Op 17-07-2021 om 06:28 schreef Hean Seng:
I think if doing this way ,  since you were to implement on peering ip
between vr and phsical router , then would need keep /56 or 48 at
Clodustack ?  We can only add /64 subnet to Cloudstack only (instead of
keep the /56 or 48 there).


We can have a /64 at CloudStack in which all VRs talk with the router of the ISP.

That is large enough as a interconnect subnet between the VRs and routers.

From there you can route /56, /48 or which size you want towards the VR.

From the interconnect /64 you can also grab IPs which you use for loadbalancing purposes over different VMs.


I  saw other software provider do is adding /64 subnet to their system,
and  after that allocate subnet to the VM (from the previous added list).

May be considering the OSPF if really on this.  It really a nightmare for
maintaining 1000 or few thousand of BGP session.   You can imagine your
Cisco Router list of few thousand BGP session there.


Yes, but I would suggest that both OSPFv3 and BGP should work. Not everybody will have 1000 accounts on their environment.

Even static routes should be supported.

Wido





On Fri, Jul 16, 2021 at 11:17 PM Wido den Hollander <w...@widodh.nl> wrote:



Op 16-07-2021 om 16:42 schreef Hean Seng:
Hi Wido,

In current setup,  each Cloudstack have own VR, so in this new  IPv6
subnet
allocation , each VR (which have Frr) will need to have peering with ISP
router (and either BGP or Static Route) , and there is 1000 Acocunts,  it
will 1000 BGP session with ISP router ,  Am I right for this ? or I
understand wrong .


Yes, that is correct. A /56 would also be sufficient or a /60 which is
enough to allocate a few /64 subnets.

1000 BGP connections isn't really a problem for a proper router at the
ISP. OSPF(v3) would be better, but as I said that's poorly supported.

The ISP could also install 1000 static routes, but that means that the
ISP's router needs to have those configured.

http://docs.frrouting.org/en/latest/ospf6d.html
(While looking up this URL I see that Frr recently put in a lot of work
in OSPFv3, seems better now)

I understand IPv6 is different then IPv4, and in IPv6 it suppose each
devices have own IP. It just how to realize in easy way.









On Fri, Jul 16, 2021 at 8:17 PM Wido den Hollander <w...@widodh.nl>
wrote:



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: d...@cloudstack.apache.org
           <mailto:d...@cloudstack.apache.org>
           <mailto:d...@cloudstack.apache.org
           <mailto:d...@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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