[cisco-voip] speaker sends ttl=16, switch drops it

[Scott Voll]

berbee InformaCast

Rossella--

Does the Altas speaker have a firmware on it you can get and update?

Scott

On Mon, Jun 16, 2008 at 9:49 AM, Wes Sisk <wsisk at cisco.com> wrote:

> Rossella,
>
> Good problem.  The RFC appears to indicate:
> http://www.faqs.org/rfcs/rfc2236.html
> "All IGMP messages described in this document are sent with IP
>  TTL 1, and contain the IP Router Alert option [RFC 2113] in their IP
>  header."
>
> The switch is being a bit aggressive in interpretation, but I'd say the
> speaker is out of order here.  When you say "speaker gets all its
> configuration parameters from the server". What server do you mean?
>
> Regards,
> Wes
>
>
> Rossella Mariotti-Jones wrote:
>
>> Hello all, I've been approaching this issue from many different sides, so
>> I figured I'd post on this list too.
>> The players are: an Atlas Sound ip speaker model I128SYS (ceiling), a
>> Foundry switch, and Berbee InformaCast v.5.1.1.
>> The speaker sends multicast membership group report with ttl=16, as soon
>> as it gets to the switch it gets dropped, see the switch message below:
>> IGMP: Error! ttl=16 (!= 1), discard, pkt S=10.22.3.54 to 239.0.1.2, on
>> VL221 (phy 0/1/37), igmp_size=8
>> Foundry says that per RFC 2236, IGMP version 2 Membership Report to the
>> group is sent with IP TTL of 1, so whatever is not equal to 1 gets
>> discarded.
>> According to Berbee tech support the speaker gets all its configuration
>> parameters from the server however modifying the ttl on the server doesn't
>> change the ttl value that the speaker uses when sending the membership group
>> report, so we think this is a value that's coded in the speaker's firmware.
>> The speaker works flawlessly on a Cisco switch. We have already put in a
>> feature request with Foundry because we think the problem is how they are
>> enforcing the RFC, in the meantime we are looking for a different kind of
>> ceiling speakers to try on these switches, any suggestions on any of these
>> points? Anybody has or has had something similar happening?
>> Thanks in advance.
>> ***
>> Rossella Mariotti-Jones
>> rossella at chemeketa.edu
>>
>>
>> Network Analyst, SS - SPIR - IT TAC
>> desk 503-589-7775 - cell 503-480-4255
>>
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