LFCS Certification Firewall and Packet Filtering 2

Question 1

Which iptables table is used for Network Address Translation (NAT)?

Accepted Answer

nat

Answer

The 'nat' table is specifically designed for NAT operations including SNAT, DNAT, and MASQUERADE.

Question 2

What iptables command lists all rules in the filter table with line numbers?

Accepted Answer

iptables -L -v --line-numbers

Answer

The '-L -v --line-numbers' flags list all rules verbosely with line numbers for easy reference and deletion.

Question 3

Which firewalld zone is most appropriate for a network interface connected to the public internet?

Accepted Answer

public

Answer

The 'public' zone assumes the network is untrusted and only allows selected incoming connections.

Question 4

How do you make firewalld rule changes permanent so they survive a reboot?

Accepted Answer

firewall-cmd --permanent followed by --reload

Answer

The --permanent flag writes rules to disk, and --reload applies them to the running configuration.

Question 5

In nftables, what command adds a new table named 'mytable' with the inet family?

Accepted Answer

nft add table inet mytable

Answer

The 'nft add table' command creates a new nftables table with the specified address family.

LFCS Certification Practice Test