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
