Most of the time you are trying to solve the issue (distributing a subnet) incorrectly by distributing the connected routes. Not stating that you can't do it, but 99% of the time there is a better way without the "gotchas" that come with that..
1. Customer distributing connected routes. OSPF is SLOW to update, as they are constantly updating, 192.168.200.0/24 between ALL of his sites, just like you said, it was a management subnet and they were all active at the same time. Constant updates means OSPF runs slow. Why, he did not want to put what networks he wishes to distribute in networks. That’s it! One check box vs entering in the subnet. 2. customer had two edge devices and wished them to have a link over the innerwebs' to connect via OSPF in the event of a network break it would allow traffic to come in one peer and then traverse across the net to the other OSPF router without issues. In this case when he tried to bring up a GRE or any such tunnel using the provider /30s it would go across his network, not good and cause issues. Just a few, but 99% of the time there is something or some way better to do it, I have turned off distribute connected many times but have yet to turn it on. PPPoE the proper method is to have a stub area and filter it out. Especially if you have two or more PPPoE servers at each tower site. Dennis Burgess, Mikrotik Certified Trainer MTCNA, MTCRE, MTCWE, MTCTCE, MTCINE, MTCSE, HE IPv6 Sage, Cambium ePMP Certified Author of "Learn RouterOS- Second Edition” Link Technologies, Inc -- Mikrotik & WISP Support Services Office: 314-735-0270 Website: http://www.linktechs.net Create Wireless Coverage’s with www.towercoverage.com -----Original Message----- From: AF <af-boun...@af.afmug.com> On Behalf Of Ken Hohhof Sent: Thursday, January 2, 2020 4:57 PM To: 'AnimalFarm Microwave Users Group' <af@af.afmug.com> Subject: Re: [AFMUG] PPPoE and /32's The only reason I can think of, is that you have to be careful if you assign an IP address like 192.168.88.1 or 169.254.1.x to an interface for maybe administrative purposes, if that interface ever becomes active, and you don't have a route filter, then the router will advertise that block via OSPF. Can you be more specific why it is bad bad bad? I have actually been known to redistribute static routes (usually with a filter). I'm guessing you would characterize that as 4 or 5 bads? Usually this is to route a small block to a microPOP or customer router that I don't want to be an OSPF peer. In some cases the customer router is connected via PPPoE. I made the mistake once of trying to mix PPPoE and OSPF on an interface. That was indeed very bad. Oh, and I hope you realize some people like doing bad things, dangerous things, forbidden things. Like if a girl wants a guy to ask her out, she will get a friend to tell him she's off limits, which will make her irresistible. But then: https://tvtropes.org/pmwiki/pmwiki.php/Main/MySisterIsOffLimits -----Original Message----- From: AF <af-boun...@af.afmug.com> On Behalf Of Dennis Burgess via AF Sent: Thursday, January 2, 2020 3:16 PM To: AnimalFarm Microwave Users Group <af@af.afmug.com> Cc: Dennis Burgess <dmburg...@linktechs.net> Subject: Re: [AFMUG] PPPoE and /32's NEVER redistribute connected... bad bad bad . The sub area you can announce out the /25 or whatever it is, but keep /32s from leaving the stub area. Your OSPF-out filters do not work inner area, i.e. between backbone and backbone routers, only intra-area, that means area 44 (stub) it will filter out the /32s.. Dennis Burgess, Mikrotik Certified Trainer MTCNA, MTCRE, MTCWE, MTCTCE, MTCINE, MTCSE, HE IPv6 Sage, Cambium ePMP Certified Author of "Learn RouterOS- Second Edition” Link Technologies, Inc -- Mikrotik & WISP Support Services Office: 314-735-0270 Website: http://www.linktechs.net Create Wireless Coverage’s with www.towercoverage.com -----Original Message----- From: AF <af-boun...@af.afmug.com> On Behalf Of Adam Moffett Sent: Thursday, January 2, 2020 12:10 PM To: af@af.afmug.com Subject: [AFMUG] PPPoE and /32's If you redistribute connected routes on a PPPoE server you get a route for every /32 and that's undesirable. My solution currently is to NOT redistribute connected and instead just advertise the larger network which will encompass all the /32's. I read a presentation suggesting to use an OSPF stub area for the PPPoE concentrator. Is there a reason I'd want to use a stub area instead of specifying the network to distribute? -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
