On Thu, Jan 2, 2025 at 3:24 PM Tom Beecher <beec...@beecher.cc> wrote:
>
> I'm not saying I *would* do it, or you *should* do it, I'm just answering the
> questions being asked. :)
>
oh! fair enough... "that is a ton of complexity" still applies, or at
least for my view that's more complexity than: "always I announce to
all, with some metrics to make me seem there but just farther away on
link X"
> On Thu, Jan 2, 2025 at 3:21 PM Christopher Morrow <morrowc.li...@gmail.com>
> wrote:
>>
>> On Thu, Jan 2, 2025 at 2:55 PM Tom Beecher <beec...@beecher.cc> wrote:
>> >
>> > Jean-
>> >
>> > Thanks. Many BGP implementations have the ability to do conditional
>> > advertisements, where you announce (or don't) a set of prefixes based on
>> > the presents (or absence) of other routes. I don't think quagga does
>> > natively, and not sure if VyOS has added that on.
>> >
>> > Conceptually, you want to be doing "announce these prefixes from this
>> > router only if I don't see routes from the upstream on the other router".
>> > The 'safest' way is probably to just monitor default, but it depends on
>> > your environment.
>> >
>>
>> That sort of thing seems like extra complexity, no?
>> If the 2 internal routers have iBGP and you are fairly sure that you
>> won't lose that path/view you should be able to just announce
>> the same prefixes to both ISP peerings and possibly add some
>> metric-equivalent data to distance one link vs the other, no?
>> (common metric for this is the as-path, add your as N times, where N
>> is <10 and > 2 probably?)
>>
>> how exact do you want your split here to be jfranco ? (is 'mostly
>> everything over PRIMARY with some over SECONDARY' ok?)
>>
>> > On Fri, Dec 27, 2024 at 6:09 PM Jean Franco <jfra...@maila.inf.br> wrote:
>> >>
>> >> Hi Tom,
>> >> This is exactly what I was planning.
>> >> I'm announcing a block via ISP1 and another set of blocks via ISP2, and
>> >> have iBGP running between them.
>> >>
>> >> Thanks a lot!!
>> >>
>> >> Best regards,
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >> On Fri, Dec 27, 2024 at 1:00 PM Tom Beecher <beec...@beecher.cc> wrote:
>> >>>
>> >>> Jean-
>> >>>
>> >>> Yeah, don't worry about people complaining.
>> >>>
>> >>> Is this an accurate description of what you are trying to achieve?
>> >>>
>> >>> - Have 2 different sets of prefixes that you announce. Set A via
>> >>> router1/ISP1 , Set B via router2/ISP2
>> >>> - If BGP to one of your ISPs goes down, start announcing those prefixes
>> >>> to the other ISP. ( Example, if ISP2 goes down, start announcing prefix
>> >>> Set B over ISP1 )
>> >>>
>> >>> On Thu, Dec 26, 2024 at 8:16 AM Jean Franco <jfra...@maila.inf.br> wrote:
>> >>>>
>> >>>> Hi guys,
>> >>>> I've been on the list for as long as I cannot even remember.
>> >>>> So just you know, I'm not new at this.
>> >>>>
>> >>>> This is no easy task, that's why I came here looking for help.
>> >>>> I'm sorry if I brought anguish to the experts on the list!
>> >>>> I thought I could bring something that someone may have experienced
>> >>>> before.
>> >>>>
>> >>>> I haven't solved this yet, but at least I've received some valuable
>> >>>> suggestions and I Thank you!
>> >>>>
>> >>>> About all the details of the connections, numbers of peerings, PNI's
>> >>>> and IXP's I have left them out, since I figured this additional
>> >>>> information could make things worse.
>> >>>>
>> >>>> ISP 1 <router01> ====20KM====<Router>====20KM====<router02> ISP2
>> >>>>
>> >>>> The ISP connections are all 10G.
>> >>>> I don't believe these routers are DFZ capable.
>> >>>> All the routers are well capable and already receive the full routes.
>> >>>> The connections between these routers are 40G.
>> >>>>
>> >>>> Best regards,
>> >>>>
>> >>>>
>> >>>> On Thu, Dec 26, 2024 at 12:53 AM Bryan Fields <br...@bryanfields.net>
>> >>>> wrote:
>> >>>>>
>> >>>>> On 12/25/24 6:18 PM, Randy Bush wrote:
>> >>>>> > where does one go for is-is help? the mtu issie can be painful!!!
>> >>>>>
>> >>>>> I think here would be good too. I recently had to do this between a
>> >>>>> Cisco
>> >>>>> 3945e and a Juniper, and from my unrevised notes:
>> >>>>>
>> >>>>> vlan {
>> >>>>> unit 405 {
>> >>>>> family iso {
>> >>>>> # holy shit this is important. CISCO and Juniper will not talk
>> >>>>> unless the
>> >>>>> MTU is set
>> >>>>> mtu 1492;
>> >>>>> }
>> >>>>> }
>> >>>>> }
>> >>>>>
>> >>>>> :-)
>> >>>>>
>> >>>>> --
>> >>>>> Bryan Fields
>> >>>>>
>> >>>>> 727-409-1194 - Voice
>> >>>>> http://bryanfields.net
