multicast nightmare #42

Thu Oct 15 20:06:43 UTC 2009

Thank you Eric you are a genius, that has solved and issue that has plagued me for 3 years.

the problem was exactly as you said over subscription of the 8 ports tied to 1 ASIC

________________________________
From: Eric Ortega <eric_ortega at mmi.net>
To: Philip Lavine <source_route at yahoo.com>
Sent: Wed, October 14, 2009 9:51:43 AM
Subject: Re: multicast nightmare #42

Depending on the model of
blade there is an 8-to-1 over subscription on the 4500s. I have had all
kinds of headaches with this myself. The 48 port SFP "gig" blade can
only have 1 gig per each set of 8 ports. The aggregate ports are known
as "gigaports". The layout is gigaport 1 = 1,3,5,7,9,11,13,15 gigaport
2 = 2,4,6,8,10,12,14,16 and so on. I bet that if add up the total
bandwidth in each gigaport you might be over the "limit"

Philip Lavine wrote: 
> 
>I wish that was the case but the switch is a 4500 and the data
>rates are less than 100 mbps on a 1 gig blade/sup
>
>
>
>
________________________________
From: >Eric Ortega <eric_ortega at mmi.net>
>To: Philip Lavine
><source_route at yahoo.com>
>Sent: Wed, October 14,
>2009 8:24:59 AM
>Subject: Re: multicast
>nightmare #42
>
>Are you over subscribing
>either the link or the backplane of the switching device?
>
>>Philip Lavine wrote:
> 
>Please explain how this would be possible:
>>
>>1 sender
>>1 mcast group
>>1 receiver
>>----------------
>> = no data loss
>>
>>1 sender
>>1 mcast group
>>2+ receivers on same VLAN and physical segment
>>--------------------
>>= data loss
>>
>>
>>
>>
>>
>
>-- 
>
>
>Eric R. Ortega
>Network Engineer
>Midcontinent Communications
>605.357.5720
>eric_ortega at gmail.com 
>

-- 

Eric R. Ortega
Network Engineer
Midcontinent Communications
605.357.5720
eric_ortega at gmail.com 