Yes exactly per my earlier post … everyone wants to jump off the OSPF ship for a couple of reasons:
-Someone told them it’s very bad to scale it up but failed to define what “scale” is referring to -misconfiguration or misunderstanding of OSPF (common) -OS issues (ie. Microtik that’s being talked about a lot) Of course it’s not just about scale … for me, the benefits that BGP brings to the table far outweigh the benefits of OSPF .. ie. OSPF tags vs BGP communities From: Af [mailto:af-boun...@afmug.com] On Behalf Of Faisal Imtiaz Sent: August 26, 2016 6:02 PM To: af@afmug.com Subject: Re: [AFMUG] (OSPF + ibgp) / formerly Mikrotik OSPF weirdness >>As you grow, you'll find it won't scale well. Care to elaborate more on this ? By definition it is pointed out that putting hundreds of routers or hundreds of routes are a weak point of OSPF, however there are many different techniques available to manage that. Regards. Faisal Imtiaz Snappy Internet & Telecom 7266 SW 48 Street Miami, FL 33155 Tel: 305 663 5518 x 232 Help-desk: (305)663-5518 Option 2 or Email: supp...@snappytelecom.net <mailto:supp...@snappytelecom.net> _____ From: "Bruce Robertson" <br...@pooh.com <mailto:br...@pooh.com> > To: af@afmug.com <mailto:af@afmug.com> Sent: Friday, August 26, 2016 5:23:14 PM Subject: Re: [AFMUG] (OSPF + ibgp) / formerly Mikrotik OSPF weirdness As you grow, you'll find it won't scale well. On 08/26/2016 02:21 PM, George Skorup wrote: I do redist with OSPF. It works fine if you know what you're doing. MT OSPF used to act really stupid until ROS v6.27 or thereabouts. On 8/26/2016 2:16 PM, Faisal Imtiaz wrote: So just for the sake of a technical discussion... In your opinion, what is the merit of such a config (osfp + ibgp) ? It can be argued that such a config, a) Still depends on OSPF functioning. b) Layer an additional dynamic protocol on top of it (ibgp) c) Requires additional Routers (route reflectors). If the merit of such an approach is to manage manage OSFP behavior in a more granular fashion, Why not use the those features as they are available in OSPF / Best Practices... (OSFP best practices, suggest that, don't advertise connected or static routes, setup all interfaces as passive, and control prefix advertisements via the network section of OSPF). OSPF also tends to be the most common denominator (protocol) across different mfg. Bgp being the 2nd. Regards Faisal Imtiaz Snappy Internet & Telecom 7266 SW 48 Street Miami, FL 33155 Tel: 305 663 5518 <callto:305%20663%205518> x 232 Help-desk: (305)663-5518 <callto:(305)663-5518> Option 2 or Email: supp...@snappytelecom.net <mailto:supp...@snappytelecom.net> _____ From: "Jesse DuPont" <mailto:jesse.dup...@celeritycorp.net> <jesse.dup...@celeritycorp.net> To: af@afmug.com <mailto:af@afmug.com> Sent: Friday, August 26, 2016 12:03:58 AM 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 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 <http://www.ics-il.com/> Intelligent Computing Solutions <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> <http://www.midwest-ix.com/> Midwest Internet Exchange <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> <http://www.thebrotherswisp.com/> The Brothers WISP <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> _____ From: "Bruce Robertson" <mailto:br...@pooh.com> <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 <callto: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:2,57c0b2eb92841205749441!
