From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id 657721FF13B for ; Mon, 08 Jun 2026 11:46:46 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 8332F18652; Mon, 8 Jun 2026 11:46:44 +0200 (CEST) Date: Mon, 8 Jun 2026 11:46:40 +0200 From: Gabriel Goller To: Lukas Sichert Subject: Re: [PATCH network v2 1/5] sdn: evpn: enable force_forwarding for ipv6 forwarding to subnets Message-ID: Mail-Followup-To: Lukas Sichert , pve-devel@lists.proxmox.com References: <20260603142921.91174-1-l.sichert@proxmox.com> <20260603142921.91174-2-l.sichert@proxmox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260603142921.91174-2-l.sichert@proxmox.com> User-Agent: NeoMutt/20241002-35-39f9a6 X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1780911956961 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.028 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [evpnplugin.pm] Message-ID-Hash: E53ZA3XLARHTWFHHJEJZGSJQ6FMXWWKC X-Message-ID-Hash: E53ZA3XLARHTWFHHJEJZGSJQ6FMXWWKC X-MailFrom: g.goller@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: pve-devel@lists.proxmox.com X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On 03.06.2026 16:29, Lukas Sichert wrote: > EVPN zones can route IPv6 subnet traffic through a VNet and an outgoing > interface. Until now, this depended on global IPv6 forwarding state, > which also changes Router Advertisement handling for the whole host. > > Use the per-interface 'force_forwarding' setting instead. For IPv6 > subnets that need forwarding, generate post-up/post-down commands for > both the VNet interface and the outgoing interface. Track interfaces > that already received 'force_forwarding' commands to avoid duplicates > when multiple subnets share the same outgoing path. Update the expected > SDN interface output in the zone tests accordingly. > > Signed-off-by: Lukas Sichert > --- > src/PVE/Network/SDN/Zones/EvpnPlugin.pm | 20 +++++++++++++++---- > .../expected_sdn_interfaces | 4 ++++ > .../exitnode_snat/expected_sdn_interfaces | 4 ++++ > .../exitnodenullroute/expected_sdn_interfaces | 4 ++++ > .../evpn/ipv4ipv6/expected_sdn_interfaces | 4 ++++ > .../zones/evpn/ipv6/expected_sdn_interfaces | 4 ++++ > .../evpn/ipv6underlay/expected_sdn_interfaces | 4 ++++ > 7 files changed, 40 insertions(+), 4 deletions(-) > > diff --git a/src/PVE/Network/SDN/Zones/EvpnPlugin.pm b/src/PVE/Network/SDN/Zones/EvpnPlugin.pm > index dfbd7e9..7622457 100644 > --- a/src/PVE/Network/SDN/Zones/EvpnPlugin.pm > +++ b/src/PVE/Network/SDN/Zones/EvpnPlugin.pm > @@ -238,11 +238,13 @@ sub generate_sdn_config { > my $ipv6 = undef; > my $enable_forward_v4 = undef; > my $enable_forward_v6 = undef; > + my $force_forward_enabled = {}; > my $subnets = PVE::Network::SDN::Vnets::get_subnets($vnetid, 1); > foreach my $subnetid (sort keys %{$subnets}) { > my $subnet = $subnets->{$subnetid}; > my $cidr = $subnet->{cidr}; > my $mask = $subnet->{mask}; > + my $vnet = $subnet->{vnet}; > > my $gateway = $subnet->{gateway}; > if ($gateway) { > @@ -266,11 +268,21 @@ sub generate_sdn_config { > $enable_forward_v4 = 1 if $gateway; > } > > - if ($subnet->{snat}) { > + #find outgoing interface > + my ($outip, $outiface) = > + PVE::Network::SDN::Zones::Plugin::get_local_route_ip($checkrouteip); Hmm this is now outside the snat branch, so we will run `ip route get 8.8.8.8` for subnets without a gateway and with snat enabled, which will always fail. Could it be that without gateway or snat there isn't an outgoing interface and thus no need to set force_forwarding? > + > + if ($outiface && $enable_forward_v6 && !($force_forward_enabled->{$outiface})) { Will this enable force_forwarding on a ipv4 subnet if there is a ipv6 subnet that sets $enable_forward_v6 followed by a ipv4 subnet? I think we need to reset the $enable_forward_v6 variable before the loop? > + push @iface_config, > + "post-up echo 1 > /proc/sys/net/ipv6/conf/$outiface/force_forwarding"; > + push @iface_config, > + "post-down echo 0 > /proc/sys/net/ipv6/conf/$outiface/force_forwarding"; > + push @iface_config, "post-up echo 1 > /proc/sys/net/ipv6/conf/$vnet/force_forwarding"; > + push @iface_config, "post-down echo 0 > /proc/sys/net/ipv6/conf/$vnet/force_forwarding"; Could it happen here that with the post-down we can bring down a shared interface? e.g. if a zone/vnet use the same vmbr0 bridge and then deleting one removes the force_forwarding on the other one? Not sure if this can happen. If yes, we could either just remove the post-down or add some complicated ref-couting (not a fan of that). > + $force_forward_enabled->{$outiface} = 1; > + } > > - #find outgoing interface > - my ($outip, $outiface) = > - PVE::Network::SDN::Zones::Plugin::get_local_route_ip($checkrouteip); > + if ($subnet->{snat}) { > if ($outip && $outiface && $is_evpn_gateway) { > #use snat, faster than masquerade > push @iface_config, > [snip] Everything also applies to the simplezone afaics. Thanks for the patch!