FWIW this is what I'm doing. I have a bigger pipe that gets /22 and /22 where the smaller pipe gets /23
Josh Luthman Office: 937-552-2340 Direct: 937-552-2343 1100 Wayne St Suite 1337 Troy, OH 45373 On Wed, Nov 1, 2017 at 2:53 PM, Shawn C. Peppers via Mikrotik-users < mikrotik-users@wispa.org> wrote: > Yes. > Example... > If you have a /22 total > > A > /24 > /22 > > C > /22 > > S > /24 > /22 > > In this event all routers would announce your whole /22 ip block. > > But...A and S would be announcing out smaller more specific ip blocks of > the /22 making the specific /24 traffic to follow that specific router. > > In the event something failed traffic would follow one of the other > routers. > > If you need your failover traffic to be more controlled you would have to > use bgp filters to prepend and weight. > > > > Shawn C. Peppers > Video Direct > 866-680-8433 Toll Free > http://www.video-direct.tv > > > On Nov 1, 2017, at 1:44 PM, Ethan E. Dee via Mikrotik-users < > mikrotik-users@wispa.org> wrote: > > > > If I advertise a summarized subnet to C and more specific subnets to A > > and S, would C only failover in event of losing A or S? > > > > > >> On 11/1/2017 10:45 AM, Faisal Imtiaz wrote: > >> Feel free to call me.. > >> > >> 305 921 4141 > >> > >> > >> Faisal Imtiaz > >> Snappy Internet & Telecom > >> http://www.snappytelecom.net > >> > >> Tel: 305 663 5518 x 232 > >> > >> Help-desk: (305)663-5518 Option 2 or Email: supp...@snappytelecom.net > >> > >> ----- Original Message ----- > >>> From: "Ethan E. Dee" <e...@globalvision.net> > >>> To: "Faisal Imtiaz" <fai...@snappytelecom.net> > >>> Cc: "Mikrotik Users" <mikrotik-users@wispa.org> > >>> Sent: Wednesday, November 1, 2017 10:31:41 AM > >>> Subject: Re: [Mikrotik Users] BGP Question > >>> I'm confused as to why I need iBGP in order to maintain traffic outside > >>> of my network. Is iBGP able to make changes to my eBGP peering sessions > >>> that would be helpful to my cause? Or are you just saying I should be > >>> running iBGP internally to make things less messy in general? > >>> > >>> It is possible it is going over my head. Would you be able call me and > >>> explain? > >>> > >>>> On 11/1/2017 10:09 AM, Faisal Imtiaz wrote: > >>>> See answers inline .. > >>>> > >>>> Faisal Imtiaz > >>>> Snappy Internet & Telecom > >>>> http://www.snappytelecom.net > >>>> > >>>> Tel: 305 663 5518 x 232 > >>>> > >>>> Help-desk: (305)663-5518 Option 2 or Email: supp...@snappytelecom.net > >>>> > >>>> ----- Original Message ----- > >>>>> From: "Ethan E. Dee" <e...@globalvision.net> > >>>>> To: "Faisal Imtiaz" <fai...@snappytelecom.net>, "Mikrotik Users" > >>>>> <mikrotik-users@wispa.org> > >>>>> Sent: Wednesday, November 1, 2017 9:51:56 AM > >>>>> Subject: Re: [Mikrotik Users] BGP Question > >>>>> I am only referring to traffic leaving the internet and entering my > network. > >>>> This is called inbound traffic... yes that is exactly what I was > talking about > >>>> too. > >>>>> I do not want A's traffic to come in thru C unless it is absolutely > >>>>> dire. i.e. the BGP session on A quits or the router itself dies. > >>>>> > >>>> I understand, what you desire to do.. however it may not match up to > what your > >>>> Upstream Desires.. > >>>> (e.g. if you advertise A's prefix as 'normal' and C's prefix as > 'backup'... A's > >>>> network will see C as local connected and insist on using it over an > external > >>>> route) > >>>> > >>>> > >>>> > >>>>> I have tried setting BGP prepend to 16x on C. > >>>> Like I said, that will not work for you... > >>>> > >>>>> I have used At&t and Charter Communities to announce a different > local > >>>>> pref (100 on At&t 70 on Charter.) > >>>>> > >>>> Sort of right track, but you have to evaluate as to how they have > their network > >>>> configured. > >>>> Keep in mind Local Pref is only Local to that ASN.. you have to look > at their > >>>> network traffic engineering to determine if you are making yourself > more > >>>> attractive or less attractive ... and use the local pref figures > comparative to > >>>> their's.... i.e. local pref of 70 does not mean the same thing on all > networks > >>>> ! (it is a relative parameter) > >>>> > >>>>> No luck. Looking at the looking glass, Charter is largely the > preferred > >>>>> path for HE. See attached. > >>>> Welcome to solving a 3 dimensional equation... Charter may be > Purchasing IP > >>>> Transit from HE or peering with HE.... > >>>> Which would explain this.. > >>>> > >>>>> Get a similar answer from Cogent's looking glass. > >>>> Not sure if you are reading the 'details' as some of the LG's show.. > or just the > >>>> 'best path' along with ASN's > >>>>> I am using OSPF as my IGP btw. I can route the traffic out the > correct > >>>>> router just fine. It is the returning traffic I have a problem with. > >>>>> > >>>> This is not the proper way to do things... > >>>> The recommended best practices are :- > >>>> > >>>> use OSPF for distributing loop back IP's > >>>> use iBGP (a requirement) between all the routers (each router needs > one session > >>>> to each of the others) for re-distributing your BGP routes > >>>> > >>>> If you want to run your network as three islands, I suppose you could > do it they > >>>> way you are trying to.. > >>>> but you are going to have some interesting issues to deal with > (especially if > >>>> there is an anomaly on one of the paths, and your asymmetric traffic > will show > >>>> weird stuff). > >>>> > >>>>> Do not be afraid to assume I have no idea what I am doing. I have > >>>>> followed every rule I can find online so obviously I'm doing > something > >>>>> wrong. > >>>>> > >>>>> > >>>>> > >>>>>> On 11/1/2017 9:45 AM, Faisal Imtiaz wrote: > >>>>>> I wish there was a simple answer to your question... > >>>>>> > >>>>>> But... there are some more questions.... > >>>>>> > >>>>>> With the setup you have described..... > >>>>>> Are you running iBGP sessions between all the routers ? > >>>>>> if not.. then you are not properly configured. > >>>>>> > >>>>>> In today's day and age, one needs to do Traffic Engineering to have > the type of > >>>>>> traffic flow one desires. > >>>>>> I wish there was a 'one solution' that fits all situations.. > but there isn't > >>>>>> one. > >>>>>> Each IP Transit provider is doing their own 'style' of Network > Traffic > >>>>>> Engineering > >>>>>> One has to understand that first and then try to compensate > for it. > >>>>>> One should ask their upstream for a list of their BGP > Communities, that gives a > >>>>>> good starting point. > >>>>>> Using the upstream's Looking glass, if available is also a > great tool in > >>>>>> verifying the traffic engineering > >>>>>> > >>>>>> simply passing ASN's does not work (most of the time, but varies > with upstream) > >>>>>> > >>>>>> BGP Traffic engineering is more like steering a Boat Rudder than > steering a > >>>>>> car... :) > >>>>>> > >>>>>> If what is listed above makes sense to you, then you have some > starting points > >>>>>> to read up and understand BGP > >>>>>> If the above does not.. then I suggest you get someone to help you > with the > >>>>>> setup. > >>>>>> > >>>>>> Regards. > >>>>>> > >>>>>> Faisal Imtiaz > >>>>>> Snappy Internet & Telecom > >>>>>> http://www.snappytelecom.net > >>>>>> > >>>>>> Tel: 305 663 5518 x 232 > >>>>>> > >>>>>> Help-desk: (305)663-5518 Option 2 or Email: > supp...@snappytelecom.net > >>>>>> > >>>>>> ----- Original Message ----- > >>>>>>> From: "Ethan E. Dee via Mikrotik-users" <mikrotik-users@wispa.org> > >>>>>>> To: "Mark Grigsby via Mikrotik-users" <mikrotik-users@wispa.org> > >>>>>>> Sent: Wednesday, November 1, 2017 9:06:27 AM > >>>>>>> Subject: [Mikrotik Users] BGP Question > >>>>>>> I am multihomed. I have a router that peers with charter and > advertises > >>>>>>> a few subnets. (Let's call it C) > >>>>>>> > >>>>>>> I have a router that peers with AT&T at a tower (lets call it A) > >>>>>>> > >>>>>>> And a router that peers with Spirit at a tower (lets call it S) > >>>>>>> > >>>>>>> AT&T seems to have quite a low preference to the world. And I have > no > >>>>>>> idea what I'm doing. Though I feel like I do. > >>>>>>> > >>>>>>> Nothing works. > >>>>>>> > >>>>>>> All three routers are mikrotik. How do I tell the world to forget > about > >>>>>>> Charters advertisements unless you can no longer see AT&T? > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>> -- > >>>>>>> This message has been scanned by E.F.A. Project and is believed to > be clean. > >>>>>>> > >>>>>>> > >>>>>>> _______________________________________________ > >>>>>>> Mikrotik-users mailing list > >>>>>>> Mikrotik-users@wispa.org > >>>>>>> http://lists.wispa.org/mailman/listinfo/mikrotik-users > > > > _______________________________________________ > > Mikrotik-users mailing list > > Mikrotik-users@wispa.org > > http://lists.wispa.org/mailman/listinfo/mikrotik-users > _______________________________________________ > Mikrotik-users mailing list > Mikrotik-users@wispa.org > http://lists.wispa.org/mailman/listinfo/mikrotik-users >
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