Subject: [Idr] draft-chen-bgp-redist-01.txt

From: Enke Chen <[email-masked]>
Date: Tue, 29 Jun 2021 10:13:32 -0700

Hi, Folks:

Apologies for the very long delay in updating the draft:

       https://datatracker.ietf.org/doc/draft-chen-bgp-redist/01/

The issue still exists, and shows up from time to time. The revised version
provides a complete solution that covers the use cases involving a single
router as well as multiple routers in a network.

Your review and comments are welcome.

Thanks.   -- Enke

---

From: Robert Raszuk <[email-masked]>
Date: Tue, 29 Jun 2021 22:05:43 +0200

Hi Enke,

How do you assure that admin distance is the same or delta would be the
same across implementations ?

Looking at say junos I see quite different values then when comparing with
other implementations ...

https://www.juniper.net/documentation/en_US/junos/topics/reference/general/routing-protocols-default-route-preference-values.html

Would it be simpler to define here verbatim what the local pref should be
for redistributed routes ? Then at least those could be used as default
local pref values unless overwritten by operator's policy during
redistribution.

Thx,
Robert

On Tue, Jun 29, 2021 at 7:14 PM Enke Chen <[email-masked]>
wrote:

> The issue still exists, and shows up from time to time. The revised
> version provides a complete solution that covers the use cases involving a
> single router as well as multiple routers in a network.
>
> _______________________________________________
> Idr mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/idr
>

---

From: Enke Chen <[email-masked]>
Date: Wed, 30 Jun 2021 00:19:02 -0700

Hi, Robert:

1) Usually the default admin-distance is configurable. Having the same
admin-distance across implementations would certainly make things simpler,
but that is not required. What matters is the local_pref value for the
redistribute backup route:

            local_pref = default_local_pref - delta;

It needs to be in the right order (relatively) for the "role" the route is
supposed to play.

It's a good question. We will try to clarify it in the next revision.

2) Certainly it would work if we define the "delta" (or "local_pref") for
the redistributed route based on its role (e.g., primary, secondary,
tertiary). But extra config would be needed for specifying the "role".  The
algorithm described in the draft does not require additional config other
than the existing "admin-distance".  When more than two paths are involved
in a multi-vendor environment, the admin-distance needs to be carefully
assigned in order to get the desired local_pref value.

Thanks.   -- Enke

On Tue, Jun 29, 2021 at 1:05 PM Robert Raszuk <[email-masked]> wrote:

> <https://urldefense.proofpoint.com/v2/url?u=https-3A__www.juniper.net_documentation_en-5FUS_junos_topics_reference_general_routing-2Dprotocols-2Ddefault-2Droute-2Dpreference-2Dvalues.html&d=DwMFaQ&c=V9IgWpI5PvzTw83UyHGVSoW3Uc1MFWe5J8PTfkrzVSo&r=OPLTTSu-451-QhDoSINhI2xYdwiMmfF5A2l8luvN11E&m=iUboWFiSpP9QvSDj9hoG8_DO7R_8EOQvfEHnwyX-mc0&s=GOhXjwEf1z0GAfIQVgVAc4sHvcAog6czTO30VhKwzQk&e=>
>
>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__datatracker.ietf.org_doc_draft-2Dchen-2Dbgp-2Dredist_01_&d=DwMFaQ&c=V9IgWpI5PvzTw83UyHGVSoW3Uc1MFWe5J8PTfkrzVSo&r=OPLTTSu-451-QhDoSINhI2xYdwiMmfF5A2l8luvN11E&m=iUboWFiSpP9QvSDj9hoG8_DO7R_8EOQvfEHnwyX-mc0&s=IBn3kTJmGrWISvSq8L3M9GLLamXIqw7t2PvEdtvhmos&e=>
>>
>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__www.ietf.org_mailman_listinfo_idr&d=DwMFaQ&c=V9IgWpI5PvzTw83UyHGVSoW3Uc1MFWe5J8PTfkrzVSo&r=OPLTTSu-451-QhDoSINhI2xYdwiMmfF5A2l8luvN11E&m=iUboWFiSpP9QvSDj9hoG8_DO7R_8EOQvfEHnwyX-mc0&s=O1wpTf7XmDmE4-mQGDJ9YNEx2UVZW-k1meY3fd-tQrE&e=>
>>
>