Systems and methods involve compute nodes configured to define and/or otherwise process information associated with one or more virtual machines. In one exemplary implementation, a compute node may be configured to enable a firewall between the virtual machine and at least a portion of a network. Moreover, the firewall may be configured to detect undesired traffic based on a list of rules or an Ethernet bridge table associated with communication between the virtual machine and the network. Various features may also relate to the compute node being configured to lock the virtual machine in response to the firewall detecting undesired traffic associated with the virtual machine.