I've had pretty bad luck using flex10 modules with multicast market data.
We've had lots of driver related issues and are still fighting with packet
loss which, at least for me, is much harder to debug. Our blades were
running windows and solaris, so you might have better luck if you're
running
] Weird Multicast microburst amplification issue
It definitely looks like a classic microburst output buffer overflow
problem, but with a Sup720 and a 6748 module, I haven't seen this at
this volume. Ticker volume has peeked recently, and that might
contribute to it. It appears to start
This might sound incredibly silly, but in the case I've had better luck with
4900s. They use a single central buffer, so the buffer is effectively
considerably deeper, depending on the specific workload of course.
I've never been quite able to bring myself to use a dell blade chassis, and
Do you have any span sessions enabled?
Dale
Thus spake Matthew Huff (mh...@ox.com) on Fri, Dec 09, 2011 at 01:48:35PM -0500:
We have a multicast data stream (real-time ticker data) that by its nature is
very bursty.
When we connect a source server via gigabit Ethernet to our 6500/sup720
| Phone: 914-460-4039
aim: matthewbhuff | Fax: 914-460-4139
-Original Message-
From: Dale W. Carder [mailto:dwcar...@wisc.edu]
Sent: Monday, December 12, 2011 10:10 AM
To: Matthew Huff
Cc: 'cisco-nsp (cisco-nsp@puck.nether.net)'
Subject: Re: [c-nsp] Weird Multicast
On 12/09/2011 06:48 PM, Matthew Huff wrote:
We have a multicast data stream (real-time ticker data) that by its
nature is very bursty.
When we connect a source server via gigabit Ethernet to our
6500/sup720 switch via a 6748 module and a destination server via
gigabit to the same or different
To: Matthew Huff; 'cisco-nsp'
Subject: RE: [c-nsp] Weird Multicast microburst amplification issue
Hmmm. If it's not spanning tree, I'd have to say it's something not
working right with IGMP, and the server's port is getting more streams
than it should. Have you checked the IGMP port association
Are there multiple streams passing through the switch? A spanning tree
recalculation will cause IGMP to flush associations, and flood all streams
out all ports until they're relearned. Portfast will fix it, as will a
multicast-specific interface command, would need to look it up.
Chuck
, December 09, 2011 2:11 PM
To: Matthew Huff; 'cisco-nsp'
Subject: RE: [c-nsp] Weird Multicast microburst amplification issue
Are there multiple streams passing through the switch? A spanning tree
recalculation will cause IGMP to flush associations, and flood all
streams out all ports until
'; 'cisco-nsp'
Subject: RE: [c-nsp] Weird Multicast microburst amplification issue
Unfortunately, it isn't something simple like that. The output drops are
continuously happening. The network is very stable. There are not other
issues during this time. It's something amplifying the burst of the stream
To: Matthew Huff; 'cisco-nsp'
Subject: RE: [c-nsp] Weird Multicast microburst amplification issue
Can you move the source server over to switch B to see if the problem
still exists on switch B then, or moves to switch A? Anything showing
up in the logs?
Chuck
-Original Message
...@ox.com]
Sent: Friday, December 09, 2011 2:48 PM
To: 'Chuck Church'; 'cisco-nsp'
Subject: RE: [c-nsp] Weird Multicast microburst amplification issue
Yes. The problem only occurs when connected to any other switch than the
source switch. We have over 300 servers, it isn't anything with a specific
-Original Message-
From: Matthew Huff [mailto:mh...@ox.com]
Sent: Friday, December 09, 2011 2:48 PM
To: 'Chuck Church'; 'cisco-nsp'
Subject: RE: [c-nsp] Weird Multicast microburst amplification issue
Yes. The problem only occurs when connected to any other switch than
the source switch
13 matches
Mail list logo
