multicast nightmare #42

Thu Oct 15 20:54:04 UTC 2009

As an aside, the 6-port GigE card is not oversubscribed.

Mike

--
Michael K. Smith - CISSP, GISP
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> -----Original Message-----
> From: Philip Lavine [mailto:source_route at yahoo.com]
> Sent: Thursday, October 15, 2009 1:07 PM
> To: Eric Ortega; nanog
> Subject: Re: multicast nightmare #42
> 
> 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
> 
> 
> 