[pve-devel] [PATCH manager/network 0/3] add IPv6 SLAAC for vnets in evpn zones

Hannes Laimer h.laimer at proxmox.com
Mon Jan 19 08:01:24 CET 2026


When we allow setting a ND prefix for the RAs to advertise, we could end
up with one that does not match the configured gateway one on a subnet.
We shouldn't allow setting the prefix explicitly, but just "enable
SLAAC" on a configured IPv6 subnet.

I'll send a v2 for this, sorry for the noise.

On 1/14/26 15:52, Hannes Laimer wrote:
> FRR natively supports sending RAs, if configured to do so, dnsmasq also
> doesn't seem to correctly send RAs in a VRF context. Both DHCPv4 and v6
> worked fine when running on a VNet, but RAs just wouldn't be send
> correctly. From a quick look it may have to the with dnsmasq not using
> the link-local address of the interface, or not sending it if the
> interface also has another address attached. [1][2] I did try building
> it myself with some changes, but could not get the RA packets to "hit
> the wire", they never showed up in tcpdump. So either they were not sent
> or the kernel dropped them cause they didn't have a ll source address.
> Regardless, these are the two reasons why I went with using FRR directly
> rather than using dnsmasq like we aleardy do for DHCPv4.
> 
> This series adds a `ipv6-nd-prefix`-option for vnets that is than used by
> client on the vnet to perform SLAAC. Without a prefix specified, SLAAC
> is not enabled.
> 
> [1] https://thekelleys.org.uk/gitweb1/?p=dnsmasq.git;a=blob;f=src/radv.c;h=aaf6b71e27ba392d7517c68fa90f251eccbf4641;hb=d8f66f4fda02ca50616f428d9c161c8ca1a0cb70#l308
> [2] https://thekelleys.org.uk/gitweb1/?p=dnsmasq.git;a=blob;f=src/dhcp6.c;h=482caf7dd492849f5a454316d86e759677c0072a;hb=d8f66f4fda02ca50616f428d9c161c8ca1a0cb70#l138
> 
> pve-network:
> 
> Hannes Laimer (2):
>    evpn: add ipv6 slaac support for vnets in an evpn zone
>    evpn: add test for vnets with a `ipv6-nd-prefix` set
> 
>   src/PVE/API2/Network/SDN/Vnets.pm             |  7 +++
>   src/PVE/Network/SDN/Controllers/EvpnPlugin.pm | 15 ++++++
>   src/PVE/Network/SDN/VnetPlugin.pm             |  8 +++
>   .../expected_controller_config                | 49 +++++++++++++++++++
>   .../ipv6_slaacprefix/expected_sdn_interfaces  | 42 ++++++++++++++++
>   .../zones/evpn/ipv6_slaacprefix/interfaces    |  7 +++
>   .../zones/evpn/ipv6_slaacprefix/sdn_config    | 39 +++++++++++++++
>   7 files changed, 167 insertions(+)
>   create mode 100644 src/test/zones/evpn/ipv6_slaacprefix/expected_controller_config
>   create mode 100644 src/test/zones/evpn/ipv6_slaacprefix/expected_sdn_interfaces
>   create mode 100644 src/test/zones/evpn/ipv6_slaacprefix/interfaces
>   create mode 100644 src/test/zones/evpn/ipv6_slaacprefix/sdn_config
> 
> 
> pve-manager:
> 
> Hannes Laimer (1):
>    ui: sdn: add `ipv6-nd-prefix` field to vnet form
> 
>   www/manager6/sdn/VnetEdit.js | 21 +++++++++++++++++++++
>   1 file changed, 21 insertions(+)
> 
> 
> Summary over all repositories:
>    8 files changed, 188 insertions(+), 0 deletions(-)
> 





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