zones: evpn: add a default unreachable, to prevent vrf leak

On Linux, when no route is found in a vrf, it somehow fallback
to the default routing table. In our case, that means a leak
from the overlay to the underlay.
Adding a low priority unreachable catch-all route is the way to go, as
per the doc: https://www.kernel.org/doc/Documentation/networking/vrf.txt

Signed-off-by: Alexandre Bruyelles <git@jack.fr.eu.org>

diff --git a/PVE/Network/SDN/Zones/EvpnPlugin.pm b/PVE/Network/SDN/Zones/EvpnPlugin.pm
index e6ee839b1dcf4dd8ed8d251bafc4aaf576d51745..ca000cf6049d65680b908a884807031b323f7228 100644 (file)
--- a/PVE/Network/SDN/Zones/EvpnPlugin.pm
+++ b/PVE/Network/SDN/Zones/EvpnPlugin.pm
@@ -134,6 +134,7 @@ sub generate_sdn_config {
        #vrf interface
        @iface_config = ();
        push @iface_config, "vrf-table auto";
+       push @iface_config, "post-up ip route add vrf $vrf_iface unreachable default metric 4278198272";
        push(@{$config->{$vrf_iface}}, @iface_config) if !$config->{$vrf_iface};
 
        if ($vrfvxlan) {