1. At what layer in the TCP/IP protocol hierarchy could a firewall be placed to filter incoming traffic by means of a. Message content b. Source address c. Type of application 2. Suppose you wanted to...

1.
At what layer in the TCP/IP protocol hierarchy could a firewall be placed to filter incoming traffic by means of

a. Message content

b. Source address

c. Type of application

2.
Suppose you wanted to establish a firewall to filter out email messages containing certain terms and phrases. Would this firewall be placed at your domain’s gateway or at the domain’s mail server? Explain your answer.