by having multiple areas, therefore ABR which deny routers and network
LSA, you introduce summarization (ABR only send summary LSA, mean subnet
info, not topology info) in your network.
Thus you loose informations and do not have a complete topology of your
network. I guess MPLS/TE prefer to seat on top of a real topology ?
On 22.10.2015 23:22, Bill Blackford wrote:
I don't have all the details because I don't fully understand it, but I've
heard that if you're running an MPLS/RSVP core, you can only use a single
OSPF area. This introduces a scalability ceiling.
On Thu, Oct 22, 2015 at 12:35 PM, Dave Bell <m...@geordish.org> wrote:
On 22 October 2015 at 19:41, Mark Tinka <mark.ti...@seacom.mu> wrote:
The "everything must connect to Area 0" requirement of OSPF was limiting
for me back in 2008.
I'm unsure if this is a serious argument, but its such a poor point
today. Everything has to be connected to a level 2 in IS-IS. If you
want a flat area 0 network in OSPF, go nuts. As long as you are
sensible about what you put in your IGP, both IS-IS and OSPF scale
very well.
The differences between the two protocols are so small, that people
really grasp at straws when 'proving' that one is better over the
other. 'IS-IS doesn't work over IP, so its more secure'. 'IS-IS uses
TLVs so new features are quicker to implement'. While these may be
vaguely valid arguments, they don't hold much water. If you don't
secure your routers to bad actors forming OSPF adjacencies with you,
you're doing something wrong.Who is running code that is so bleeding
edge that feature X might be available for IS-IS, but not OSPF?
Chose whichever you and your operational team are most comfortable
with, and run with it.
Regards,
Dave
