[c-nsp] Cisco 3550 MTU

[Peter Rathlev]

On Mon, 2010-03-29 at 19:23 +1030, Tom Storey wrote:
> The maximum configurable MTU for a 3550 series (excl 3550-12's which  
> can do 2000) is 1546 bytes. Can anyone confirm if this is PAYLOAD  
> size, or raw frame size?

Since the "default" is 1500 bytes, which must be without the outer
802.1q header, I would guess the 1546 bytes MTU is also without the
outer header.

And according to this document:

http://www.cisco.com/en/US/products/hw/switches/ps700/products_configuration_example09186a008010edab.shtml#c4

> Note: The MTU size of 1546 does not include the 18 bytes of the
> standard Ethernet header and FCS. Therefore, these switches actually
> support Ethernet frames up to 1564 bytes.

So I think you're safe.

-- 
Peter