Final answer:
The firewall-session-dirty check-new command controls how new incoming sessions are handled by a firewall, making sure that they are checked against the firewall's security policies.
Step-by-step explanation:
The firewall-session-dirty check-new command is typically found in the configuration settings of network firewalls. This command likely controls how a firewall handles new incoming sessions that do not match any existing session in the firewall's session table. When this command is enabled, the firewall will check for new sessions and apply the necessary rules and policies to determine whether to allow or deny the traffic. It ensures that new sessions, which have no prior records or activities associated with them, undergo a scrutiny process according to the firewall's configured security policies before they are allowed to traverse the network.