Ayda Test 1 Flashcards
where can you configure firewalls?
device
virtual appliance
software component of an OS
software component on a network device (eg router)
A firewall Permits desirable traffic to be transported between what?
untrusted network/host to a trusted network/host
What does a firewall execute to permit and/or prevent network traffic?
it executes rules
A firewall prevents ______ ________ from being transported from an untrusted network/host to a trusted network/host
harmful traffic
Stateless Packet filtering filters which layers of traffic?
Layer 3 protocols (standard)
Layer 3 and layer 4 protocols (extended)
Stateless packet filtering can filter which two ports?
Can filter UDP and TCP ports?
Firewall Rules may control traffic based on/ applied that what?
Interface
Direction-inbound/outbound
IP addresses
Port addresses
What are potential issues with firewall rules?
Erroneous rule configuration
Non-removal of stale rules
Excessively permissive
Excessively restrictive
Determine placement of firewall(s) to ______ networks and hosts of different trust levels. Include physical security
segregate
Packet Filtering Firewall Fundamental rules govern traffic transport based on what?
Permit or deny Source and/or destination IP address Source and/or destination ports Layer 4 protocol Direction (inbound/outbound)
On Cisco devices Packet Filtering is Implemented as _______ _______ ________
Access Control Entries (ACEs)
AccessAccess Control Entries (ACEs) are implemented within _________ ____________ ________
Access Control Lists (ACLs)
Standard ACLs inspects only source _______ _______
Standard inspects only source IP address
Extended ACLs inspects ______ and _______ L3 and L4 addresses plus L4 protocols
source and destination
Packet Filtering Rules are processed in order from ????
top to bottom
Access lists are attached to whatt?
interfaces
To reduce the load on the firewall inbound rules process prior to what?
routing processes
Outbound rules are processed after what?
after routing process
Can often simplify multiple inbound ACLs by
a single outbound ACL
NAT translates L3 addreses between?
interfaces
Changes source IP on _______ packets and destination IP on _____ packets
Changes source IP on outbound packets and destination IP on inbound packets
What are the three types of NAT?
- Static
- dynamic
- Overloading (Port address translation)
What type of NAT manually maps a private IP to public?
Static Nat
What type of NAT Automatically map private IP to public IP? Typically using a pool of available ip addresses.
Dynamic NAT
What type of NAT automatically map many private IPs to one public IP?
Overloading | PAT
Uses ports to track individuals from many
Inside local addresses are?
Actual IP address assigned to an inside host
Typically private
Inside global addresses are?
Outside view IP address of inside host after translation
Typically address of router connected to ISP
Outside local addresses are?
Inside view IP address of outside host after translation Only when NAT from outside to inside
Outside global addressed are?
Actual IP address assigned to outside host
NAT processed from inside to outside or vice versa
How do you configure the interfaces?
inside or outside
ed: ip nat inside
ip nat outside
Interfaces have security levels which reduce need for?
ACLs
Zone based firewall is contextual firewall allowing logical application of security policy through groups of ?
interfaces
Zone based firewall features?
Application inspection (not new but easier to configure)
URL filtering
Transparent firewall (bridged rather than routed)
Supports Virtual Routing and Forwarding (VRF)
A Zone is object consisting of one or more?
interfaces
May be physical or virtual
Traffic between zones are _______ by default
blocked
Zones are easily modified by adding/removing?
interfaces
A ______ ______ is an object consisting of two or more zones
Zone pair
What are the steps in creating zone based firewall?
Create zones Map interfaces to zones Create zone pairs Create class maps Create policy maps Apply policy maps to zone pairs with service policies
What is ASA?
Adaptive Security Appliance
What command is used to see real live NAT translation occurring on the router? show ip nat translation debug ip nat clear ip nat translations * show ip nat statistics
debug ip nat
What command is used to clear all translations on the router? show ip nat translation debug ip nat clear ip nat translations * show ip nat statistics
clear ip nat translations *
What command is used to show the summary of NAT configuration? show ip nat translation debug ip nat clear ip nat translations * show ip nat statistics
show ip nat statistics
