[pve-devel] [PATCH pve-network] controllers: bgp: split v4 && v6 peers in different groups

Stefan Hanreich s.hanreich at proxmox.com
Wed Mar 12 18:40:46 CET 2025


gave this a quick spin on my test cluster, notes below

On 12/19/24 17:17, Alexandre Derumier wrote:
> reported by user on the forum:
> https://forum.proxmox.com/threads/sdn-mismatch-afi-with-bgp-controller-ipv6-session.159250/
> 
> This is for dualstack, when evpn is ipv4, and bgp is ipv6+(ipv4)
> 
> Signed-off-by: Alexandre Derumier <alexandre.derumier at groupe-cyllene.com>
> ---
>  src/PVE/Network/SDN/Controllers/BgpPlugin.pm  | 43 ++++++++-----
>  .../bgp_ipv4_ipv6/expected_controller_config  | 63 +++++++++++++++++++
>  .../bgp_ipv4_ipv6/expected_sdn_interfaces     | 41 ++++++++++++
>  src/test/zones/evpn/bgp_ipv4_ipv6/interfaces  | 11 ++++
>  src/test/zones/evpn/bgp_ipv4_ipv6/sdn_config  | 48 ++++++++++++++
>  5 files changed, 192 insertions(+), 14 deletions(-)
>  create mode 100644 src/test/zones/evpn/bgp_ipv4_ipv6/expected_controller_config
>  create mode 100644 src/test/zones/evpn/bgp_ipv4_ipv6/expected_sdn_interfaces
>  create mode 100644 src/test/zones/evpn/bgp_ipv4_ipv6/interfaces
>  create mode 100644 src/test/zones/evpn/bgp_ipv4_ipv6/sdn_config
> 
> diff --git a/src/PVE/Network/SDN/Controllers/BgpPlugin.pm b/src/PVE/Network/SDN/Controllers/BgpPlugin.pm
> index 53963e5..24828db 100644
> --- a/src/PVE/Network/SDN/Controllers/BgpPlugin.pm
> +++ b/src/PVE/Network/SDN/Controllers/BgpPlugin.pm
> @@ -94,28 +94,43 @@ sub generate_controller_config {
>  
>      push @controller_config, "bgp bestpath as-path multipath-relax" if $multipath_relax;
>  
> +    my $peers_ipversion = { 4 => [], 6 => [] };
> +    foreach my $address (@peers) {
> +	my $ipversion = Net::IP::ip_is_ipv6($address) ? "6" : "4";
> +	push (@{$peers_ipversion->{$ipversion}}, $address);
> +    }
> +
>      #BGP neighbors
> -    if(@peers) {
> -	push @controller_config, "neighbor BGP peer-group";
> -	push @controller_config, "neighbor BGP remote-as $remoteas";
> -	push @controller_config, "neighbor BGP bfd";
> -	push @controller_config, "neighbor BGP ebgp-multihop $ebgp_multihop" if $ebgp && $ebgp_multihop;
> +    for my $version (sort keys %$peers_ipversion) {
> +	next if !@{$peers_ipversion->{$version}};
> +	$version = "" if $version eq '4';
> +	push @controller_config, "neighbor BGP${version} peer-group";
> +	push @controller_config, "neighbor BGP${version} remote-as $remoteas";
> +	push @controller_config, "neighbor BGP${version} bfd";
> +	push @controller_config, "neighbor BGP${version} ebgp-multihop $ebgp_multihop" if $ebgp && $ebgp_multihop;
>      }
>  
>      # BGP peers
> -    foreach my $address (@peers) {
> -	push @controller_config, "neighbor $address peer-group BGP";
> +    for my $version (sort keys %$peers_ipversion) {
> +	for my $address (@{$peers_ipversion->{$version}}) {
> +	    $version = "" if $version eq '4';
> +	    push @controller_config, "neighbor $address peer-group BGP${version}";
> +	}
>      }
> +
>      push(@{$bgp->{""}}, @controller_config);
>  
>      # address-family unicast
> -    if (@peers) {
> -	my $ipversion = Net::IP::ip_is_ipv6($ifaceip) ? "ipv6" : "ipv4";
> -	my $mask = Net::IP::ip_is_ipv6($ifaceip) ? "/128" : "32";
> -
> -	push(@{$bgp->{"address-family"}->{"$ipversion unicast"}}, "network $ifaceip/$mask") if $loopback;
> -	push(@{$bgp->{"address-family"}->{"$ipversion unicast"}}, "neighbor BGP activate");
> -	push(@{$bgp->{"address-family"}->{"$ipversion unicast"}}, "neighbor BGP soft-reconfiguration inbound");
> +    for my $version (sort keys %$peers_ipversion) {
> +	next if !@{$peers_ipversion->{$version}};
> +	my $ipversion = "ipv${version}";
> +	$version = "" if $version eq '4';
> +	if($loopback) {
> +	    my $mask = Net::IP::ip_is_ipv6($ifaceip) ? "/128" : "32";
> +	    push(@{$bgp->{"address-family"}->{"$ipversion unicast"}}, "network $ifaceip/$mask");


It should work for redistributing EVPN routes via BGP, but if you want
to use the BGP controller with loopback + multiple address families this
doesn't seem to work. My generated configuration looks like this if I
try to do dual-stack BGP:

 address-family ipv6 unicast
  network 172.20.1.1/32
  neighbor BGP6 activate
  neighbor BGP6 soft-reconfiguration inbound
 exit-address-family

This should take the IPv6 from the loopback, right? We would also need
to create a correct_src_ipv6 route map then I suppose. Not sure how much
sense a dual-stack underlay makes, maybe when transitioning from 4 to 6?


If I have no IPv4 on my loopback and try an IPv6 only BGP underlay
(peers are only IPv6, loopback is IPv6 /128), then it fails on creating
a router-id:

TASK ERROR: can't autofind a router-id value from ip or mac at
/usr/share/perl5/PVE/Network/SDN/Controllers/Plugin.pm line 135.


Not 100% sure why that is, I will need to check tomorrow, I think it is
because we are only checking the address field of the interfaces file
(in find_local_ip_interface_peers), but IPv6 addresses are in the
address6 field. That seems to break when using IPv6.

Reading the MAC from "/sys/class/net/$iface/master/address" also doesn't
always work if the interface is not part of a bridge. I have my ptp
links configured directly on the interfaces, so that might also be a
problem.


Redistributing IPv4 and IPv6 routes from an EVPN zone exit-node worked
on my machine with this patch.

> +	}
> +	push(@{$bgp->{"address-family"}->{"$ipversion unicast"}}, "neighbor BGP${version} activate");
> +	push(@{$bgp->{"address-family"}->{"$ipversion unicast"}}, "neighbor BGP${version} soft-reconfiguration inbound");
>      }
>  
>      if ($loopback) {
> diff --git a/src/test/zones/evpn/bgp_ipv4_ipv6/expected_controller_config b/src/test/zones/evpn/bgp_ipv4_ipv6/expected_controller_config
> new file mode 100644
> index 0000000..a5671c8
> --- /dev/null
> +++ b/src/test/zones/evpn/bgp_ipv4_ipv6/expected_controller_config
> @@ -0,0 +1,63 @@
> +frr version 8.5.2
> +frr defaults datacenter
> +hostname localhost
> +log syslog informational
> +service integrated-vtysh-config
> +!
> +!
> +vrf vrf_myzone
> + vni 1000
> +exit-vrf
> +!
> +router bgp 65000
> + bgp router-id 192.168.0.1
> + no bgp hard-administrative-reset
> + no bgp default ipv4-unicast
> + coalesce-time 1000
> + no bgp graceful-restart notification
> + neighbor VTEP peer-group
> + neighbor VTEP remote-as 65000
> + neighbor VTEP bfd
> + neighbor 192.168.0.2 peer-group VTEP
> + neighbor 192.168.0.3 peer-group VTEP
> + neighbor BGP peer-group
> + neighbor BGP remote-as 65000
> + neighbor BGP bfd
> + neighbor BGP6 peer-group
> + neighbor BGP6 remote-as 65000
> + neighbor BGP6 bfd
> + neighbor 192.168.0.10 peer-group BGP
> + neighbor 2a08:2142:302:3::2 peer-group BGP6
> + !
> + address-family ipv4 unicast
> +  neighbor BGP activate
> +  neighbor BGP soft-reconfiguration inbound
> + exit-address-family
> + !
> + address-family ipv6 unicast
> +  neighbor BGP6 activate
> +  neighbor BGP6 soft-reconfiguration inbound
> + exit-address-family
> + !
> + address-family l2vpn evpn
> +  neighbor VTEP activate
> +  neighbor VTEP route-map MAP_VTEP_IN in
> +  neighbor VTEP route-map MAP_VTEP_OUT out
> +  advertise-all-vni
> + exit-address-family
> +exit
> +!
> +router bgp 65000 vrf vrf_myzone
> + bgp router-id 192.168.0.1
> + no bgp hard-administrative-reset
> + no bgp graceful-restart notification
> +exit
> +!
> +route-map MAP_VTEP_IN permit 1
> +exit
> +!
> +route-map MAP_VTEP_OUT permit 1
> +exit
> +!
> +line vty
> +!
> \ No newline at end of file
> diff --git a/src/test/zones/evpn/bgp_ipv4_ipv6/expected_sdn_interfaces b/src/test/zones/evpn/bgp_ipv4_ipv6/expected_sdn_interfaces
> new file mode 100644
> index 0000000..4cf13e0
> --- /dev/null
> +++ b/src/test/zones/evpn/bgp_ipv4_ipv6/expected_sdn_interfaces
> @@ -0,0 +1,41 @@
> +#version:1
> +
> +auto myvnet
> +iface myvnet
> +	address 10.0.0.1/24
> +	bridge_ports vxlan_myvnet
> +	bridge_stp off
> +	bridge_fd 0
> +	mtu 1450
> +	ip-forward on
> +	arp-accept on
> +	vrf vrf_myzone
> +
> +auto vrf_myzone
> +iface vrf_myzone
> +	vrf-table auto
> +	post-up ip route add vrf vrf_myzone unreachable default metric 4278198272
> +
> +auto vrfbr_myzone
> +iface vrfbr_myzone
> +	bridge-ports vrfvx_myzone
> +	bridge_stp off
> +	bridge_fd 0
> +	mtu 1450
> +	vrf vrf_myzone
> +
> +auto vrfvx_myzone
> +iface vrfvx_myzone
> +	vxlan-id 1000
> +	vxlan-local-tunnelip 192.168.0.1
> +	bridge-learning off
> +	bridge-arp-nd-suppress on
> +	mtu 1450
> +
> +auto vxlan_myvnet
> +iface vxlan_myvnet
> +	vxlan-id 100
> +	vxlan-local-tunnelip 192.168.0.1
> +	bridge-learning off
> +	bridge-arp-nd-suppress on
> +	mtu 1450
> diff --git a/src/test/zones/evpn/bgp_ipv4_ipv6/interfaces b/src/test/zones/evpn/bgp_ipv4_ipv6/interfaces
> new file mode 100644
> index 0000000..36e97ce
> --- /dev/null
> +++ b/src/test/zones/evpn/bgp_ipv4_ipv6/interfaces
> @@ -0,0 +1,11 @@
> +auto vmbr0
> +iface vmbr0 inet static
> +	address 192.168.0.1/24
> +	gateway 192.168.0.254
> +        bridge-ports eth0
> +        bridge-stp off
> +        bridge-fd 0
> +
> +auto vmbr0
> +iface vmbr0 inet6 static
> +        address 2a08:2142:302:3::1/64
> diff --git a/src/test/zones/evpn/bgp_ipv4_ipv6/sdn_config b/src/test/zones/evpn/bgp_ipv4_ipv6/sdn_config
> new file mode 100644
> index 0000000..e5674bf
> --- /dev/null
> +++ b/src/test/zones/evpn/bgp_ipv4_ipv6/sdn_config
> @@ -0,0 +1,48 @@
> +{
> +    version => 1,
> +    vnets => {
> +        ids => {
> +            myvnet => {
> +                tag => "100",
> +                type => "vnet",
> +                zone => "myzone",
> +            },
> +        },
> +    },
> +
> +    zones   => {
> +        ids => {
> +            myzone => {
> +                ipam => "pve",
> +                type => "evpn",
> +                controller => "evpnctl",
> +                'vrf-vxlan' => 1000,
> +            },
> +        },
> +    },
> +    controllers  => {
> +        ids => {
> +            evpnctl => {
> +                type => "evpn",
> +                'peers' => '192.168.0.1,192.168.0.2,192.168.0.3',
> +                asn => "65000",
> +            },
> +            localhost => {
> +                type => "bgp",
> +                'peers' => '192.168.0.10,2a08:2142:302:3::2',
> +                asn => "65000",
> +                node => "localhost",
> +            },
> +        },
> +    },
> +
> +    subnets => {
> +        ids => {
> +            'myzone-10.0.0.0-24' => {
> +                'type' => 'subnet',
> +                'vnet' => 'myvnet',
> +                'gateway' => '10.0.0.1',
> +            },
> +        },
> +    },
> +}





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