Direct protocol affects BGP

Fabiano D'Agostino fabiano.dagostino96 at gmail.com
Wed Mar 25 17:40:33 CET 2020


ah okay thanks, I understand now!

Il giorno mer 25 mar 2020 alle ore 17:33 Alexander Zubkov <green at qrator.net>
ha scritto:

> Than I see no problem. When you have direct protocol off - your router
> have nothing imported to the bird's routing table and so nothing is
> exported to the bgp peer. A kernel protocol does not import those
> routes, from the documentation:
>
> > Note that routes created by OS kernel itself, namely direct routes
> representing IP subnets of associated interfaces, are not imported even
> with learn enabled. You can use Direct protocol to generate these direct
> routes.
>
> On Wed, Mar 25, 2020 at 5:21 PM Fabiano D'Agostino
> <fabiano.dagostino96 at gmail.com> wrote:
> >
> > Yes, I disabled direct protocol on both routers. The full bird.conf is
> the following:
> > log syslog all;
> > ipv4 table master4;
> > ipv6 table master6;
> > router1 bgp configuration:
> > protocol bgp {
> >     ipv4 {
> >             import all;
> >             export all;
> >    };
> >    local as 1;
> >    neighbor 192.168.2.22 as 2;
> > }
> > protocol device {
> > }
> > protocol kernel {
> >     ipv4 {
> >             table master4;
> >             import all;
> >             export all;
> >     };
> > }
> > protocol static {
> >     ipv4;
> > }
> >
> >
> > Il giorno mer 25 mar 2020 alle ore 17:06 Alexander Zubkov <
> green at qrator.net> ha scritto:
> >>
> >> Do you disable direct protocol on both router1 and router2?
> >> And that is definitely not the full bird config, you do not have a
> >> kernel protocol for example.
> >>
> >> On Tue, Mar 24, 2020 at 10:50 PM Fabiano D'Agostino
> >> <fabiano.dagostino96 at gmail.com> wrote:
> >> >
> >> > There is no gateway because they are directly connected. However my
> network topology is the following:
> >> > [pc-a - router1 ]=AS 1 ; [pc-b - router 2]=AS 2;
> >> > pc-a:
> >> > enp0s3
> >> > address 192.168.1.11
> >> > gw 192.168.1.1
> >> > router1:
> >> > enp0s3
> >> > address 192.168.1.1
> >> > enp0s8
> >> > 192.168.2.2
> >> >
> >> > router1 bgp configuration:
> >> > protocol bgp {
> >> >     ipv4 {
> >> >             import all;
> >> >             export all;
> >> >    }
> >> > local as 1;
> >> > neighbor 192.168.2.22 as 2
> >> >
> >> >
> >> > Il giorno mar 24 mar 2020 alle ore 22:40 Alexander Zubkov <
> green at qrator.net> ha scritto:
> >> >>
> >> >> There is also no gateway in you "route" output on routes exported
> from
> >> >> bird. Maybe you have some filters that causing it? Could you show
> your
> >> >> config if it is not secret?
> >> >>
> >> >> On Tue, Mar 24, 2020 at 9:53 PM Fabiano D'Agostino
> >> >> <fabiano.dagostino96 at gmail.com> wrote:
> >> >> >
> >> >> > Yes, 'show route', is from Bird. I don't have route-reflector, but
> just two routers which have a bgp session. Anyway, yes when direct is
> disabled, the bgp session is established.
> >> >> >
> >> >> > Il giorno mar 24 mar 2020 alle ore 21:45 Alexander Zubkov <
> green at qrator.net> ha scritto:
> >> >> >>
> >> >> >> "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
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://trubka.network.cz/pipermail/bird-users/attachments/20200325/717807cc/attachment.htm>


More information about the Bird-users mailing list