I'm planning to setup a network in one of our locations based on a number of VCs that due to physical limitations have to be connected togetter in a ring topology. I have been searching for a while for protocol alternatives in this situation, or is the only supportet protocol xSTP in the situation? Do Juniper provide any aditional options here? I looked at ERP, but this is not supported by EX3400.
The answer is to use ERPS (G.8032). This is supported on many EX switches, and I "THINK" it should also be there on EX3400, but I am not 100% sure, and documentation is not clear. This support is there on EX4600 and EX4300, as well legacy EX switches, that is why I 'think' it should be there on EX3400. For info see this link:
Since VC itself is actually a ring topology (ISIS under the cover, L2 on top) you could make such a configuration easily with a mixed-chassis of EX4600 and EX4300. Unfortunately, you have EX3400 which can NOT VC with EX4600.
I'd really suggest you discuss your needs (which I assume are some what based on Fiber plant lay-out) with your Juniper Partner or Sales team to come-up with the best approach. Of course xSTP will work for this, but there might be better alternatives depending upon your exact needs.
you are right in your finding regards EX3400. It does not support ERPS which brings you down to classic xSTP.
An option for lowering the impact for a break in the ring could be doing two links on each hop and bundle them together in an aggregated ethernet (ae) interface which keeps the logical link up in case of optics failure or repatch error in a patchpanel. Not pretty but better than nothing.
Alternatively you could look into some (passive) DWDM multiplexers with OADM's beside each EX3400 VC making it possible for you to connect all EX3400 VC's directly to the EX4600 VC via ae's. This would require single mode cabling all over and some extra cost for optics, multiplexers and OADM's...
I ended up going with classic RSTP to get ut up and running, although depending on how long this network is going to be needed, we might "upgrade" it with MSTP.
It is strange that the ES3400 seems to be a "low-end" product, if you look at the feature set and in comparison with smaller brother ex2300 or big-brother ex 4300.
Thanks for all input!