Multicast traffic flooding

Hi
We are using Network Load Balancing on some Windows 2003 servers which is configured as IGMP multicast.
The servers are connected to a 3550 SMI switch which is connected to a HP4108.
Before I configured either of these switches I connected a packet sniffer and saw the multicast traffic appearing on all ports on both switches.
I configured the HP switch as a Multicast querier and now on the 3550 I see the multicast mac addresses logged against the server ports. The 3550 also detects the muticast router as you can see:
prod-3550#sh mac-address-table mult
Vlan Mac Address Type Ports
1 0100.5e7f.4601 IGMP Fa0/10, Fa0/12, Gi0/1
1 0100.5e7f.4602 IGMP Fa0/9, Fa0/11, Gi0/1
prod-3550#
prod-3550#sh ip igmp snoo mrouter
Vlan ports
1 Gi0/1(dynamic)
The 3550 is still spamming the multicast traffic to all ports whereas the HP switch is only replicating thisto ports that are part of the multicast group.
Can anyone tell me why the 3550 is doing this or what else I need to check?
Thanks in advance.

Kate
You do not tell us much about how the 3550 is configured. From your description of the problem I am going to assume that you do not have IGMP snooping configured. This link will show you how to configure IGMP on the 3550:
http://www.cisco.com/univercd/cc/td/doc/product/lan/c3550/12225sec/3550scg/swigmp.htm
If my assumption is not correct and you do have IGMP snooping configured, then you will need to tell us more about how the 3550 is configured so we can determine why it is propagating multicast to all ports.
HTH
Rick

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Hi.
There is two switches in the equation:
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tcpdump: WARNING: eth1: no IPv4 address assigned
tcpdump: listening on eth1, link-type EN10MB (Ethernet), capture size 65535 bytes
14:17:37.059045 50:57:a8:f0:72:1b > 33:33:ff:00:00:01, ethertype 802.1Q (0x8100), length 90: vlan 1001, p 0, ethertype IPv6, (class 0xe0, hlim 255, next-header ICMPv6 (58) payload length: 32) 2abc:abc:1:600b::2 > ff02::1:ff00:1: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2abc:abc:1:600b::1
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Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
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Hello
Here is the related configuration and output of show command below,
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*omit
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Best Regards,
Masanobu Hiyoshi

Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
I'm not 100% certain, but I believe FastSwitching and CEF switching apply to unicast, not multicast. Your "IP mroute-cache" command enables/disables fast multicast switching.
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Hello forum,
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Hi Michal,
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However, i've recently been seeing something odd in that there must be some multicast-talking clients on this untrusted network and whatever they are talking about I can see on my management LAN (10.10.10.0). I can basically see multicast packets with source IPs from the untrusted network. How is this possible? More importantly how can I stop it?
All network numbers are just examples. Any help or ideas would be gratefully received.

Hi Stuart,
Just to clarify a point:
"but I didn't think this would matter as the HREAP config would mean that none of this traffic should even leave the access point"
Keep in mind that when an ap is hreap mode, the ap essentially acts like a switch with respect to its ethernet port. When it gets a packet from the wireless side, if appropriate, it tags it and puts it on the wire.
Under ordinary circumstances (unless something is configured to stop this), if a wireless client connected to an hreap ap sends a multicast packet, it absoutely will be put on the wire by the ap, just as a broadcast would. I just confirmed this with lab equipment.
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Load distribution not so even for multicast traffic (ECMP) between a GSR 12410 (XR) and a CRS-1 router

Hi,
I have a scenario in which I see the multicast S,G streams are distributed not so even in the 3 interfaces between a GSR 12404 (XR 3.8.4) and a CRS1 (XR 3.6.2). The multicast mode is SSM.
The total S,G (sources and multicast groups) are 82.
The topology is as follows:
                                               ---link 1--------
Multicast sources ----- CRS1 ---link 2-------- GSR12404------- Receivers
                                                ---link 3--------
From the total of 82 S,G coming from multicast sources, I see the following S,G distribution between the three links:
Link 1: 37 S,G
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Link 3: 24 S,G
The big question is why the Link 1 has very different number of S,G compared to link 2 and link 3?
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multicast-routing
address-family ipv4
interface GigabitEthernet0/2/0/0
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interface GigabitEthernet0/2/1/1
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interface GigabitEthernet0/2/1/2
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nsf
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ssm range SSM
Thanks,
Carlos.

Hi Agherardi,
Did you try to disable your firewall and refer the following KB to confirm you have choose the correct Affinity and Load-Balancing Behavior of the Custom Port Rule.
Specifying the Affinity and Load-Balancing Behavior of the Custom Port Rule
https://technet.microsoft.com/en-us/library/cc759039(v=ws.10).aspx
More information:
Using NLB
https://technet.microsoft.com/en-us/library/bb687542.aspx
I’m glad to be of help to you!
Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact [email protected]

Multicast traffic flooding

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