[arch-general] VLAN config works only partially

[Thore Bödecker]

Hi,

I think your issue might be that you seem to have DHCP enabled for the
enp2s0.network *and* enp2s0.1 which appear to be in the same layer 2
domain.

Usually VLAN id 1 is implicit as untagged/default.
So if you configured the switch port to add VLAN ids 2 and 7 in tagged
mode, VLAN id 1 likely remained the default untagged VLAN on this
port.
In this case, you don't need to define a VLAN device for VLAN id 1 as
it already accesible directly on enp2s0.

If you truely want to separate these 3 VLANs into their own VLAN
devices, you should configure a different VLAN as untagged on this
port (in the switch) and also stop doing DHCP on enp2s0 (only do that on
the VLAN interfaces).


Cheers,
Thore

On 22.01.22 18:40, Rainer Dorsch via arch-general wrote:
> Hi,
>
> I configured my network with multiple VLANs. I started with the description at
>
> https://wiki.archlinux.org/title/VLAN#systemd-networkd
>
>
>
> My current configuration:
>
> [n3150 ~]# cat /etc/systemd/network/enp2s0.network
> [Match]
> Name=enp2s0
>
> [Link]
> ActivationPolicy=Manual
>
> [Network]
> Description=The unconfigured physical ethernet device
>
> # In case of 'tagged only' setups, you probably don't need any IP
> # configuration on the link without VLAN (or: default VLAN).
> # For that just omit an [Address] section and disable all the
> # autoconfiguration magic like this:
> LinkLocalAddressing=no
> LLDP=no
> EmitLLDP=no
> IPv6AcceptRA=no
> IPv6SendRA=no
>
>
> ;these are arbitrary names, but must match the *.netdev and *.network files
> VLAN=enp2s0.1
> VLAN=enp2s0.2
> VLAN=enp2s0.7
>
> [DHCPv4]
> UseDNS=false
> [n3150 ~]#
>
> The VLAN config is simple, e.g.
>
> n3150% cat /etc/systemd/network/enp2s0.2.netdev
> [NetDev]
> Name=enp2s0.2
> Kind=vlan
>
> [VLAN]
> Id=2%
> n3150% cat /etc/systemd/network/enp2s0.2.network
> [Match]
> Name=enp2s0.2
>
> [Network]
> DHCP=yes
> Hostname=n3150-wlan
>
>
> n3150%
>
>
>
> The resulting routes:
>
> n3150% ip route
> default via 192.168.0.1 dev enp2s0.1 proto dhcp src 192.168.0.206 metric 1024
> default via 192.168.2.1 dev enp2s0.2 proto dhcp src 192.168.2.206 metric 1024
> default via 192.168.7.1 dev enp2s0.7 proto dhcp src 192.168.7.206 metric 1024
> default via 192.168.0.1 dev enp2s0 proto dhcp metric 20100
> 192.168.0.0/24 dev enp2s0 proto kernel scope link src 192.168.0.206 metric 100
> 192.168.0.0/24 dev enp2s0.1 proto kernel scope link src 192.168.0.206 metric
> 1024
> 192.168.0.1 dev enp2s0.1 proto dhcp scope link src 192.168.0.206 metric 1024
> 192.168.2.0/24 dev enp2s0.2 proto kernel scope link src 192.168.2.206 metric
> 1024
> 192.168.2.1 dev enp2s0.2 proto dhcp scope link src 192.168.2.206 metric 1024
> 192.168.7.0/24 dev enp2s0.7 proto kernel scope link src 192.168.7.206 metric
> 1024
> 192.168.7.1 dev enp2s0.7 proto dhcp scope link src 192.168.7.206 metric 1024
> n3150%
>
> Unfortunately, the 192.168.0.* network is not reachable without explicitly
> deleting the routes for enp2s0:
>
> [n3150 ~]# ping 192.168.0.30
> PING 192.168.0.30 (192.168.0.30) 56(84) Bytes an Daten.
> ^C
> --- 192.168.0.30 ping-Statistik ---
> 2 Pakete übertragen, 0 empfangen, 100% packet loss, time 1016ms
>
> [n3150 ~]# ip route del default via 192.168.0.1 dev enp2s0 proto dhcp metric
> 20100
> [n3150 ~]# ip route del 192.168.0.0/24 dev enp2s0 proto kernel scope link src
> 192.168.0.206 metric 100
> [n3150 ~]# ping 192.168.0.30
> PING 192.168.0.30 (192.168.0.30) 56(84) Bytes an Daten.
> 64 Bytes von 192.168.0.30: icmp_seq=1 ttl=64 Zeit=0.699 ms
> 64 Bytes von 192.168.0.30: icmp_seq=2 ttl=64 Zeit=0.287 ms
> ^C
> --- 192.168.0.30 ping-Statistik ---
> 2 Pakete übertragen, 2 empfangen, 0% packet loss, time 1010ms
> rtt min/avg/max/mdev = 0.287/0.493/0.699/0.206 ms
> [n3150 ~]#
>
> Can anybody tell how I can avoid the routes for enp2s0 get configured?
>
> Thanks
> Rainer



--
Thore "foxxx0" Bödecker

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