[c-nsp] Multicast packets dropping at 6509

Tony Varriale tvarriale at comcast.net
Tue Oct 30 18:59:39 EDT 2012


On 10/30/2012 7:48 AM, Matthew Huff wrote:
> Do you have pim or igmp snooping turned on?
>
> Without a layer 3 "multicast router" configured, the 6509 will probably shunt the traffic. Setup a SVI interface on that vlan and enable pim dense mode. If you don't want multicast to pass the layer 3 boundry, you can setup a multicast boundry command on the vlan.
>
>
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Ambedkar
> Sent: Tuesday, October 30, 2012 2:23 AM
> To: cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] Multicast packets dropping at 6509
>
> Hi,
> Phil Mayers:
> 1. Data rate:    4 kbps
> 2. Line cards: 1000BaseX supervisor WS-X6K-S2U-MSFC2
>                         1000BaseX Ethernet, WS-X6408A-GBIC
>                          CatOS 8.3
>
> Matthew:
> 1). As we are in the same VLAN, the data is not going to Lyaer-3
> 2). we are using, pim-dense
>
> Null:
> we are not observing such kind of behaviour. what we are observing is that
> one of the switch is not creating any multicast table, when we  see in the
> mac-address table multicast, there is no multicast table. when we replace
> Cisco 6509 with cisco 2950 switch it is working fine.
>
>                                         thank you
>
> On Mon, Oct 29, 2012 at 11:08 PM, null zeroroute
> <nullzero.route at gmail.com>wrote:
>
>> I'm familiar with a bug CSCsk07136 that was found about 4 years ago that
>> causes the multicast table to dump on a hybrid 6500 (catos) every time a
>> port in the same VLAN went down/up.  Basically, all members of a group
>> would lose access to the group every time a port in the same VLAN, on the
>> same 6500, dropped.  I believe the problem was fixed in a later release,
>> however we upgraded to native and no longer experienced the issue.  The
>> only workaround was to statically assign hosts to the required groups.
>>
>>
>> On Mon, Oct 29, 2012 at 6:18 AM, Ambedkar <p.ambedkar at gmail.com> wrote:
>>
>>> Hi,
>>> I am facing a problem in multicast..
>>> The scenario is like this, 2 layer-2 switches(2950) and 1 Layer-1
>>> switch(cisco 6509).
>>> These three switches are connected in series, L2-L3-L2. The problem is the
>>> packets are dropping at L3(Cisco 6509) switch using catOS. The multicast
>>> data is flowing in SAME vlan, means eventhough L3 is there in between, the
>>> data is flowing at layer-2 only.
>>>
>>> Please help me...
>>>
>>> Thanks,
>>> Ambi
>>>
Have a look at this.  Take some time to understand your options.

http://www.cisco.com/en/US/products/hw/switches/ps708/products_tech_note09186a008059a9df.shtml

If you must stay layer 2, I would suggest IMGP querier and then static 
mrouter port.  If you are not familiar with multicast please understand 
what the implications of doing the above are before you get on the CLI.

tv


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