Study
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Quiz!
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define forward acknowledgment in the context of TCP |
when the ack field contains the number of the next sequence to send |
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The term __________ is sometimes used to describe the error recovery and windowing process that TCP uses |
PAR Positive Acknowledgment and Retransmission |
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MTU |
maximum transmission unit |
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What is MTU (not what it stands for) |
the largest layer 3 packet that can sit inside a frame's data field |
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What is the MTU for Ethernet |
1500 bytes |
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What is the MTU for Ethernet |
1500 bytes |
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The L4PDU is also known as a _______ |
segment |
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How can NFS use UDP if UDP doesn't perform error recovery? |
NFS performs its own error recovery at the application layer |
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Two advantages of UDP |
lower bytes of overhead does not wait for acknowledgments |
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List three QoS requirements of VoIP (and Video over IP) |
Low delay |
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VoIP requires relatively (low/high) bandwidth and (low/high) jitter compared to most network applications |
low, low |
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Typically, the client learns the DNS server's IP address via ______ |
DHCP |
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What is the HTTP return code for OK (request was successfully filled) |
200 |
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What is the HTTP return code for "file not found" |
404 |
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The firewall mainly looks at the transport layer _________ and the application layer ________ |
port numbers, headers |
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DoS "destroyer" attack |
tries to harm the hosts, erasing data and software |
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DoS "crasher" attack |
tries to cause hosts to fail or causing the machine to no longer be able to connect to the network |
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DoS "flooder" attack |
flood the network with packets to make the network unusable |
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Three ways an Enterprise with a working firewall can be attacked from within |
access from the wireless LAN |
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Cisco uses the term ________ to refer to a security design that includes security tools throughout the network, including features in routers and switches |
security in depth |
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Cisco uses the term _______ to refer to automation in which the network devices automatically react to network problems |
self-defending network |
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NAC |
Network Admission Control |
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NAC (what it does not what it stands for) |
Sets requirements for users to connect to the LAN. These can include username / password, and making sure virus definitions are up to date before allowing access |
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Definition of Port Scanner |
sends connection requests to different TCP and UDP ports, in an attempt to discover which hosts run IP services, and possibly the operating system on each host |
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Worm is most useful in which type of attack |
DoS |
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ASA stands for |
Adaptive Security Appliance |
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The DMZ LAN is a place to put devices that need to be accessible by ________ |
the outside internet |
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How is an ASA same / different from a firewall? |
ASA can function as a firewall, or in a variety or combination of security roles. |
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Cisco's pre-ASA firewalls were sold under what name? |
PIX |
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Cisco usese the term _____ to refer to the whole class of security tools that prevent various security problems |
anti-x |
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IDS and IPS |
Intrusion Detection System Intrusion Prevention System |
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_________ tools detect threats by watching for trends, looking for attacks taht use particular patterns of messages, and other factors |
IDS / IPS |
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Difference between IDS and IPS |
IDS = typically receive a copy of packets via a monitoring port IPS = sit in the packets' forwarding path. because of this, IPS is able to react to threats as they happen, making it generally more powerful than IDS (i think) |
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T/F: a leased line is inherently secure |
True |
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Two types of VPN |
access VPN site-to-site intranet VPN |
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Difference between the two types of VPN |
access VPN = connects a home or small-office user, encryption done by remote office's PC site-to-site intranet VPN = connects two sites of the same Enterprise. encryption done by various hardware |
