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> 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> 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>> >> 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>> >> > Sent: 13 July 2021 15:08 >> > To: dev@cloudstack.apache.org <mailto:dev@cloudstack.apache.org>; >> > Alex Mattioli <alex.matti...@shapeblue.com >> > <mailto:alex.matti...@shapeblue.com>> >> > Cc: Wei Zhou <wei.z...@shapeblue.com >> > <mailto:wei.z...@shapeblue.com>>; Rohit Yadav >> > <rohit.ya...@shapeblue.com <mailto:rohit.ya...@shapeblue.com>>; >> > Gabriel Beims Bräscher <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>> @Rohit >> > Yadav<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
