[j-nsp] small multitenant datacenter

[Jeff Wheeler]

On Mon, Dec 3, 2012 at 11:06 PM, Ryan Goldberg <RGoldberg at compudyne.net> wrote:
> Do you see an issue with blowing up ex4200s with all this ospf and vrrp?  I'm labbing tomorrow and will try to get the boxes to thrash.

I'm interested to know your thoughts on RE performance after you have
labbed this scenario.  I've read the EX4200 supports 256 VRF-Lite
instances, but like you, I imagine the control-plane may become
sluggish before it gets to that point.

I noticed you include the EX3300 in your design.  I also considered
this switch and decided against it once I read the feature table.  I
would like to use them once additional features are working, but right
now, it lacks critical items like storm-control.
https://www.juniper.net/techpubs/en_US/release-independent/junos/topics/concept/ex-series-software-features-overview.html

Also, you mention both EX4200 virtual-chassis, and VRRP.  I think it
is unusual to choose BOTH V-C and STP+VRRP as redundancy mechanisms,
because you get "the worst of both worlds" in terms of potential
failure modes.  For example, you get the unknown-unicast problems
associated with ingress traffic arriving on the VRRP non-master and
potentially being flooded out many ports of that switch, because it
may never learn MAC addresses of downstream servers while it is the
non-master.  You also get any problems that you might encounter with
virtual-chassis, meaning, bugs.

I think you should pick one: V-C or STP+VRRP, depending on which
technology you are most comfortable with.  Mixing the two is IMO not
smart, not because of any unique problems that arise from this
combination, but simply because you have decided to expose yourself to
two sets of gotchas without necessarily gaining anything.

My experience with EX4200 virtual-chassis has been extremely good
since Junos 10.4.  Before then, we had problems with file system
corruption on the EX4200, but this was fixed in 10.4.  I have not had
any serious stacking-specific bugs since about Junos 9.5.  I rely
totally on EX4200 virtual-chassis for redundancy in many environments,
and am very pleased with the results.

Good luck with your project.  I hope my comments are constructive and helpful!
-- 
Jeff S Wheeler <jsw at inconcepts.biz>
Sr Network Operator  /  Innovative Network Concepts