[j-nsp] VRF export/import of eBGP learned route

[Philippe Girard]

Hi, thanks for adding to this.

I've just removed the loops statement in there to see what would happen. It
seems to me like the AS number in routing-options is pretty much the source
of the looping trigger that occurs (the addition of a second internal AS to
the path).

Everything works well and loop free without the loops statement, seems I
won't have to go the tunnel way.

Thanks again!

On Fri, Jun 29, 2018 at 5:39 PM Niall Donaghy <niall.donaghy at geant.org>
wrote:

> Hi Alexander,
>
> In our network, inet.0 is AS20965 and IAS.inet.0 is AS21320.
> The IAS routing instance contains all commercial routes - public, private,
> and upstream peerings.
>
> Between inet.0 and IAS.inet.0 we have logical tunnels with BGP peerings.
>
> The routers are all configured with autonomous-system 20965, but to
> networks
> external to AS21320, we appear as AS21320, with the following
> configuration:
>
> set routing-instances IAS protocols bgp group SOMEGROUP neighbor x.x.x.x
> local-as 21320
> set routing-instances IAS protocols bgp group SOMEGROUP neighbor x.x.x.x
> local-as private
> set routing-instances IAS protocols bgp group SOMEGROUP neighbor x.x.x.x
> local-as no-prepend-global-as
>
> This keeps things tidy, loop-free, and BGP all the way, ie: no RIB groups
> or
> 'loops 2' statements, and we benefit from BGP path loop detection, and BGP
> policy controls between the two ASes.
>
> We've been running with 2.6M routes this way for 2.5 years+ and no issues.
>
> Happy to share if ever you want to refine your solution.
>
> Br,
> Niall
>
> -----Original Message-----
> From: juniper-nsp [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf
> Of
> Philippe Girard
> Sent: 29 June 2018 15:15
> To: Alexander Arseniev <arseniev at btinternet.com>
> Cc: juniper-nsp at puck.nether.net
> Subject: Re: [j-nsp] VRF export/import of eBGP learned route
>
> Hello everyone
>
> Thank you so much for your suggestions. The solution in this case is to
> remove the autonomous-system statement completely from the routing-instance
> routing-options and apply the local-as statement under bgp with the private
> knob.
>
> protocols {
>     bgp {
>         local-as 456 loops 2 private
>
> This creates an internal table that looks just like it would under regular
> bgp inet.0.
>
> Thanks again!
>
> On Fri, Jun 29, 2018 at 4:07 AM Alexander Arseniev via juniper-nsp <
> juniper-nsp at puck.nether.net> wrote:
>
> > Hello,
> >
> > Does "no-prepend-global-as" help?
> >
> >
> > https://www.juniper.net/documentation/en_US/junos/topics/concept/bgp-l
> > ocal-as-introduction.html
> >
> > HTH
> >
> > Thx
> >
> > Alex
> >
> >
> > On 29/06/2018 04:58, Aaron Gould wrote:
> > > Use with caution in live environment as I'm going off of some
> > > testing I
> > was
> > > recently doing in my lab and I'm pretty sure I saw this same issue.
> > >
> > > Sounds like something I saw with my internet boundary pe's, would
> > > add my
> > AS
> > > on routes were learned from internet and send as vpnv4 routes into
> > > my internal ibgp environment and internal pe's were seeing their own
> > > AS and routes were being hidden as looped...
> > >
> > > Try this on PE1 ....
> > >
> > > If pe1 ebgp group is called "ebgp-to-ix"...
> > > If IX ip that you neighbor with is 1.2.3.4...
> > > If vrf on PE1 and PE2 is called "my-vrf"...
> > >
> > > ...do this on PE1...
> > > set routing-instances my-vrf protocols bgp group ebgp-to-ix neighbor
> > 1.2.3.4
> > > local-as private
> > >
> > > ...now see if PE2 is still seeing its own AS as looped
> > >
> > > - Aaron
> > >
> > >
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