[c-nsp] Flow Control and 10GE interfaces

[Matthew Melbourne]

Hi,

What is the general recommendation regarding enabling flow control on
Ethernet interfaces. Is it a legacy issue when devices had smaller buffers,
or is it still required for specific applications? We are having issues with
an Enterprise NAS solution where servers using it for storage are claiming
to be losing connectivity. The NAS is connected to the switch fabric (a pair
of Catalyst 6509s) by two 2*10GE port-channels (10GBase-SR optics); receive
flow control is enabled on the switch side "flowcontrol receive on", but no
input or output pause frames are being received/sent according to the member
interface statistics. 

The vendor is now suggesting that flowcontrol needs to be enabled end-to-end
- e.g. on aggregation switches downstream from the Catalyst 6509s towards
the servers and on the hosts. However, the utilisation on the NAS
port-channels is only ~400Mbps. Does enabling flowcontrol make sense here?

Cheers,

Matt

-- 
Matthew Melbourne