Eric,
In the discussion of inter-AS, I think the draft should discuss the
following issues:
- In order to use the segmented inter-AS procedures, each ASBR must be
pre-configured with the MVPNs whose trees pass through it. (See section
8.2.1.1 of draft-ietf-l3vpn-2547bis-mcast.)
Let's examine your claim that "in order to use the segmented inter-AS
procedures, each ASBR must be preconfigured with the MVPNs whose
trees pass through it".
Here are the relevant quotes:
From 8.2.1.1 of draft-ietf-l3vpn-2547bis-mcast-08.txt:
a. A Route Distinguisher for the MVPN. For a given MVPN each ASBR
in the AS must use the same RD when advertising this
information to other ASBRs. To accomplish this all the ASBRs
within that AS, that are configured to support the MVPN, MUST
be configured with the same RD for that MVPN. This RD MUST be
of Type 0, MUST embed the autonomous system number of the AS.
From 9.2.1 of draft-ietf-l3vpn-2547bis-mcast-bgp-07.txt:
+ The route carries a single MCAST-VPN NLRI with the RD set to the
RD configured for that MVPN on the ASBR, and the Source AS set to
the Autonomous System number of the ASBR.
From 9.2 of draft-ietf-l3vpn-2547bis-mcast-bgp-07.txt:
+ If the ASBR originates an Inter-AS I-PMSI A-D route for a
particular MVPN present on some of the PEs within its own AS, the
ASBR MUST be (auto-)configured with an RD for that MVPN. It is
RECOMMENDED that one of the following two options be used:
(1) To allow more aggregation of Inter-AS I-PMSI A-D routes it is
recommended that all the ASBRs within an AS that are configured
to originate an Inter-AS I-PMSI A-D route for a particular MVPN
be configured with the same RD (although for a given MVPN each AS
may assign this RD on its own, without coordination with other
ASes).
(2) To allow more control over spreading MVPN traffic among
multiple ASBRs within a given AS it is recommended for each ASBR
to have a distinct RD per each MVPN, in which case such an RD
SHOULD be auto-configured.
With all the above in mind it is clear that the only item that
involves configuration on ASBRs is the RD. With this in mind let's
look at the issue of configuring RDs on ASBRs.
From the above quotes it should be clear that section 8.2.1.1 of
draft-ietf-l3vpn-2547bis-mcast-08.txt that you referred to in your
e-mail is at best incomplete (and at worse incorrect), as it only
covers option (1) from 9.2 of draft-ietf-l3vpn-2547bis-mcast-bgp-07.txt,
but does *NOT* cover option (2). While option (1) does involve
configuring RDs, option (2) explicitly states that RDs "SHOULD be
auto-configured."
Thus, your claim above that "ASBR must be pre-configured with the
MVPNs whose trees pass through it" totally ignores the fact that
it applies only to one particular option (option (1) above). Your
claim is *incorrect* in the context of option (2). What is correct
though is that section 8.2.1.1 that you refers to is incomplete/incorrect.
Yakov.