Hi Jorge,
In our discussion in another thread, we discussed two types ot the use cases of
draft-ietf-bess-evpn-prefix-advertisement,
They are the GW-IP as overlay index use cases (just let me call them
GW-IP-Style use-cases for short) and the Bump-in-the-wire use case.
I think it is better to discuss it more clearly in a new thread.
1) For the GW-IP-Style use cases, thank you for telling me that the following
text may be contradictory (But I don't think it is like that, I will explain it
later) with my approach :
". If the RT-5 specifies a GW IP address as the Overlay Index,
recursive resolution can only be done if the NVE has received and
installed an RT-2 (MAC/IP route) specifying that IP address in
the IP address field of its NLRI."
It seems that we have to find out that RT-2 before the recursive
resolution.
I just don't know that how can we know there is such a RT-2 before the
recursive resolution ?
We should note that the keys of that RT-2 is <RD, IP, MAC>, but the GW-IP
is just an IP.
So how can we find out that RT-2 just using an IP before the recursive
resolution?
2) For the ESI as overlay index use cases, there is similar text as the
following:
". If the RT-5 specifies an ESI as the Overlay Index, recursive
resolution can only be done if the NVE has received and
installed
an RT-1 (Auto-Discovery per-EVI) route specifying that ESI."
Given that the keys of RT-1 are <RD, ESI, Ethernet Tag ID>,
So how can we find out that RT-2 before recursive resolution just using <ESI,
Ethernet Tag ID> ?
3) For Bump-in-the-wire use case, we would find many RT-1 routes for that ESI
even after the recursive rosolution.
Just take the Figure 7 of [IP Prefix Advertisement] for example,
How can DGW1 in that Figure find out the exact RT-1 of <ESI23, BD-10> ?
We should note that the RDs of BDs are different from the RD of that IP-VRF.
To be clear, If the DGW1 receives a RT-5 route R5 (IPL=24, IP=SN1,
ESI=ESI23, from NVE2) and two RT1 routes R1_BD1<RD=BD-10, ESI23, 0> and
R1_BD2<RD=BD-20, ESI23, 0>.
These two RT1 routes both can be imported into the same IP-VRF instance.
Which RT-1 route will R5's ESI overlay index be resolved to?
The R1_BD1 or the R1_BD2 ?
4) For Bump-in-the-wire use case, Both of NVE2 and NVE3 will advertise a RT-5
route to DGW1,
Will the common ESI23 of these two RT-5 routes be resolved to the same
RT-1 route? and how?
Note that even the RD of BD-10 will be different on NVE2 and NVE3.
When they are the same RD,I think there wil be method that the RT-5 from
NVE3 can be resolved to the same RT-1 from NVE2.
5) For Bump-in-the-wire use case, If NVE3 advertise another RT-5 route R5b for
another BD (say BD-20) but for the another prefix (e.g. SN2) of the same IP-VRF.
If the RD of that R5b is the same as R5 (see question 3), will the ESI23
of R5b be resolved to the same RT-1 as what R5 will be resolved to?
It seems that they will, according current procedures. But is this result
in expectation ?
Note that ESI23 is provisioned on attachment ports, but both BD-10 and
BD-20 can have an separate AC on the same port.
Regards,
Yubao_______________________________________________
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