21 Consider the following series of commands from a Linux system: iptables -A input -p icmp -s 0/0 -d 0/0 -j REJECT Which explanation best describes the impact of the resulting firewall ruleset?

1. Individuals on remote networks will no longer be able to use SSH to control internal network resources.
2. Internal hosts will not be able to ping each other using ICMP.
3. Stateful multi-layer inspection has been enabled.
4. Individuals on remote networks will not be able to use ping to troubleshoot connections.

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23 A new server has been placed on the network. You have been assigned to protect this server using a packet-filtering firewall. To comply with this request, you have enabled the following ruleset:

Which choice describes the next step to take now that this ruleset has been enabled?

1. From the internal network, use your Web browser to determine whether all internal users can access the Web server.
2. From the internal network, use your e-mail client to determine whether all internal users can access the e-mail server.
3. From the external network, use your Web browser to determine whether all external users can access the Web server.
4. From the external network, use your e-mail client to determine whether all external users can access the e-mail server.

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Which of the following can help you authoritatively trace a network flooding attack?

1. Your ISP
2. Firewall logs
3. Router logs
4. Ping