Hi Jorge,
> +----------+----------+----------+------------+----------------+
> | ESI | GW-IP | MAC* | Label | Overlay Index |
> |--------------------------------------------------------------|
> | Non-Zero | Zero | Zero | Don't Care | ESI |
> | Non-Zero | Zero | Non-Zero | Don't Care | ESI |
> | Zero | Non-Zero | Zero | Don't Care | GW-IP |
> | Zero | Zero | Non-Zero | Zero | MAC |
> | Zero | Zero | Non-Zero | Non-Zero | MAC or None** |
> | Zero | Zero | Zero | Non-Zero | None(IP NVO)***|
> +----------+----------+----------+------------+----------------+
>
> The fifth row is like a variation of the fourth row; why isn't there a
> corresponding variation for each of the first three rows? The following
> paragraph mentioned earlier seems to apply to all situations.
> [JORGE] in rows 4 and 5, the label value 0 or non-0 has a meaning. In the
> first
> three rows, the label doesn’t have any meaning.
Can you elaborate on "the label does not have any meaning", especially for row
#2?
>
> I struggled with the "IP NVO" in the sixth row because clearly this is
> MPLS
> tunnel not IP tunnel. Then I realized that "IP" here refers to the payload not
> the tunnel type:
>
> IP NVO tunnel: it refers to Network Virtualization Overlay tunnels
> with IP payload (no MAC header in the payload).
>
> I have to say that "IP NVO tunnel" is a little misleading.
> [JORGE] well, that’s why we put it in the terminology in section 1. Let me
> know if you think the description requires clarification. I’ll leave it as it
> is for
> the time being.
For the particular confusion that I had with the sixth row, we could probably
just remove "IP NVO". You have a *** note for it anyway.
>
>
> In section 4.1:
>
> o Based on the MAC-VRF10 route-target in DGW1 and DGW2, the IP
> Prefix route is also imported and SN1/24 is added to the IP-
> VRF with Overlay Index IP2 pointing at the local MAC-VRF10. We
> assume the RT-5 from NVE2 is preferred over the RT-5 from
> NVE3. Should ECMP be enabled in the IP-VRF and both routes
> equally preferable, SN1/24 would also be added to the routing
> table with Overlay Index IP3.
>
> The last two sentences seem to be contradicting. One says "preferred over"
> and the other says "equally preferable".
> [JORGE] ok, I clarified it with this sentence:
> “In this example, we assume the RT-5 from NVE2 is preferred over the RT-5
> from NVE3. If both routes were equally preferable and ECMP enabled, SN1/24
> would also be added to the routing table with Overlay Index IP3.”
The original text is actually fine. I mis-read it.
>
> (5) When the packet arrives at NVE2:
> o Based on the tunnel information (VNI for the VXLAN case), the
> MAC-VRF10 context is identified for a MAC lookup.
> o Encapsulation is stripped-off and based on a MAC lookup
> (assuming MAC forwarding on the egress NVE), the packet is
> forwarded to TS2, where it will be properly routed.
>
> If the destination is actually on the TS3 side, how does TS2 send traffic
> to
> the final destination? Unless the topology is actually like the one in
> section 4.2
> traffic will get blackholed?
> [JORGE] yes the topology for SN1 is the same. But we wanted to add more
> subnets and hosts. I added: “We assume SN1/24 is dual-homed to NVE2 and
> NVE3.”
It would be nice the redraw the picture to indicate so. For example:
IP 4 ---+
SN 2 --+
| TS2
|--+
SN1 |
|--+
| TS3
SN 3 --+
IP 5 ---+
Jeffrey
_______________________________________________
BESS mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/bess
