[j-nsp] EX4200 questions

[Bernhard Schmidt]

Hi,

we are a small ISP with a Cisco-only core at the moment, consisting of
two 6500 series and a couple of Cat2960G aggregation switches. We are
looking into deploying to a small IX in the area, which is at the same
location as two of our upstreams. So we are going to throw a second
fiber to the location and put up a small device that can switch GE
linerate for the upstreams and route a couple of 100M to/from the IX
into the backbone. We have been considering the Cisco ME6524 series but
are now looking at the EX4200-24F as well.

Since I don't have much experience with Juniper in general (and with
recent devices like the EX especially) I have a few questions I could
not find answered in the datasheets.

- How is the interoperatibility with Cisco PVSTP+ on L2? I found
  http://www.juniper.net/us/en/local/pdf/implementation-guides/8010002-en.pdf
  which briefly mentions VSTP as being basically the same (and thus fully
  compatible), but then talks in length about how to get standard STP or
  MSTP interoperating with Cisco. Does VSTP "just work" as it does in
  Cisco, plug the device in as you want to and every VLAN gets its own
  tree?

- Datasheet says 16k IPv4 routes and 4k IPv6 routes, I assume this is
  shared space and an IPv6 route just takes four times the resources of
  an IPv4 route?

- Apart from the small FIB, is there any reason why the EX would not be
  suitable for this application? Basically we run a fully-dualstacked
  network, OSPFv2/OSPFv3, BGP, some MPLS/L3VPN (but probably not at this
  location for the time being). I expect at most 30-40 BGP peers with
  total prefix count safely within the limits of the hardware.

Thanks for your answers,
Bernhard