const golang.org/x/sys/unix.IFLA_VXLAN_UDP_CSUM

one use

	golang.org/x/sys/unix (current package)
		ztypes_linux.go#L1680: 	IFLA_VXLAN_UDP_CSUM                        = 0x12

The pages are generated with Golds v0.4.9. (GOOS=linux GOARCH=amd64)