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
