QUESTIONS OF CYBER SECURITY WITH PRECISE ANSWERS#2
What port does ping work over? - correct answer it doesn't. Ping is icmp, which is layer 3. Ports
are not used until layer 4 which handles udp and tcp.
What osi layer does a router work at? - correct answer the network layer, which is the layer
that handles switching, routing, and addressing.
Describe layer 1 of the osi model - correct answer physical layer
Description: holds the bit streams and electronic impulses over cables, air, or other medium
that transmits bit stream signals.
Protocols: atm
Examples: ethernet
Describe layer 2 of the osi model - correct answer data link layer
Description: responsible for encoding and decoding data packets into bits. This involves
defining packet frames and the structure of the bits streaming across the physical layer.
Protocols: ethernet frame relay, ieee 802.5, ppp
Levels:
1) mac - media access control interfaces with the network medium and gives a unique address
to the hardware on the network 2) llc - logical link control handles flow rate, synchronization of
packets, and error checking
Examples:
Describe layer 3 of the osi model - correct answer network layer
Description: provides addressing, switching, routing, internetworking, error handling and data
flow control.
Examples:
Protocols: icmp, arp, ipv4, ipv6, ipsec, bgp, ospf
, Describe layer 4 of the osi model - correct answer transport layer
Description: transfers data from end to end, ie. One host over a network or the internet to
another host.
Examples:
Protocols: udp, tcp
Describe layer 5 of the osi model - correct answer session layer
Description: establishes, manages, and terminates conversations between applications at each
end.
Protocols: smb, nsf, rpc, sql
Describe layer 6 of the osi model - correct answer presentation layer aka syntax layer
Description: provides conversion between lower layer information and the application so the
application can understand. Handles compatibility issues.
Examples: tls, mp3, ascii, tiff, jpg
Describe layer 7 of the osi mode - correct answer application layer
Description: provides services used by applications running on the host.
Examples: http, ftp, telnet, snmp, dns
Do you prefer filtered ports or closed ports on your firewall? - correct answer filtered: sends
back a response that traffic is blocked, gives away firewall presence
Closed: causes timeout, not response
Obscurity increases the attackers work by a bit. They suspect but do not know for sure that a
firewall is present. Attacker can attempt again or attempt other types of traffic. This may
increase chances of detecting 'scanning'.
What port does ping work over? - correct answer it doesn't. Ping is icmp, which is layer 3. Ports
are not used until layer 4 which handles udp and tcp.
What osi layer does a router work at? - correct answer the network layer, which is the layer
that handles switching, routing, and addressing.
Describe layer 1 of the osi model - correct answer physical layer
Description: holds the bit streams and electronic impulses over cables, air, or other medium
that transmits bit stream signals.
Protocols: atm
Examples: ethernet
Describe layer 2 of the osi model - correct answer data link layer
Description: responsible for encoding and decoding data packets into bits. This involves
defining packet frames and the structure of the bits streaming across the physical layer.
Protocols: ethernet frame relay, ieee 802.5, ppp
Levels:
1) mac - media access control interfaces with the network medium and gives a unique address
to the hardware on the network 2) llc - logical link control handles flow rate, synchronization of
packets, and error checking
Examples:
Describe layer 3 of the osi model - correct answer network layer
Description: provides addressing, switching, routing, internetworking, error handling and data
flow control.
Examples:
Protocols: icmp, arp, ipv4, ipv6, ipsec, bgp, ospf
, Describe layer 4 of the osi model - correct answer transport layer
Description: transfers data from end to end, ie. One host over a network or the internet to
another host.
Examples:
Protocols: udp, tcp
Describe layer 5 of the osi model - correct answer session layer
Description: establishes, manages, and terminates conversations between applications at each
end.
Protocols: smb, nsf, rpc, sql
Describe layer 6 of the osi model - correct answer presentation layer aka syntax layer
Description: provides conversion between lower layer information and the application so the
application can understand. Handles compatibility issues.
Examples: tls, mp3, ascii, tiff, jpg
Describe layer 7 of the osi mode - correct answer application layer
Description: provides services used by applications running on the host.
Examples: http, ftp, telnet, snmp, dns
Do you prefer filtered ports or closed ports on your firewall? - correct answer filtered: sends
back a response that traffic is blocked, gives away firewall presence
Closed: causes timeout, not response
Obscurity increases the attackers work by a bit. They suspect but do not know for sure that a
firewall is present. Attacker can attempt again or attempt other types of traffic. This may
increase chances of detecting 'scanning'.
