On 7/6/21 1:02 PM, Guillaume Nault wrote: > On Thu, Jul 01, 2021 at 09:38:44AM -0600, David Ahern wrote: >> On 7/1/21 8:59 AM, Guillaume Nault wrote: >>> I first tried to write this selftest using VRFs, but there were some >>> problems that made me switch to namespaces (I don't remember precisely >>> which ones, probably virtual tunnel devices in collect_md mode). >> >> if you hit a problem with the test not working, send me the test script >> and I will take a look. > > So I've looked again at what it'd take to make a VRF-based selftest. > The problem is that we currently can't create collect_md tunnel > interfaces in different VRFs, if the VRFs are part of the same netns. > > Most tunnels explicitely refuse to create a collect_md device if > another one already exists in the netns, no matter the rest of the > tunnel parameters. This is the behaviour of ip_gre, ipip, ip6_gre and > ip6_tunnel. > > Then there's sit, which allows the creation of the second collect_md > device in the other VRF. However, iproute2 doesn't set the > IFLA_IPTUN_LINK attribute when it creates an external device, so it > can't set up such a configuration. > > Bareudp simply doesn't support VRF. > > Finally, vxlan allows devices with different IFLA_VXLAN_LINK attributes > to be created, but only when VXLAN_F_IPV6_LINKLOCAL is set. Removing > the VXLAN_F_IPV6_LINKLOCAL test at the end of vxlan_config_validate() > is enough to make two VXLAN-GPE devices work in a multi-VRF setup: Thanks for the details. In short, some work is needed to extend VRF support to these tunnels. That is worth doing if you have the time.
