Firewalls Flashcards
What two pieces of hardware make up the hardware half of a firewall?
1) a router
2) A blackbox with two NICs
What 5 things can firewalls do with traffic?
1) permit
2) deny
3) encrypt
4) decrypt
5) proxy
ACLs are first line of defence for a network that is connected to the internet - TRUE or FALSE?
TRUE
1) inbound and outbound spoofing
2) Denial of Service TCP SYN attacks
3) DoS Smurf attacks
What can be used to mitigate the above attacks?
ACLs
How can ACLs mitigate against the below 3 types of attacks?
1) inbound and outbound spoofing
2) Denial of Service TCP SYN attacks
3) DoS Smurf attacks
1) inbound and outbound spoofing - Filtering ICMP messages inbound and outbound
2) Denial of Service TCP SYN attacks - TCP intercept to address TCP Syn attacks
3) DoS Smurf attacks - Filtering Traceroute
ACLs can be used to block routing protocols - TRUE or FALSE?
TRUE
An ACL applied to protocols instead of interfaces is known as what?
Distribution List
ACLs can categorize and queue packets for applications that require QoS, TRUE or False?
True
What could you use to control traffic that may be bound for an expensive backup link?
Using an ACL
In dynamic packet filtering, what keeps track of all communicating sessions between stations?
Dynamic State List or State Table
Proxies services exchange information between the server on behalf of the host on what layer of the OSI model?
Application
What layers of the OSI model can proxies examine?
All layers
If you wanted to scan keywords in incoming and outgoing email, what type of proxy would you implement?
SMTP Proxy
IP proxies are also known as what?
NAT Proxies
What proxy can speed up web surfing?
HTTP Proxy
What type of firewall doesn’t care about whether the packet it is examining is stand-alone or part of a bigger message stream?
Stateless firewall
Stateless firewalls use less memory than stateful, but stateless firewalls can be quicker once once a new connection is established. TRUE or FALSE
TRUE
Statefull firewalls work by using the TCP 3-way handshake but can also keep track of connections using UDP. TRUE or FALSE?
TRUE
Firewalls can’t protect against SYN floods. TRUE or FALSE?
FALSE, they can
What type of firewall lets you set proxy rules for multiple applications?
Layer 7 firewall
What does dynamic packet filtering ensure and on what OSI layer does it operate?
Dynamic packet filtering ensures that the packets forwarded by firewalls match the TCP/UDP sessions initiated by stations inside the network to prevent outsiders hijacking the session. It works at the Transport layer.
