule: disable

     Source AS: 0

     C-multicast route target: 0x0000000000000000

规避方案：

网关设备上：配置一条到组播源的明细路由，下一跳为172.18.241.137

升级当前推荐版本R6628P47版本解决