[c-nsp] 3850?

[Mack McBride]

The input queue is the software side of things.
Things that are handled in hardware should be on the no buffer line.
Why are you getting so much software bound traffic?
Things that are getting dropped due to output queueing are going to show as output drops.

http://www.cisco.com/c/en/us/support/docs/switches/catalyst-3750-series-switches/116089-technote-switches-output-drops-qos-00.html

Another place they will show up is the QoS command: sh mls qos interface <interface id> statistics

On these model switches things tend to get dropped due to lack of buffers or output dropped.
If you are having input queue drops it is usually due to things getting sent to software.
Usual suspects are multicast traffic, broadcasts, or routing protocols.
You can also get direct attacks against the switch if it is operating in routed mode.

And in that situation upgrading the switch isn't going to solve the problem.
If it is actually traffic based considering upgrading to a 4948E.
It is a much more capable switch.

Mack McBride | Network Architect | ViaWest, Inc.
O: 720.891.2502 | mack.mcbride at viawest.com | www.viawest.com | LinkedIn | Twitter | YouTube



-----Original Message-----
From: cisco-nsp [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Adam Greene
Sent: Thursday, April 09, 2015 9:17 AM
To: cisco-nsp at puck.nether.net
Subject: [c-nsp] 3850?

Hi all,



We're looking to upgrade some old 3750's and 3750G's whose input queues don't seem to be able to pass 75Mbps without choking:



(on a 3750G)

Last clearing of "show interface" counters 21w5d

Input queue: 1/75/5870052/0 (size/max/drops/flushes); Total output drops:
0).



We need the switches to support:

-          basic QoS policies (mainly, VoIP and routing protocol
prioritization)

-          Flexible NetFlow with NBAR

-          125Mbps aggregate throughput via any given interface now, and
more in the future. If I had to guess, 450Mbps aggregate within 3 years

-          OSPF & BGP



We don't anticipate stacking these.



We're considering:

-          WS-C3850-24T-E (modular)

-          WS-C3650-24TD-E (fixed; 2x10G uplinks)

-          WS-C3650-24TS-E (fixed; 4x1G uplinks)

-          WS-C3560X-24T-E (modular)



I like the idea of the switch being modular, in case we want to put in 10G modules later on, but realistically, can any of these switches even push 1Gbps reliably? After seeing "gigabit" 3750s balk at such low traffic levels, I wonder how much we can really expect any of these switches to push.



Of all the options, the WS-C3850-24T-E seems the most flexible and probably most powerful. I was feeling enthusiastic about the 3560X until someone told me that Flexible NetFlow is supported, but only if you buy the 10G module, which costs as much as the switch itself.



Do you think we're on the right track? Is the WS-C3850-24T-E probably the best fit? How much traffic have you all seen it push in the real world?



Thanks for sharing your experience.



Adam





_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/
This message contains information that may be confidential, privileged or otherwise protected by law from disclosure. It is intended for the exclusive use of the addressee(s). Unless you are the addressee or authorized agent of the addressee, you may not review, copy, distribute or disclose to anyone the message or any information contained within. If you have received this message in error, please contact the sender by electronic reply and immediately delete all copies of the message.