What is the role of a Jump rule in custom chains?

• A. Transfers control to another chain
• B. Terminates the packet
• C. Rewrites the IP header
• D. Creates a new chain

Answer: (A)

Jump transfers processing to another chain. It works like calling a subroutine: when a rule with this action matches, the firewall begins evaluating the rules in the specified destination chain. This lets you modularize policies and reuse rule sets across different parts of your firewall. It does not terminate the packet by itself, nor rewrite headers—that would be handled by actions like drop/reject or NAT/mangle. It also doesn’t create a new chain; the destination chain must already exist. After the target chain finishes (typically via a return), execution resumes with the next rule after the Jump.