9.1: First Hop Redundancy Protocols Flashcards
If a router or router interface (that serves as a default gateway) fails, the hosts configured with that default gateway are ___from outside networks
isolated
The ____ mechanism is needed to provide alternate default gateways in switched networks where two or more routers are connected to the same VLANs.
first hop redundancy protocols (FHRPs)
In a switched network, how many default gateways does each client receive?
Only one
True or false
There is a way to use a secondary gateway, even if a second path exists to carry packets off the local segment.
There is no way to use a secondary gateway, even if a second path exists to carry packets off the local segment.
Even if a redundant router exists that could serve as a default gateway for that segment, there is no __method by which these devices can determine the address of a new default gateway.
dynamic
One way to prevent a single point of failure at the default gateway is to implement a ___.
virtual router
To implement this type of router redundancy, multiple routers are configured to work together to present the illusion of a ___ router to the hosts on the LAN, as shown in the figure.
single
By sharing an ___ and a ____, two or more routers can act as a single virtual router.
IP address
MAC address
ROUTER REDUNDANCY PROCESS
1. The ___of the virtual router is configured as the default gateway for the workstations on a specific IPv4 segment
IPv4 address
ROUTER REDUNDANCY PROCESS
2. When frames are sent from host devices to the default gateway, the hosts use___ to resolve the MAC address that is associated with the IPv4 address of the default gateway.
ARP
ROUTER REDUNDANCY PROCESS
3. The ARP resolution returns the ___ of the virtual router. Frames that are sent to the MAC address of the virtual router can then be physically processed by the currently active router within the virtual router group.
MAC address
ROUTER REDUNDANCY PROCESS
4. A protocol is used to identify two or more routers as the devices that are responsible for processing frames that are sent to the MAC or IP address of a__.
single virtual router
ROUTER REDUNDANCY PROCESS
5. Host devices send traffic to the address of the virtual router. The physical router that forwards this traffic is ____to the host devices.
transparent
ROUTER REDUNDANCY PROCESS
6. A ___ protocol provides the mechanism for determining which router should take the active role in forwarding traffic. It also determines when the forwarding role must be taken over by a standby router. The transition from one forwarding router to another is transparent to the end devices.
redundancy
ROUTER REDUNDANCY PROCESS
The ability of a network to dynamically recover from the failure of a device acting as a default gateway is known as ___.
first-hop redundancy
STEPS FOR ROUTER FAILOVER
When the active router fails, the redundancy protocol transitions the ____router to the new active router role
standby
STEPS FOR ROUTER FAILOVER
1. The standby router stops seeing ___ messages from the forwarding router.
Hello
STEPS FOR ROUTER FAILOVER
2. The standby router assumes the role of the ___ router.
forwarding
STEPS FOR ROUTER FAILOVER
3. Because the new forwarding router assumes both the ___ of the virtual router, the host devices see no disruption in service.
IPv4 and MAC addresses
FHRP OPTIONS
___is a Cisco-proprietary FHRP that is designed to allow for transparent failover of a first-hop IPv4 device.
Hot Standby Router Protocol (HSRP)
FHRP OPTIONS
____provides high network availability by providing first-hop routing redundancy for IPv4 hosts on networks configured with an IPv4 default gateway address.
Hot Standby Router Protocol (HSRP)
FHRP OPTIONS
HSRP is used in a group of routers for selecting an ___
active device and a standby device
In a group of device interfaces, the ___ is the device that is used for routing packets
active device
In a group of device interfaces, the __ is the device that takes over when the active device fails, or when pre-set conditions are met.
standby device
The function of the HSRP standby router is to monitor the operational status of the HSRP group and to quickly assume ___responsibility if the active router fails.
packet-forwarding
FHRP OPTIONS
This is a Cisco-proprietary FHRP that provides the same functionality of HSRP, but in an IPv6 environment.
Hot Standby Router Protocol (HSRP) for IPv6
FHRP OPTIONS
An HSRP IPv6 group has a virtual MAC address derived from the __and a virtual IPv6 link-local address derived from the_____
HSRP group number
HSRP virtual MAC address
FHRP OPTIONS
Periodic ___are sent for the HSRP virtual IPv6 link-local address when the HSRP group is active.
router advertisements (RAs)
HSRP for IPv6: When the group becomes inactive, these RAs stop after a ___.
final RA is sent
FHRP OPTIONS
This is a non-proprietary election protocol that dynamically assigns responsibility for one or more virtual routers to the VRRP routers on an IPv4 LAN.
Virtual Router Redundancy Protocol version 2 (VRRPv2)
FHRP OPTIONS
This provides the capability to support IPv4 and IPv6 addresses. This works in multi-vendor environments and is more scalable than VRRPv2.
Virtual Router Redundancy Protocol version 3 (VRRPv3)
FHRP OPTIONS
This is a Cisco-proprietary FHRP that protects data traffic from a failed router or circuit, like HSRP and VRRP, while also allowing load balancing (also called load sharing) between a group of redundant routers.
Gateway Load Balancing Protocol (GLBP)
FHRP OPTIONS
This is a Cisco-proprietary FHRP that provides the same functionality of GLBP, but in an IPv6 environment.
Gateway Load Balancing Protocol (GLBP) for IPv6
FHRP OPTIONS
____ provides automatic router backup for IPv6 hosts configured with a single default gateway on a LAN.
GLBP for IPv6
FHRP OPTIONS
GLBP for IPv6: Multiple first-hop routers on the LAN combine to offer a single virtual first-hop IPv6 router while sharing the ___.
IPv6 packet forwarding load
FHRP OPTIONS
Specified in RFC 1256, ___ is a legacy FHRP solution
ICMP Router Discovery Protocol (IRDP)
FHRP OPTIONS
___ allows IPv4 hosts to locate routers that provide IPv4 connectivity to other (nonlocal) IP networks.
ICMP Router Discovery Protocol (IRDP)
FHRP OPTIONS
___ allows IPv4 hosts to locate routers that provide IPv4 connectivity to other (nonlocal) IP networks.
ICMP Router Discovery Protocol (IRDP)