Unable to update the kernel. Two possible causes:
1. Multiple ebtables programs were executing simultaneously. The ebtables
   userspace tool doesn't by default support multiple ebtables programs running
   concurrently. The ebtables option --concurrent or a tool like flock can be
   used to support concurrent scripts that update the ebtables kernel tables.
2. The kernel doesn't support a certain ebtables extension, consider
   recompiling your kernel or insmod the extension.
.

需要安裝模組kmod-ebtables-ipv4