Every time I boot xenserver/xcp-ng I have to bridge the interfaces for my IDS to get TAP traffic. My IDS runs this at boot to ssh in and do it.

setup_ids.rb

#!/usr/bin/ruby

require 'net/ssh'

bridges = ["xenbr3", "xenbr4", "xenbr5"]
bridge_interfaces = {
	"xenbr3" => "eth3",
	"xenbr4" => "eth4",
	"xenbr5" => "eth5"
}
bridge_vifs = {}

begin
	ssh = Net::SSH.start("hypervisor", "root")
rescue
	retry
end

vif_lines = ssh.exec!("ovs-vsctl show").split("\n")

bridges.each do |bridge|
	grabbing = false
	vif_lines.each do |line|
		if line == "    Bridge \"#{bridge}\""
			grabbing = true
		end
		if grabbing
			if line.include? "        Port \"vif"
				bridge_vifs[bridge] = line[/vif\d+.\d+/]
				grabbing = false
			end
		end
		next
	end
end

bridge_vifs.each do |bridge, vif|
	interface = bridge_interfaces[bridge]
	ssh.exec! "ovs-vsctl -- set Bridge #{bridge} mirrors=@m -- --id=@#{interface} get Port #{interface} -- --id=@#{vif} get Port #{vif} -- --id=@m create Mirror name=#{interface}-mirror select-dst-port=@#{interface} select-src-port=@#{interface} output-port=@#{vif}"
end