[j-nsp] Best practice MTU?

[Colin Whittaker]

On Fri, Apr 27, 2012 at 07:40:43AM -0500, Eric Helm wrote:
> 
> 
> On 4/26/2012 4:32 PM, OBrien, Will wrote:
> > We've been pushing out jumbo frames across our new core lately. Right now I've got multiple boxes from multiple vendors that all support different maximum MTUs.
> > 
> > Example: Juniper MX960/480, Nexus 7009, Nexus 5k/2k, Catalyst 4900, Nortel/Avaya 8600.... All different maximums.
> > 
> > Anyone have suggestions for a best practice MTU? (That is.... over 9000?!)
> 
> I just ran across this the other day. Some good reading and looks like a
> push to standardize 9000 byte MTU across the board.
> 
> https://ripe64.ripe.net/presentations/139-Hurricane_Electric_-_Martin_Levy_-_IX_Jumbo_Frames_-_RIPE64_EIX-WG_-_Slovenia.pdf
> http://www.ietf.org/id/draft-mlevy-ixp-jumboframes-00.txt

9000 for IP mtu provided to end users / customers is a nice round
number.

I have started using 9100 as the internal mtu as it leaves 100
bytes for any encap overhead you might want from mpls/gre/etc and is
easy to remember.

Colin

-- 
Colin Whittaker					+353 (0)86 8211 965
http://colin.netech.ie			            colin at netech.ie