[j-nsp] system maximums for the M and MX series routers

[sthaug at nethelp.no]

>  I need to know the maximum number of L2 and L3VPN supported on MX and M
> series routers.

There is no "System maximums" document for the M / MX series, as far as
I know. We use both M, MX and ERX, and our experience is that parts of
the ERX "System maximums" should be taken with a large grain of salt.
On the other hand, for those cases where we have been able to get real
numbers from Juniper for the M / MX series, our experience is that these
numbers reflect reality much better than the ERX numbers.

For an ERX example, the "System maximums" for JunOSe 9.2.0 states that
the ERX-310 supports a maximum of 1000 virtual routers (or 1000 VRFs)
per chassis. Our experience is that with anything close to a realistic
configuration, where some of the VRFs use DHCP relay, this limit is much
lower, on the order of 150 or so.

Getting back to the M / MX: The maximum number of L2 and L3VPN supported
will depend on a number of factors, for instance number of prefixes and
nexthops, and also on the amount of memory in your forwarding complex
(M7i / M10i can have either 128 MB or 256 MB on the CFEB. The difference
is rather significant).

The only simple answer is, "it depends...".

Steinar Haug, Nethelp consulting, sthaug at nethelp.no