VXlan breaks on dependent network restart

[bluewavenet]

@Darin755

For some reason, when either the Wifi or Wireguard interfaces restart the vxlan device does not get recreated. In order to recreate the vxlan device I end up having to either reboot OpenWRT or restart /etc/init.d/network. I think this might be a bug but I don’t see much in the logs to go off of. I did find some previous posts about this issue.

I refer to a previous thread:

@bluewavenet

One particular point to make note of is that vxlan requires the ip-full package to work correctly, but it is not a dependency.

The latest incarnation of vxlan support is built into the kernel. Current Luci or UCI config no longer supports all the required parameters, but like I said it works after a fashion, if you are lucky.

So currently you have to configure manually via a script.
Typically it would look something like this, for a default ipv6 config (ipv4 wont work properly for point to multi-point because it depends on multicast that is by default disabled for ipv4):

	ip -6 link add "vxlan$tun_id" \
		address "$vxmac_indexed" \
		type vxlan \
		id "$tun_id" \
		dstport 4789 \
		local "$link_local_addr" \
		group "ff02::$tun_id" \
		dev "$device" \
		ttl 5

	ip link set "vxlan$tun_id" up

Required parameters are:

1. tun_id the id number of the vxlan tunnel
2. dstport the port number to use for the tunnel comms
3. local the link local address of the vxlan node being configured
4. group the vxlan group multicast address to use
5. device the bridge device used to carry this vxlan tunnel
6. ttl the time to live for tunnel connections if no traffic is received

As you can see, this does not look anything like the uci config.
see: openwrt vxlan

And also note:

@_bernd

you can drop a simple script in the hot plug dir and restart the vxlan when the WG interfaces are brought up.