IPv4 Basics Flashcards
What is the formula for calculating the number of useable subnets under a major address as well as the formula for calculating the number of useable hosts on each subnet?
2n - 2
A Floating Static route is a static route whose _______ ________ has been increased in order to make the route function as a backup route.
A Floating Static route is a static route whose administrative distance has been increased in order to make the route function as a backup route.
Backup Interface is a Cisco feature that can be used in place of _____ _____ _____ for failover designs.
Backup Interface is a Cisco feature that can be used in place of floating static routes for failover designs.
On a Cisco Router, what would the command be to make the electrical port the backup to the fiber port in interface configuration mode?
On a Cisco Router, what would the command be to make the electrical port the backup to the fiber port in interface configuration mode?
R1(config-if)# media-type sfp auto-failover
This would make the fiber port primary. if you used media-type RJ-45 auto-failover, the electrical port would failover to the fiber port.
What does the command no media-type do on a fiber / electrical combo port?
It enables Auto-detect for the combo port.
Cisco IP SLA uses active ______ _______ for measuring traffic performance.
Cisco IP SLA uses active traffic monitoring for measuring traffic performance.
IP SLA works by generating traffic in a continuous, reliable, and predictable manner and ________ the results.
IP SLA works by generating traffic in a continuous, reliable, and predictable manner and analyzing the results.
For more advanced measurements with IP SLA, you must set up an IP SLA _______ which is an agent embedded only in Cisco devices.
For more advanced measurements with IP SLA, you must set up an IP SLA Responder which is an agent embedded only in Cisco devices.
After configuring an IP SLA Operation, you must make sure you ________ the oepration.
After configuring an IP SLA Operation, you must make sure you schedule the oepration.
Enhanced ________ _________ is a sort of glue that binds the tracking of object with upper layer protocols such as HSRP.
Enhanced Object Tracking is a sort of glue that binds the tracking of object with upper layer protocols such as HSRP.
Enhanced Object Tracking provides complete separation between the objects to be tracked and the ______ to be taken by a client when a tracked object changes.
Enhanced Object Tracking provides complete separation between the objects to be tracked and the action to be taken by a client when a tracked object changes.
What are the two aspects of an IP SLA operation that can be tracked?
What are the two aspects of an IP SLA operation that can be tracked?
- state
- reachability
The difference between IP SLA state and reachability is that reachability has the __________ return code.
The difference between IP SLA state and reachability is that reachability has the OverThreshold return code.
With Enhanced Object Tracking, the ______ option specifies a period of time to delay communicating state changes of a tracked object.
With Enhanced Object Tracking, the delay option specifies a period of time to delay communicating state changes of a tracked object.
To set up an Enhanced Object Tracking, the command in global configuration mode is ________.
To set up an Enhanced Object Tracking, the command in global configuration mode is track.
The only difference with ICMP echo operation between state and reachability is that reachability also ensures that the latency is less than _______ms.
The only difference with ICMP echo operation between state and reachability is that reachability also ensures that the latency is less than 5000 ms.
Policy-based routing can be used to change the _______ _____ _______ for traffic matching certain criteria.
Policy-based routing can be used to change the next-hop IP address for traffic matching certain criteria.
What are the two configuration elements to implement policy routing?
What are the two configuration elements to implement policy routing?
- access list (standard or extended)
- route map
How would you turn on debugging for policy routing?
How would you turn on debugging for policy routing?
debug ip policy
Where do you activate an ip policy and what is the command and parameter syntax?
Where do you activate an ip policy and what is the command and parameter syntax?
You activate an ip policy on an interface. The command is ip policy route-map <route-map></route-map>.
To apply policy based routing to traffic that is originated by a router, you must use ______ _______ ______.
To apply policy based routing to traffic that is originated by a router, you must use Local Policy Routing.
There can only be _____ ip policy per interface.
There can only be one ip policy per interface.
Since there can only be one ip policy per interface, if you need to perform multiple actions you must use a ____ _____ with multiple sections.
Since there can only be one ip policy per interface, if you need to perform multiple actions you must use a route map with multiple sections.
What command would you use to see how many packets matched an IP Policy?
What command would you use to see how many packets matched an IP Policy?
show route-map
The stats show up on the route map, not under the ip policy!
With policy routing route map configuration, what is the difference if you use the default keyword in the set ip next-hop statement?
When you do not use the default keyword, routing utilizes PBR first and consults the routing table if there is no match or non reachability. If you do use the default keyword, then routing utilizes the routing table first and consults PBR only if no route can be found.
When is the recursive keyword used in the set ip next-hop command of a route map?
Both the set ip next-hop and the set ip default next-hop commands require that the next-hop be found on a directly-connected subnet, otherwise PBR will fail and normal forwarding will be used. However, we can use set ip next-hop recursive to use an address off a subnet that is not directly connected.
What are the two ways to use set ip next-hop verify-availability?
- If used solely by itself, set ip next-hop verify-availability will use CDP to verify reachability of the next-hop address specified.
- It can be used in combination with Enhanced Object Tracking for deeper testing.
Can you list the 7 order of operations of Policy Routing?
- set ip next-hop verify-availability track - first when used with object tracking
- set ip next-hop - alone or with the CDP (but without default) version of verify-availability
- set ip next-hop recursive
- set interface
- Route table
- set ip default next-hop
- set default interface
Policy-based routing is a process whereby the device puts packets through a ____ ____ before routing them.
Policy-based routing is a process whereby the device puts packets through a route map before routing them.
The ip policy route-map command disables ____ switching of all packets arriving on the interface to which it is applied.
The ip policy route-map command disables fast switching of all packets arriving on the interface to which it is applied.
_____ ______ are not used in route maps for Policy Routing.
Prefix Lists are not used in route maps for Policy Routing.
How does Local Policy Routing differ from Policy Routing?
Local Policy Routing applies to traffic that is originated from the router, while regular Policy Routing applies to traffic that is passing through a router.
In which mode is Local Policy Routing enabled?
In which mode is Local Policy Routing enabled?
Global Configuration Mode.
A GRE Tunnel encapsulates IP packets inside GRE packets, making the connection resemble a _____________ connection.
A GRE Tunnel encapsulates IP packets inside GRE packets, making the connection resemble a point-to-point connection.
What are the three elements we must add to the Tunnel during Tunnel interface configuration?
What are the three elements we must add to the Tunnel during Tunnel interface configuration?
- Tunnel Source
- Tunnel Destination
- Tunnel IP Address
When you create a tunnel interface on a Cisco router, what is the default Tunnel Encapsulation?
When you create a tunnel interface on a Cisco router, what is the default Tunnel Encapsulation?
GRE
Why would you use keepalives on a GRE tunnel interface?
By default, the state of a point-to-point GRE interface is determined by routing availability for the tunnel destination, thus as long as the router has a route for the tunnel destination, the tunnel interface state will be UP. The keepalive will ensure there are no transit issues that would give a false UP.
In the configuration of a keepalive on a GRE tunnel, what does the interval define?
keepalive <interval> <number_of_retries></number_of_retries></interval>
The interval is the frequency in seconds for sending keepalive packets.
In the configuration of a keepalive on a GRE tunnel, what does the number of retries define?
keepalive <interval> <number_of_retries></number_of_retries></interval>
The number of retries defines the maximum number of keepalives being sent after the first failed keepalive, before the router changes the tunnel state to DOWN.
