we replaced our existing 3750 stack (4 3750's with GE connections) with a 6509.
Since then I see massive output packet drops on interfaces. I checked the forum and many people are talking about line cards (WS-X6548-GE-TX), which might be the reason. But the load rarely goes over 100Mbits on those interfaces and I still see drops in the range of 10% on the overall traffic.
For testing I removed all QoS config from the interfaces, but it had no positive effect. I am really looking for help on this.
the WS-X6548-GE-TX is designed to "share" 1Gig for groups of 8 ports - this is referred as an 8:1 oversubscription.
i.e. if you load up ports 1 to 8 with heavily utilized servers, this will cause drops.
Cisco recommends using the newer WS-X6748-GE-TX modules which use a matrix to achieve far better "over-subscription" ratios depending upon specific placements within the chassis. This of, course means extra cost and requires a specific IOS code on the Sup 720.
Now, if this route is not cost effective for your company, you can try configuring traffic flow control on indivdual ports/servers and/or ensure the heavy hitting servers are not on a common ASIC (which controls each indvidual group of 8 ports).
Many companies, including mine, still use the WS-X6548-GE-TX for server connections and we found using flow control for specific servers helped prevent the drops.
the matrix design on the newer line card can give up to 40G per port (pending placement in the 6509 - E chassis). However, nothing less than 20G is provisioned which takes the 8:1 oversubscription down to around 2.1:1 oversubscription - far better but is chassis specific & IOS specific. i.e. probably worth the investment for a net new Data Centre switch but may not be worth upgrading an existing one.
I'm on the hunt for the Cisco link and will post it if I can find it.
Details on the new line card and the use of a fabric matrix were done via a direct technical session with Cisco and I'm not aware of any links that detail how the new line card functions.
I would recommend that if anyone is considering new 6509-E switches for a Data Centre environment that you arrange a technical session with your Cisco reps. to determine the specific requirements and cost.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.