[j-nsp] Running OSPF to manage loopbacks, only have trunks

[Dale Shaw]

Hi Morgan,

On Wed, Aug 31, 2011 at 12:55 PM, Morgan McLean <wrx230 at gmail.com> wrote:
> So for example, if I have a meshed layer 2 network with switches and I would
> like to be able to maintain device reachability using something like OSPF,
> how would I go about doing this? Everything already had two connections to
> its upstream etc, but they are in the form of trunks. Junos won't let me add
> a unit when there is already a unit set as ethernet switching and port mode
> trunk.

OK..

> Is there any way I can create an addressable interface just for point to
> point ospf neighbor relationships, and maintain my ethernet trunks? What I
> don't want to do is run additional cables between everything. I already run
> two uplinks from every access switch into my core switches. I don't want to
> make a giant vlan and put all the devices loopbacks in it, one for
> scalability issues but also for broadcast related issues. I could maybe make
> private vlans between each link, but again thats bad because I'll eventually
> run out of tags! This is just me getting creative at this point, lol.

Could you achieve what you want using RVIs rather than loopback interfaces?

i.e. on your dot1q trunks, carry an extra "management" VLAN and attach
a "family inet" RVI to it?

You wouldn't necessarily need to run OSPF on the RVIs on the edge
switches - depending on your topology. This is how we manage
edge/access switches in L2-only campuses; we have a VLAN 800 carried
on uplinks/trunks with a vlan.800 RVI defined on both the core and
access switches.

On the core side, the vlan.800 interface is part of the OSPF topology
but the interface itself is "passive". On the access side, OSPF
doesn't run at all and the vlan.800 interface in effect makes the
switch appear as an IP-enabled end node/station in VLAN 800.

cheers,
Dale