Op 16-07-2021 om 05:54 schreef Hean Seng:
Hi Wido,

My initial thought is not like this,  it is the /48 at ISP router, and /64
subnet assign to AdvanceZoneVR,   AdvanceZoneVR responsible is
distribule IPv6 ip (from the assigned /64 sunet) to VM,  and not routing
the traffic,   in the VM that get the IPv6 IP will default route to ISP
router as gw.   It can may be a bridge over via Advancezone-VR.


How would you bridge this? That sounds like NAT?

IPv6 is meant to be routed. Not to be translated or bridged in any way.

The way a made the drawing is exactly how IPv6 should work in a VPC environment.

Traffic flows through the VR where it can do firewalling of the traffic.

However, If do as the way described in the drawing, then i suppose will be
another kind of virtual router going to introduce , to get hold the /48 in
this virtual router right ?


It can be the same VR. But keep in mind that IPv6 != IPv4.

The VR will get Frr as a new daemon which can talk BGP with the upper network to route traffic.

After this,  The Advance Zone, NAT's  VR will peer with this new IPv6 VR
for getting the IPv6 /64 prefix ?


IPv4 will be behind NAT, but IPv6 will not be behind NAT.

If do in this way, then I guess  you just only need Static route, with
peering ip both end  as one /48 can have a lot of /64 on it.  And hardware
budgeting for new IPv6-VR will become very important, as all traffic will
need to pass over it .


Routing or NAT is the same for the VR. You don't need a very beefy VR for this.

It will be like

ISP Router  ------ >  (new IPV6-VR ) ---- > AdvanceZone-VR ----> VM

Relationship of (new IPv6 VR) and AdvanceZone-VR , may be considering on
OSPF instead of  BGP , otherwise few thousand of AdvanceZone-VR wil have
few thousand of BGP session. on new-IPv6-VR

Also, I suppose we cannot do ISP router. -->. Advancezone VR direct,   ,
otherwise ISP router will be full of /64 prefix route either on BGP( Many
BGP Session) , or  Many Static route .   If few thousand account, ti will
be few thousand of BGP session with ISP router or few thousand static route
which  is not possible .






On Thu, Jul 15, 2021 at 10:47 PM Wido den Hollander <w...@widodh.nl> wrote:

But you still need routing. See the attached PNG (and draw.io XML).

You need to route the /48 subnet TO the VR which can then route it to
the Virtual Networks behind the VR.

There is no other way then routing with either BGP or a Static route.

Wido

Op 15-07-2021 om 12:39 schreef Hean Seng:
Or explain like this :

1) Cloudstack generate list of /64 subnet from /48 that Network admin
assigned to Cloudstack
2) Cloudsack allocated the subnet (that generated from step1) to Virtual
Router, one Virtual Router have one subniet /64
3) Virtual Router allocate single IPv6 (within the range of /64
allocated to VR)  to VM






On Thu, Jul 15, 2021 at 6:25 PM Hean Seng <heans...@gmail.com
<mailto:heans...@gmail.com>> wrote:

     Hi Wido,

     I think the /48 is at physical router as gateway , and subnet of /64
     at VR of Cloudstack.   Cloudstack only keep which /48 prefix and
     vlan information of this /48 to be later split the  /64. to VR.

     And the instances is getting singe IPv6 of /64  IP.   The VR is
     getting /64.  The default gateway shall goes to /48 of physical
     router ip .   In this case ,does not need any BGP router .


     Similar concept as IPv4 :

     /48 subnet of IPv6 is equivalent to current /24 subnet of IPv4 that
     created in Network.
     and /64  of IPv6 is equivalent to single IP of IPv4 assign to VM.




     On Thu, Jul 15, 2021 at 5:31 PM Wido den Hollander <w...@widodh.nl
     <mailto:w...@widodh.nl>> wrote:



         Op 14-07-2021 om 16:44 schreef Hean Seng:
          > Hi
          >
          > I replied in another thread, i think do not need implement
         BGP or OSPF,
          > that would be complicated .
          >
          > We only need assign  IPv6 's /64 prefix to Virtual Router
         (VR) in NAT
          > zone, and the VR responsible to deliver single IPv6 to VM via
         DHCP6.
          >
          > In VR, you need to have Default IPv6 route to  Physical
         Router's /48. IP
          > as IPv6 Gateway.  Thens should be done .
          >
          > Example :
          > Physical Router Interface
          >   IPv6 IP : 2000:aaaa::1/48
          >
          > Cloudstack  virtual router : 2000:aaaa:200:201::1/64 with
         default ipv6
          > route to router ip 2000:aaaa::1
          > and Clodustack Virtual router dhcp allocate IP to VM , and
         VM will have
          > default route to VR. IPv6 2000:aaaa:200:201::1
          >
          > So in cloudstack need to allow  user to enter ,  IPv6
         gwateway , and
          > the  /48 Ipv6 prefix , then it will self allocate the /64 ip
         to the VR ,
          > and maintain make sure not ovelap allocation
          >
          >

         But NAT is truly not the solution with IPv6. IPv6 is supposed to
be
         routable. In addition you should avoid DHCPv6 as much as
         possible as
         that's not really the intended use-case for address allocation
         with IPv6.

         In order to route an /48 IPv6 subnet to the VR you have a few
         possibilities:

         - Static route from the upperlying routers which are outside of
         CloudStack
         - BGP
         - OSPFv3 (broken in most cases!)
         - DHCPv6 Prefix Delegation

         BGP and/or Static routes are still the best bet here.

         So what you do is that you tell CloudStack that you will route
         2001:db8::/48 to the VR, the VR can then use that to split it up
         into
         multiple /64 subnets going towards the instances:

         - 2001:db8::/64
         - 2001:db8:1::/64
         - 2001:db8:2::/64
         ...
         - 2001:db8:f::/64

         And go on.

         In case of BGP you indeed have to tell the VR a few things:

         - It's own AS number
         - The peer's address(es)

         With FRR you can simply say:

         neighbor 2001:db8:4fa::179 remote-as external

         The /48 you need to have at the VR anyway in case of either a
         static
         route or BGP.

         We just need to add a NullRoute on the VR for that /48 so that
         traffic
         will not be routed to the upper gateway in case of the VR can't
         find a
         route.

         Wido

          >
          >
          >
          >
          >
          > On Wed, Jul 14, 2021 at 8:55 PM Alex Mattioli
          > <alex.matti...@shapeblue.com
         <mailto:alex.matti...@shapeblue.com>
         <mailto:alex.matti...@shapeblue.com
         <mailto:alex.matti...@shapeblue.com>>> wrote:
          >
          >     Hi Wido,
          >     That's pretty much in line with our thoughts, thanks for
         the input.
          >     I believe we agree on the following points then:
          >
          >     - FRR with BGP (no OSPF)
          >     - Route /48 (or/56) down to the VR
          >     - /64 per network
          >     - SLACC for IP addressing
          >
          >     I believe the next big question is then "on which level
         of ACS do we
          >     manage AS numbers?".  I see two options:
          >     1) Private AS number on a per-zone basis
          >     2) Root Admin assigned AS number on a domain/account basis
          >     3) End-user driven AS number on a per network basis (for
         bring your
          >     own AS and IP scenario)
          >
          >     Thoughts?
          >
          >     Cheers
          >     Alex
          >
          >
          >
          >
          >     -----Original Message-----
          >     From: Wido den Hollander <w...@widodh.nl
         <mailto:w...@widodh.nl> <mailto:w...@widodh.nl
         <mailto:w...@widodh.nl>>>
          >     Sent: 13 July 2021 15:08
          >     To: dev@cloudstack.apache.org
         <mailto:dev@cloudstack.apache.org>
         <mailto:dev@cloudstack.apache.org
         <mailto:dev@cloudstack.apache.org>>;
          >     Alex Mattioli <alex.matti...@shapeblue.com
         <mailto:alex.matti...@shapeblue.com>
          >     <mailto:alex.matti...@shapeblue.com
         <mailto:alex.matti...@shapeblue.com>>>
          >     Cc: Wei Zhou <wei.z...@shapeblue.com
         <mailto:wei.z...@shapeblue.com>
          >     <mailto:wei.z...@shapeblue.com
         <mailto:wei.z...@shapeblue.com>>>; Rohit Yadav
          >     <rohit.ya...@shapeblue.com
         <mailto:rohit.ya...@shapeblue.com>
         <mailto:rohit.ya...@shapeblue.com
         <mailto:rohit.ya...@shapeblue.com>>>;
          >     Gabriel Beims Bräscher <gabr...@pcextreme.nl
         <mailto:gabr...@pcextreme.nl>
          >     <mailto:gabr...@pcextreme.nl <mailto:gabr...@pcextreme.nl

          >     Subject: Re: IPV6 in Isolated/VPC networks
          >
          >
          >
          >     On 7/7/21 1:16 PM, Alex Mattioli wrote:
          >      > Hi all,
          >      > @Wei Zhou<mailto:wei.z...@shapeblue.com
         <mailto:wei.z...@shapeblue.com>
          >     <mailto:wei.z...@shapeblue.com
         <mailto:wei.z...@shapeblue.com>>> @Rohit
          >     Yadav<mailto:rohit.ya...@shapeblue.com
         <mailto:rohit.ya...@shapeblue.com>
          >     <mailto:rohit.ya...@shapeblue.com
         <mailto:rohit.ya...@shapeblue.com>>> and myself are
         investigating how
          >     to enable IPV6 support on Isolated and VPC networks and
         would like
          >     your input on it.
          >      > At the moment we are looking at implementing FRR with
         BGP (and
          >     possibly OSPF) on the ACS VR.
          >      >
          >      > We are looking for requirements, recommendations,
         ideas, rants,
          >     etc...etc...
          >      >
          >
          >     Ok! Here we go.
          >
          >     I think that you mean that the VR will actually route the
         IPv6
          >     traffic and for that you need to have a way of getting a
         subnet
          >     routed to the VR.
          >
          >     BGP is probably you best bet here. Although OSPFv3
         technically
          >     supports this it is very badly implemented in Frr for
         example.
          >
          >     Now FRR is a very good router and one of the fancy
         features it
          >     supports is BGP Unnumered. This allows for auto
         configuration of BGP
          >     over a L2 network when both sides are sending Router
         Advertisements.
          >     This is very easy for flexible BGP configurations where
         both sides
          >     have dynamic IPs.
          >
          >     What you want to do is that you get a /56, /48 or
         something which is
          >      >/64 bits routed to the VR.
          >
          >     Now you can sub-segment this into separate /64 subnets.
         You don't
          >     want to go smaller then a /64 is that prevents you from
         using SLAAC
          >     for IPv6 address configuration. This is how it works for
         Shared
          >     Networks now in Basic and Advanced Zones.
          >
          >     FRR can now also send out the Router Advertisements on
         the downlinks
          >     sending out:
          >
          >     - DNS servers
          >     - DNS domain
          >     - Prefix (/64) to be used
          >
          >     There is no need for DHCPv6. You can calculate the IPv6
         address the
          >     VM will obtain by using the MAC and the prefix.
          >
          >     So in short:
          >
          >     - Using BGP you routed a /48 to the VR
          >     - Now you split this into /64 subnets towards the
         isolated networks
          >
          >     Wido
          >
          >      > Alex Mattioli
          >      >
          >      >
          >      >
          >      >
          >
          >
          >
          > --
          > Regards,
          > Hean Seng



     --
     Regards,
     Hean Seng



--
Regards,
Hean Seng



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