Hello Stefan: Thanks for your answer, this was a costumer question that i think camed from the way how load balancing in Cisco using Ether Channel was done , in that case you had a fixed number of 8 values so the hashing algorithm (using the source ip , mac ... etc) gives you one of those fixed values. So each one of the links in a bundle was identified with one or several of those values ... so in this case you can only have perfect load balance if you are using 2, 4 or 8 links ... any other combination gives you a not even distribution ...
this is explained here : http://www.cisco.com/en/US/tech/tk389/tk213/technologies_tech_note09186a0080094714.shtml I donĀ“t know how this goes in 802.3ad in Juniper ...what do you think ? , have you ever seen examples of good load balancing using 3 , 5 or 6 links in a bundle ? BR Alexi On Thu, Jan 14, 2010 at 2:04 AM, Stefan Fouant < sfou...@shortestpathfirst.net> wrote: > > -----Original Message----- > > From: juniper-nsp-boun...@puck.nether.net [mailto:juniper-nsp- > > boun...@puck.nether.net] On Behalf Of alexi > > Sent: Wednesday, January 13, 2010 11:45 PM > > To: mti...@globaltransit.net > > Cc: juniper-nsp@puck.nether.net > > Subject: Re: [j-nsp] 802.3ad Question > > > > Hello Mark: > > > > I am coming back to this question , i would apreciate your help again > > ... > > > > in the example you mention you said that your bundle is using 3xGE and > > you > > have a pretty fair load balance 1:1:1 > > do you know if there is any requirement about having pair numbers or > > power > > of 2 amount of links in a bundle to get a good load balance ? > > > > I guess that should depend on the hashing algorithm but of course there > > is > > no much info about how it works .... we are interested to have 6xGE in > > a > > bundle ... so , will we get 6Gbps of real throuhput ...? > > The hashing algorithm Juniper uses is proprietary so there isn't much > useable information out that, but in my experience I've never seen anything > along the lines which would require a LAG to be comprised of multiples of 2 > links to get an even load balance. The load balancing tends to get a more > even distribution when you've got a large number of flows. Assuming a > large > number of flows, you should be able to get an even balance across the > component links within the 802.3ad LAG bundle. You might also want to > consider enabling Layer 4 hashing to get even more granular distribution, > if > the source and destinations are sparse, but you're using a large number of > source and destination ports. > > HTHs. > > Stefan Fouant, CISSP, JNCIE-M/T > www.shortestpathfirst.net > GPG Key ID: 0xB5E3803D > > _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp