[c-nsp] Nexus 5K optimisation for iSCSI traffic

[Matthew Melbourne]

Can P prevent a FEX port being disabled by implementing bpdufilter, or
do we need to ensure that BPDUs aren't receiving on FEX ports?

We were hoping to use LACP between the downstream switch and the FEXes
as a poor-man's loop prevention mechanism.

Cheers,

Matt

On 5 August 2011 15:17, John Gill <johgill at cisco.com> wrote:
> It would be filter toward the FEX ports on your blade switches, but not on
> the FEX ports themselves. Whether you turn STP off or not on the blades, the
> FEX doesn't know. Just remembering if you create a loop, you no longer have
> the protection of STP; you are intentionally tricking the FEX into not
> knowing there is a switch downstream.
>
> Regards,
> John Gill
> cisco
>
> On 8/5/11 9:59 AM, Matthew Melbourne wrote:
>>
>> Thanks for that - that's another issue we've encountered. I am hoping
>> we can implement bpdufilter on the FEX ports (as well as disabling STP
>> on downstream switches).
>>
>> On 5 August 2011 14:12, Brad Hedlund (brhedlun)<brhedlun at cisco.com>
>>  wrote:
>>>
>>> Note that the FEX will disable any port that receives a BPDU, by design
>>> in hardware.  You will need to disable STP on the blade-switch-to-FEX links
>>> for this to work. If it's Cisco blade switches you can use Flex Links.
>>>
>>> Cheers,
>>> Brad
>>> http://bradhedlund.com
>>>
>>> Sent from my iPad
>>> (please excuse brevity, typos)
>>>
>>> On Aug 5, 2011, at 6:08 AM, "Matthew Melbourne"<matt at melbourne.org.uk>
>>>  wrote:
>>>
>>>> Hi,
>>>>
>>>> We're implementing two pairs of N5Ks (and downstream N2k FEXes) to act
>>>> as separate iSCSI SAN fabrics, with SAN heads attached directly to
>>>> N5Ks and host ports (and downstream integrated blade switches)
>>>> connecting to the FEXes. Does anyone have any real-world experience of
>>>> using N5Ks for a large iSCSI deployment. I have enabled jumbo frames
>>>> through a network-qos policy-map as an obvious first-step, but wonder
>>>> whether anything can be optimised by tuning buffer sizes to
>>>> accommodate the bursty nature of iSCSI (etc)? This switches will only
>>>> be switching iSCSI traffic.
>>>>
>>>> Cheers,
>>>>
>>>> Matt
>>>>
>>>> --
>>>> Matthew Melbourne
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>



-- 
Matthew Melbourne