[c-nsp] EtherChannel on WS-X6148-GE-TX
Matt Buford
matt at overloaded.net
Fri Feb 9 15:54:05 EST 2007
> It's been documented numerous times that WS-X6148-GE-TX can't push more
> than
> 1 Gbps on a given EtherChannel. Is this a per-card limitation? E.g. would
> it
> be possible to push more than 1 Gbps if the EtherChannel member ports were
> on different blades? I'm using a 6509 with Sup1a/MSFC running 12.1E.
Short answer:
If any port within an etherchannel lies within a WS-6148-GE-TX card, that
etherchannel now has a 1gig limit. In fact, it is likely less than 1gig.
These cards are already heavily oversubscribed.
First, understand that there is a 1gig ASIC for every group of 8 ports on
the card.
Second, understand that when you enable Etherchannel, all packets for the
entire bundle are flooded to all member ASICs. It is then up to the ASIC to
filter out and pass on only the packets that are for that specific port.
Combine those two concepts and you can see the limitation. On top of that,
if the other 7 ports in the same ASIC are busy too you can easily end up
with a limitation well below 1gig.
Long answer:
http://www.cisco.com/warp/public/473/4.html#cat6k
scroll down to the "Restrictions" part of this section.
More information about the cisco-nsp
mailing list