[RFC,5/5] tools/examples: Examples Linux bridge VLAN config

Commit Message

Leigh Brown May 3, 2024, 2:41 p.m. UTC

Add a new directory linux-bridge-vlan showing how to configure
systemd-networkd to support a bridge VLAN configuration.

Signed-off-by: Leigh Brown <[e-mail]>
---
 tools/examples/linux-bridge-vlan/README       | 52 +++++++++++++++++++
 tools/examples/linux-bridge-vlan/br0.netdev   |  7 +++
 tools/examples/linux-bridge-vlan/br0.network  |  8 +++
 .../examples/linux-bridge-vlan/enp0s0.network | 16 ++++++
 4 files changed, 83 insertions(+)
 create mode 100644 tools/examples/linux-bridge-vlan/README
 create mode 100644 tools/examples/linux-bridge-vlan/br0.netdev
 create mode 100644 tools/examples/linux-bridge-vlan/br0.network
 create mode 100644 tools/examples/linux-bridge-vlan/enp0s0.network

Patch

diff --git a/tools/examples/linux-bridge-vlan/README b/tools/examples/linux-bridge-vlan/README
new file mode 100644
index 0000000000..b287710e0f
--- /dev/null
+++ b/tools/examples/linux-bridge-vlan/README
@@ -0,0 +1,52 @@ 
+Linux Xen Dom0 single bridge multiple VLAN configuration with systemd
+=====================================================================
+
+Introduction
+------------
+
+This directory contains example files to be placed in /etc/systemd/network
+to enable a single bridge with multiple VLAN support.
+
+The example is to support the scenario where the Xen host network interface
+is connected to an Ethernet switch configured as a trunk port. Each domain
+VIF can then be configured with the VLAN id (vid) of the required VLAN.
+
+The example files create a bridge device called br0, with a physical interface 
+called enp0s0. You will need to update this with your system's device name.
+
+Key points of the configuration are:
+
+1. In br0.netdev, VLANFiltering=on is set. This is required to ensure the
+   VLAN tags are handled correctly.  If it is not set then the packets
+   from the vif interfaces will not have the correct VLAN tags set.  I
+   observed them with the pvid in the switch MAC address table.
+
+2. In br0.network, a system IPv4 address is configured that can be updated
+   according to your local network settings.
+
+3. In enp0s0.network, Bridge=br0 sets the bridge device to connect to and
+   there is a [BridgeVLAN] section for each VLAN you want to give access
+   to the switch. Note, if you want to create an internal VLAN private to
+   the host, do not include that VLAN id in this file.
+
+
+Domain configuration
+--------------------
+
+Add the vid= keyword to the vif definition in the domain. For example:
+
+vif = [ 'mac=xx:xx:xx:xx:xx:xx, bridge=br0, vid=10' ]
+
+
+Hints and tips
+--------------
+
+1. To check if vlan_filtering is enabled, run:
+   # cat /sys/devices/virtual/net/<name>/bridge/vlan_filtering
+
+2. To check the bridge port VLAN assignments, run:
+   # bridge vlan
+
+3. To check the vid setting in the xenstore, run:
+   # xenstore-ls -f | grep 'vid ='
+
diff --git a/tools/examples/linux-bridge-vlan/br0.netdev b/tools/examples/linux-bridge-vlan/br0.netdev
new file mode 100644
index 0000000000..ae1fe487c3
--- /dev/null
+++ b/tools/examples/linux-bridge-vlan/br0.netdev
@@ -0,0 +1,7 @@ 
+[NetDev]
+Name=br0
+Kind=bridge
+MACAddress=xx:xx:xx:xx:xx:xx
+
+[Bridge]
+VLANFiltering=on
diff --git a/tools/examples/linux-bridge-vlan/br0.network b/tools/examples/linux-bridge-vlan/br0.network
new file mode 100644
index 0000000000..b56203b66a
--- /dev/null
+++ b/tools/examples/linux-bridge-vlan/br0.network
@@ -0,0 +1,8 @@ 
+[Match]
+Name=br0
+
+[Network]
+DNS=8.8.8.8
+#Domains=example.com
+Address=10.1.1.10/24
+Gateway=10.1.1.1
diff --git a/tools/examples/linux-bridge-vlan/enp0s0.network b/tools/examples/linux-bridge-vlan/enp0s0.network
new file mode 100644
index 0000000000..6ee3154dfc
--- /dev/null
+++ b/tools/examples/linux-bridge-vlan/enp0s0.network
@@ -0,0 +1,16 @@ 
+[Match]
+Name=enp0s0
+
+[Network]
+Bridge=br0
+
+# If Jumbo frames are required
+#[Link]
+#MTUBytes=9000
+
+[BridgeVLAN]
+VLAN=10
+
+[BridgeVLAN]
+VLAN=20
+