OVH, IPv6 with /64 prefix, Proxmox and Pfsense. SOLVED

pasdif

Active Member
Dec 5, 2019
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Hello everyone.

After several days where I was about to go crazy, I finally managed to configure an OVH baremetal server with Proxmox and manage to use IPv6 addresses also on Pfsense and the virtual machines behind it.

I hope these hints will help some of you.

I should mention that I am not very knowledgeable about IPv6. I have for days been looking for solutions both on OVH documentation and in this forum. None of them gave any real help.

Another thing. On another OVH server but with a /56 prefix I had no problem. The routing works perfectly without any effort. Whereas for the server with a /64 prefix everything became a mystery, at least for me, and a nightmare.

Let's start with the configuration of Proxmox and IPv6.

I added the main IPv6 address and configured the gateway on the main interface vmbr0

1737276109911.png


I installed the npd6 package and configured npd6.conf with

prefix=2001:41d0:203:xxxx::
interface = vmbr0

and started the service

I entered the following lines in /etc/sysctl.conf

net.ipv6.conf.all.forwarding=1
net.ipv6.conf.all.proxy_ndp=1


and ran sysctl -p

Let's move on to Pfsense. I take it for granted that everything related to IPv4 is already working.

To the WAN interface I have assigned the address 2001:41d0:203:xxxx::1/64 and set the IPv6 gateway with address 2001:41d0:203:xxxx::, so the gateway is the Proxmox server itself

On the LAN port I assigned a private IPv6 address fddd:eeee:eeee::1:1/24

Clearly, the necessary NAT and firewall rules were then made

The virtual machine has as IPv6 address fddd:eeee:eeee::1:11/24 and as gateway fddd:eeee:eeee::1:1

Everything works perfectly, both outgoing and incoming from both Pfsense and the virtual machine.

I hope this little guide can help someone

Regards
Pasquale