As long as it’s stable you are nowhere near the limits of OSPF as a IGP, and there are a number of fairly simple ways to start to segment the network when you start to reach the limits. OSPF itself is fine but during network instability situations you may run into issues with CPU on some of the underpowered routers which leads to further instability. Overlays of MPLS, VLAN’s, or just OSPF areas can address the issues if you do want to start cutting the size down.
Mark > On Jun 7, 2018, at 3:09 PM, Lewis Bergman <lewis.berg...@gmail.com> wrote: > > Gino would probably be your best source for advice as I'll bet he has one of > the largest networks of similar construction. I think he went MPLS to deal > with a variety of issues he was having, including OSPF. But maybe Gino can > speak up on the issue. > Typically, if you didn't want to do anything else, you would consider iBGP > and break the OSPF domains up in some logical way. The big determining factor > for me for such things is the occurrence route flapping and how often it > happens. Route flapping will be the big indicator that you are to big and > OSPF can't keep up. You can do some tweaking but at some point it just all > falls apart. The bad part about waiting till that happens is you will loose a > lot of customers trying to make things stable again. > I would think Denis also would have a much better informed path to take and > I'll bet he would be happy to contract to help you. Probably money well spent. > > On Thu, Jun 7, 2018 at 1:40 PM Brough Turner <bro...@netblazr.com > <mailto:bro...@netblazr.com>> wrote: > We're an urban WISP with a dense mesh of wireless links and a router per > building. I am concerned that, without paying attention, we have grown to > 600+ routers and ~2550 routes in one OSPF domain. This network has a diverse > mix of routers from CCR1036s down to RB750UPs. We're not having any OSPF > problems at this time and I have plenty of other things to worry about, but > I'd hate to hit some limit and have the whole thing blow up. > > Does anyone have experience (positive or negative) with large flat OSPF > networks? > And, if you have had problems, what were the problems? > Thanks, > Brough > > Brough Turner > netBlazr Inc. – Free your Broadband! > Mobile: 617-285-0433 <tel:(617)%20285-0433> Skype: brough > netBlazr Inc. <http://www.netblazr.com/> | Google+ > <https://plus.google.com/102447512447094746687/posts?hl=en> | Twitter > <https://twitter.com/#%21/brough> | LinkedIn > <http://www.linkedin.com/in/broughturner> | Facebook > <http://www.facebook.com/brough.turner> | Blog > <http://blogs.broughturner.com/> | Personal website > <http://broughturner.com/> > >
