I'm not saying I *would* do it, or you *should* do it, I'm just answering
the questions being asked. :)
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
>
