I have a network with 140 or so OSPF routers, around 1k routes without issues.  
Its not the number of routes, nor the qty of routers, its how much breaks talk 
etc.  The network is very reliable and static for the most part, so OSPF don’t 
chatter too much at all.


Thanks,

Dennis Burgess – Network Engineer/Consutant
MikroTik Certified 
Trianer/Consultant<http://www.linktechs.net/productcart/pc/viewcontent.asp?idpage=5>
 – MTCNA, MTCRE, MTCWE, MTCTCE, MTCINE
Cambium ePMP Certified, Telrad Certified, Cisco CCNA
WISPA – Wireless Internet Service Providers Assoication – Director

For Wireless Hardware/Routers visit www.linktechs.net<http://www.linktechs.net/>
RF Mapping: www.towercoverage.com<http://www.towercoverage.com/>
Office: 314-735-0270
dmburg...@linktechs.net<mailto:dmburg...@linktechs.net>

From: Af [mailto:af-boun...@afmug.com] On Behalf Of Paul Stewart
Sent: Saturday, August 27, 2016 10:53 AM
To: af@afmug.com
Subject: Re: [AFMUG] Mikrotik OSPF weirdness

Very common deployment model … typically in larger networks.

Having said that, and as someone else mentioned I believe, folks often feel 
that OSFP can’t “scale” at all and begin feeling somewhat “forced” into OSPF 
for LB/P2P and iBGP for routes as soon as they get 10,20,30 routers in their 
network and perhaps a couple of hundred subnets.  This is simply not typical 
and OSPF can be much larger in scale before performance is impacted 
significantly

From: Af [mailto:af-boun...@afmug.com] On Behalf Of Jesse DuPont
Sent: August 26, 2016 12:04 AM
To: af@afmug.com<mailto:af@afmug.com>
Subject: Re: [AFMUG] Mikrotik OSPF weirdness

Right, PTP and loopback prefixes are distributed with OSPF (and possibly 
management subnets for radios) and "access" network prefixes (customer-facing) 
are distributed via iBGP.
I have two of my routers configured as BGP route reflectors and all other 
routers peer with only these two; this solves the full mesh and provides 
redundancy.
Jesse DuPont
Network Architect
email: jesse.dup...@celeritycorp.net<mailto:jesse.dup...@celeritycorp.net>
Celerity Networks LLC
Celerity Broadband LLC
Like us! facebook.com/celeritynetworksllc
Like us! facebook.com/celeritybroadband
[cid:image003.png@01D201D0.FC29AA20]
On 8/25/16 8:40 PM, David Milholen wrote:

He may have meant only have the ptp and loopback addresses listed in networks



On 8/25/2016 9:31 PM, Mike Hammett wrote:
I've heard this concept a few times now. I'm not sure how only using OSPF for 
the loopbacks works.


-----
Mike Hammett
Intelligent Computing Solutions<http://www.ics-il.com/>
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________________________________
From: "Bruce Robertson" <br...@pooh.com><mailto:br...@pooh.com>
To: af@afmug.com<mailto:af@afmug.com>
Sent: Thursday, August 25, 2016 6:28:43 PM
Subject: Re: [AFMUG] Mikrotik OSPF weirdness

I've said it before, and been argued with... this is one of many reasons why 
you use iBGP to distribute {customer, dynamic pool, server subnets, anything} 
routes, and use OSPF *only* to distribute router loopback addresses.� All 
your weird OSPF problems will go away.� My apologies if I'm misunderstanding 
the problem, but my point still stands.
On 08/25/2016 10:22 AM, Robert Haas wrote:
Alright, this problem has raised it head again on my network since I started to 
renumber some PPPoE pools.
Customer gets a new IP address via PPPoE x.x.x.208/32 (from x.x.x.192/27 pool). 
Customer can�t surf and I can�t ping them from my office:
�
[office] � [Bernie Router] � [Braggcity Router] � [Ross Router] � 
[Hayti Router] � [customer]
�
A traceroute from my office dies @ the Bernie router but I am not getting any 
type of ICMP response from the Bernie router ie no ICMP Host Unreachable/Dest 
unreachable etc � just blackholes after my office router.
A traceroute from the Customer to the office again dies at the Bernie router 
with no type of response.
�
Checking the routing table on the Bernie router shows a valid route pointing to 
the Braggcity router. It is also in the OSPF LSA�s.
--
Another customer gets x.x.x.207/32 and has no issue at all.
�
--
Force the original customer to a new ip address of x.x.x.205/32 and the service 
starts working again.
�
--
�
Now � even though there is no valid route to x.x.x.208/32 in the routing 
table � traffic destined to the x.x.x.208/32 IP is still getting blackholed.. 
I should be getting a Destination host unreachable from the Bernie router.
�
This is correct the correct response .206 is not being used and there is no 
route to it:
C:\Users\netadmin>ping x.x.x.206
�
Pinging x.x.x.206 with 32 bytes of data:
Reply from y.y.y.1: Destination host unreachable.
Reply from y.y.y.1: Destination host unreachable.
�
Ping statistics for x.x.x.206:
��� Packets: Sent = 2, Received = 2, Lost = 0 (0% loss),
�
C:\Users\netadmin>tracert 74.91.65.206
�
Tracing route to host-x.x.x.206.bpsnetworks.com [x.x.x.206]
over a maximum of 30 hops:
�
� 1���� 6 ms���� 6 ms���� 7 ms� z.z.z.z
� 2���� 6 ms���� 6 ms���� 6 ms� y.bpsnetworks.com 
[y.y.y.1]
� 3� y.bpsnetworks.com [y.y.y.1] �reports: Destination host unreachable.
�
Trace complete.
�
This is what I see to x.x.x.208 even though it is not being used and there is 
no route to it.
C:\Users\netadmin>ping x.x.x.208
�
Pinging x.x.x.208 with 32 bytes of data:
Request timed out.
Request timed out.
�
Ping statistics for x.x.x.208:
��� Packets: Sent = 2, Received = 0, Lost = 2 (100% loss),
�
C:\Users\netadmin>tracert x.x.x.208
�
Tracing route to host-x.x.x.208.bpsnetworks.com [x.x.x.208]
over a maximum of 30 hops:
�
� 1���� 6 ms���� 6 ms���� 6 ms� z.z.z.z
� 2���� *������� *������� *���� 
Request timed out.
� 3���� *������� *���� ^C
�
--
�
I�ve verified there is no firewall that would affect the traffic � I even 
put an accept rule in the forward chain for both the source and destination of 
x.x.x.208 and neither increment at all. So the traffic is not even making out 
of the routing flow and into the firewall..
�
Any pointers are where to start troubleshooting next?
!DSPAM:2,57bf295962076342819562!



--
[cid:image004.jpg@01D201D0.FC29AA20]

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