[j-nsp] AS path preservation when importing from instance.inet.0 to inet.0

[Paul S.]

Hi Dragan,

That worked, actually. Many thanks!

As to the lt interface, will read up as suggested.

On 10/17/2016 03:18 AM, Dragan Jovicic wrote:
> You could try import-rib policy, where you match on bgp routes and 
> as-path prepend, something like this:
> set routing-options rib-groups rib-1 import-policy pl-1
> set policy-options policy-statement pl-1 term 10 from proto bgp
> set policy-options policy-statement pl-1 term 10 then as-path-prepend 
> "XXXX"
> set policy-options policy-statement pl-1 term 10 then accept
>
> Try and let me know please.
>
> [quote]
> Speaking of the lt tunnel, is there any clear drawbacks to using it? 
> Once upon a time, I recall hearing that it was bandwidth constrained. 
> I'm doing this on a Trio MX.
> [/quote]
>
> There is a bandwidth limitation, check out docs. As for when to use 
> it, depends...
>
> Best
>
> Dragan
>
>
>
> On Sun, Oct 16, 2016 at 6:05 PM, Paul S. <contact at winterei.se 
> <mailto:contact at winterei.se>> wrote:
>
>     Hi guys,
>
>     So, in a bit of a peculiar situation. I think rather than
>     explaining it, it's possibly easier to express through configs.
>     I've added it at the end of the email.
>
>     Basically, my local-as in a ri is different compared to my
>     local-as set in the master instance. When I import a BGP route
>     (that I'm actually originating in the RI and would like to
>     originate in the master instance too), and then export it to other
>     peers -- the originating ASN gets rewritten to the master
>     instance's ASN instead.
>
>     For example - AS-path in RI A for 20.20.20.0/24
>     <http://20.20.20.0/24> is [2] I
>
>     When imported via instance-import to inet.0 and exported to other
>     peers, I can see that the AS-path becomes [1] I. What I'd like it
>     to be is [1 2] I, i.e: the RI looks like a downstream adjacency of
>     the master instance instead.
>
>     Is there any way to achieve this (other than setting up a lt
>     tunnel and peering with the master)? Speaking of the lt tunnel, is
>     there any clear drawbacks to using it? Once upon a time, I recall
>     hearing that it was bandwidth constrained. I'm doing this on a
>     Trio MX.
>
>     Pointers welcome, thank you for reading.
>
>     (As to why the multi-asn stupidity, that's due to a limitation on
>     our upstream provider's side. Sadly, no control over that)
>
>
>     Config from the "*master*" instance:
>
>
>     routing-options {
>
>         router-id 1.1.1.1;
>
>        autonomous-system 1;
>
>     }
>
>     protocols
>
>     {
>
>         bgp {
>
>            nei 10.10.10.10 peer-as 500;
>
>        }
>
>     }
>
>
>     Config from a *second* routing-instance
>
>     A {
>
>         instance-type virtual-router;
>
>         interface x;
>
>         routing-options {
>
>             router-id 2.2.2.2;
>
>         }
>
>         protocols { bgp {
>
>             nei 10.10.10.15 peer-as 500;
>
>             nei 10.10.10.15 local-as *2;*
>
>          }
>
>     }
>
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