我在 cisco 4948 上遇到多播问题。
我有带有 muilticast 的 vlan 9，它在多个端口上配置。交换机在所有配置有 vlan 9 的端口上泛洪多播流量。它消耗链路带宽。
据我所知，此模型不支持 IGMP 侦听查询器，因此所有具有 vlan 9 的端口上的所有多播泛洪。据我所知，我需要启用 L3。
我的交换机此时没有启用路由，也没有配置 L3，我尝试启用 L3 以防止泛洪。
conf t
ip multicast-routing
interface Vlan9
ip address 10.22.0.161 255.255.255.128
ip pim sparse-mode
no shutdown
end
end
为了让 IGMP 侦听正常工作，还应该配置什么？
也许我可以让它与一些静态映射一起工作，而无需在交换机上启用 L3？
PS 现在我的交换机没有启用 L3 和多播路由，默认情况下启用了全局监听：
catos#show ip igmp snooping vlan 9
Global IGMP Snooping configuration:
-----------------------------------
IGMP snooping : Enabled
IGMPv3 snooping : Enabled
Report suppression : Enabled
TCN solicit query : Disabled
TCN flood query count : 2
Vlan 9:
--------
IGMP snooping : Enabled
IGMPv2 immediate leave : Disabled
Explicit host tracking : Enabled
Multicast router learning mode : pim-dvmrp
CGMP interoperability mode : IGMP_ONLY
Mrouter 处于上行链路，因为我现在没有配置 L3：
catos#show ip igmp snooping mrouter
Vlan ports
---- -----
9 Po1(dynamic)
在 vlan 配置下根本没有 ip 命令：
catos(config)#vlan 9
catos(config-vlan)#ip?
% Unrecognized command
界面下：
catos(config-vlan)#int vl9
catos(config-if)#ip igmp s?
static-group
以及软件版本：
catos#show version
Cisco IOS Software, Catalyst 4000 L3 Switch Software (cat4000-I5K91S-M), Version 12.2(25)EWA9, RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Wed 21-Mar-07 11:58 by tinhuang
Image text-base: 0x10000000, data-base: 0x115C6158
ROM: 12.2(31r)SGA1
Pod Revision 0, Force Revision 34, Tie Revision 20
Catalyst-2 uptime is 8 weeks, 1 hour, 11 minutes
System returned to ROM by reload
System restarted at 11:09:28 EET Tue Dec 4 2018
System image file is "bootflash:cat4000-i5k91s-mz.122-25.EWA9.bin"
...
cisco WS-C4948-10GE (MPC8540) processor (revision 5) with 262144K bytes of memory.
Processor board ID FOX1233GZE3
MPC8540 CPU at 667Mhz, Fixed Module
顺便说一句，我有另一个这样的开关有同样的问题，但有点另一个软件：
bootflash:cat4500-entservicesk9-mz.122-46.SG.bin"
最后，顺便说一下，我用 rommon 更新了我的开关：
Cisco IOS Software, Catalyst 4500 L3 Switch Software (cat4500-ENTSERVICESK9-M), Version 15.0(2)SG11, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2016 by Cisco Systems, Inc.
Compiled Mon 24-Oct-16 09:48 by prod_rel_team
Image text-base: 0x10000000, data-base: 0x123AECA8
ROM: 12.2(31r)SGA7
Pod Revision 0, Force Revision 31, Gill Revision 20
Catalyst-2 uptime is 4 hours, 18 minutes
System returned to ROM by reload
System image file is "bootflash:cat4500-entservicesk9-mz.150-2.SG11.bin"
Last reload reason: Reload command
现在洪水仍然存在：
#show ip igmp snooping vlan 9 detail
Global IGMP Snooping configuration:
-------------------------------------------
IGMP snooping : Enabled
IGMPv3 snooping : Enabled
Report suppression : Enabled
TCN solicit query : Disabled
TCN flood query count : 2
Last Member Query Interval : 1000
Vlan 9:
--------
IGMP snooping : Enabled
CAPWAP enabled : Disabled
IGMPv2 immediate leave : Disabled
Explicit host tracking : Enabled
Multicast router learning mode : pim-dvmrp
CGMP interoperability mode : IGMP_ONLY
Last Member Query Interval : 1000Topology change : No
# show ip igmp snooping mrouter vlan 9
Vlan ports
---- -----
9 Po7(dynamic), Switch
# show ip igmp snooping querier vlan 9 detail
IP address : 10.0.0.7
IGMP version : v2
Port : Switch
Max response time : 10s
Global IGMP switch querier status
--------------------------------------------------------
admin state : Enabled
admin version : 2
source IP address : 0.0.0.0
query-interval (sec) : 60
max-response-time (sec) : 10
querier-timeout (sec) : 120
tcn query count : 2
tcn query interval (sec) : 10
Vlan 9: IGMP switch querier status
--------------------------------------------------------
elected querier is 10.0.0.7 (this switch querier)
--------------------------------------------------------
admin state : Enabled (state configured)
admin version : 2
source IP address : 10.0.0.7
query-interval (sec) : 60
max-response-time (sec) : 10
querier-timeout (sec) : 120
tcn query count : 2
tcn query interval (sec) : 10
operational state : Querier
operational version : 2
tcn query pending count : 0
# show ip igmp snooping groups vlan 9 count
Total number of groups in Vlan 9: 152
# show ip igmp snooping groups vlan 9
Vlan Group Version Port List
---------------------------------------------------------
9 239.1.0.1 v2 Po7
9 239.1.0.2 v2 Po7
...
9 239.1.0.253 v2 Po7
9 239.1.0.254 v2 Po7
9 239.255.255.250 v2 Po7
10.0.0.7 是我的交换机管理地址，属于本地 VRF。
一些mac多播条目：
#show mac address-table multicast
Multicast Entries
vlan mac address type ports
-------+---------------+-------+--------------------------------------------
9 0100.5e01.0001 igmp Po7
9 0100.5e01.0002 igmp Po7
...
9 0100.5e01.00fe igmp Po7
9 0100.5e7f.fffa igmp Po7
9 ffff.ffff.ffff system Gi1/31,Po7
也许窥探是有效的，但并不像预期的那样。如果设备不需要，其他供应商不会转发流量。还有更多更新的思科型号。
这是来自另一个遭受相同问题的 cisco 4948 的窥探配置。
#show ip igmp snooping vlan 9
Global IGMP Snooping configuration:
-----------------------------------
IGMP snooping : Enabled
IGMPv3 snooping : Enabled
Report suppression : Enabled
TCN solicit query : Disabled
TCN flood query count : 2
Last Member Query Interval : 1000
Vlan 9:
--------
IGMP snooping : Enabled
IGMPv2 immediate leave : Disabled
Explicit host tracking : Enabled
Multicast router learning mode : pim-dvmrp
Last Member Query Interval : 1000
CGMP interoperability mode : IGMP_ONLY
#show mac address-table multicast vlan 9
Multicast Entries
vlan mac address type ports
-------+---------------+-------+--------------------------------------------
9 0100.5e7f.fffa igmp Gi1/42,Po5
9 ffff.ffff.ffff system Gi1/18,Gi1/22,Gi1/24,Gi1/25,Gi1/26,Gi1/28
Gi1/32,Gi1/38,Gi1/39,Gi1/42,Po5
如果你看广告图，流量突发是绝对相同的，但我在 Extreme/EdgeCore 设备上完全没有配置，开箱即用没有这样的问题。来自一个开关的绿色图像，来自完全不同的开关的最后一个图像：
