COMPUTER THREATS SECURITY
WHAT IS A FIREWALL IN NETWORK SECURITY
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Input chain, forward chain and output chain are configured
|
|
|
Input chain and output chain are found no forward chain
|
|
|
Either A or B
|
|
|
None of the above
|
Detailed explanation-1: -INPUT-Alters network packets targeted for the host. OUTPUT-Alters locally-generated network packets before they are sent out. FORWARD-Alters network packets routed through the host. PREROUTING-Alters incoming network packets before they are routed. POSTROUTING-Alters network packets before they are sent out.
Detailed explanation-2: -iptables is a command line interface used to set up and maintain tables for the Netfilter firewall for IPv4, included in the Linux kernel. The firewall matches packets with rules defined in these tables and then takes the specified action on a possible match.
Detailed explanation-3: -The INPUT and OUTPUT chains handle packets originating from or destined for the host system. The FORWARD chain handles packets just passing through the host system. The nat table also has three built-in chains: PREROUTING, POSTROUTING, and OUTPUT. mangle has only two chains: PREROUTING and OUTPUT.
Detailed explanation-4: -The three built-in chains of iptables (that is, the chains that affect every packet which traverses a network) are INPUT, OUTPUT, and FORWARD. These chains are permanent and cannot be deleted. The-j target option specifies the location in the iptables ruleset where this particular rule should jump.