Direct protocol affects BGP

[Alexander Zubkov]

"show route" looks a little weird, is it from bird? There are also
commonly a protocol and metric shown.
Those are from your route-reflector? Do you have your bgp sessions up
when direct is disabled?

On Tue, Mar 24, 2020 at 9:33 PM Fabiano D'Agostino
<fabiano.dagostino96 at gmail.com> wrote:
>
> Good evening Alexander,
>
> Direct protocol enabled:
> 'route' command:
> Destination Gateway Genmask            Flags Metric iface
> 192.168.1.0      *        255.255.255.0       U       0         enp0s3
> 192.168.1.0      *        255.255.255.0       U       32       enp0s3
> 192.168.2.0      *        255.255.255.0       U       0         enp0s8
> 192.168.2.0      *        255.255.255.0       U        32      enp0s8
> 192.168.4.0      *        255.255.255.0       U        32      enp0s8
> 'show route' command:
> 192.168.1.0/24 enp0s3
> 192.168.2.0/24  enp0s8 via 192.168.2.22 on enp0s8
> 192.168.4.0/24 via 192.168.2.22 on enp0s8
>
> Direct protocol disabled:
> 'route' command:
> Destination Gateway Genmask            Flags Metric iface
> 192.168.1.0      *        255.255.255.0       U       0         enp0s3
> 192.168.2.0      *        255.255.255.0       U       0         enp0s8
> 'show route' command:
> empty
>
> Thanks,
>
> Fabiano
>
> Il giorno mar 24 mar 2020 alle ore 21:00 Alexander Zubkov <green at qrator.net> ha scritto:
>>
>> I think it would be easier if you showed your route tables in both cases.
>>
>> On Tue, Mar 24, 2020 at 8:57 AM Irene Lalioti <irene.lalioti at restena.lu> wrote:
>> >
>> > Hello guys!
>> >
>> > Just because today we encountered again the same issue with direct, I am very curious on this:
>> >
>> > I totally agree with what you guys explained about the need of the direct protocol. Once we set it then reachability works and all is ok.
>> >
>> > Our big question is why was it working before the moment it lost the BGP session?? In other words: the set up :
>> >
>> > RS - BGP session with the ROUTER - and behind the Router we have Caches.
>> >
>> > Before the router was announcing to the RS(BIRD v2.0.7) the caches and that they are reachable by the router. Without any direct.
>> >
>> > Until one day we lose the bgp session, and we can ping the caches from the RS but not reachable . Once we set it as direct on the bird then all is fine.
>> >
>> > Question is why was it working before without direct ?? :=)
>> >
>> > Many thanks for your time!
>> >
>> > Have a great day all!
>> >
>> > Irene.
>> >
>> > On 23/03/2020 17:07, Fabiano D'Agostino wrote:
>> >
>> > Hi Bernd,
>> > no, the routing "from the kernel" doesn't come via 'learn yes', but via RIB, I mean if I do 'route' it shows the directly connected networks. The problem is that if I use the Direct protocol, the command 'route' shows me two same directly connected networks, one coming from RIB and the other one coming from Bird.
>> > I tried protocol bgp { direct; }, but it doesn't change.
>> >
>> > Thanks,
>> >
>> > Fabiano
>> >
>> > Il giorno lun 23 mar 2020 alle ore 16:15 Bernd Naumann <bena at spreadshirt.net> ha scritto:
>> >>
>> >> On 23.03.20 16:01, Fabiano D'Agostino wrote:
>> >> > Hi Benedikt,
>> >> > I am just learning Bird and I didn't want to use the Direct protocol
>> >> > because using it I have two same routes in the RIB for the directly
>> >> > connected networks, one coming from the kernel and the second one coming
>> >> > from the direct protocol.
>> >>
>> >>
>> >> Is the routing "from the kernel" coming via `learn yes;`? If you have no
>> >> need to import "alien" routes, you can disable `learn` and just use
>> >> `direct` and `static` protocol. /* OR if you know that your neighbor is
>> >> directly connected to you can also set 'direct' on the `protocol bgp`. */
>> >>
>> >> Bernd
>> >>
>> >>
>> >
>> > --
>> > Irene Lalioti
>> > Network Engineer
>> > Fondation RESTENA
>> > 2, avenue de l'Université
>> > L-4365 Esch/Alzette
>> >
>> > Tel: +352 424409 1
>> > Fax: +352 422473