[j-nsp] Limit on interfaces in bundle

Michael Hare michael.hare at wisc.edu
Thu Oct 29 14:03:31 EDT 2015


Mark-

re: EoMPLS pw balancing, do you have no-control-word configured?  My understanding [and experience] is that vc is sticky due to hashing based on presence of control word.  If control word is absent you can hash based on normal IP/ethernet headers.  As I recall negative of removing control word has to do with drop optimizations during fragmentation.  I am struggling with same sort of thing for 10G backbone university san replication.  In my case it's because the traffic isn't well hashable even if it were native IP [consistent flow tuple] and short of pressuring vendor to support multiflow transfer, 40G/100G appears to be the only reasonable solution at this point.  

-Michael

example:
    l2circuit {
        neighbor x.y.32.2 {
            interface ge-1/1/0.0 {
                virtual-circuit-id 3115;
                no-control-word; <---
                ignore-mtu-mismatch;
            }


> -----Original Message-----
> From: juniper-nsp [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of
> Mark Tinka
> Sent: Thursday, October 29, 2015 9:19 AM
> To: Saku Ytti <saku at ytti.fi>; Cydon Satyr <cydonsatyr at gmail.com>
> Cc: juniper-nsp at puck.nether.net
> Subject: Re: [j-nsp] Limit on interfaces in bundle
> 
> 
> 
> On 29/Oct/15 16:09, Saku Ytti wrote:
> 
> >
> > JunOS does have these days adaptive balancing, which essentially
> > monitors if one link has higher utilisation than others, then proceeds
> > to give smaller share of hash results to that interface. I don't know
> > how well it works in practice.
> 
> It works okay for IP traffic.
> 
> But we've had issues with it working for Layer 2 traffic which is
> carried in an EoMPLS pw. We had to workaround this by switching from
> "adaptive" to "per-packet". I know what you're thinking - no, we have
> not had any "per-packet"-related issues, as the downlink device to which
> the traffic is being sent is local within the data centre.
> 
> All the hashing features and algorithms that were present simply could
> not handle hashing outbound Layer 2 traffic equally. Juniper seemed to
> indicate some improvements for this in Junos 15, but 14.2 has been super
> stable for us and we'd like to keep it that way.
> 
> Mark.
> _______________________________________________
> juniper-nsp mailing list juniper-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/juniper-nsp


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