CCNP Enarsi Flashcards
IPv6: RA Guard
Protects against rogue Router Advertisements (RA).
IPv6: DHCPv6 Guard
Protects against rogue DHCPv6 servers.
IPv6: Source Guard
Prevents IPv6 address spoofing by validating source addresses.
IPv6: Prefix Guard
Blocks the advertisement of unauthorized IPv6 prefixes.
IPv6: NA Guard
Protects against rogue Neighbor Advertisements (NA).
IPv4: DHCPDISCOVER
Sent by the client to locate available DHCP servers.
IPv4: DHCPOFFER
Sent by the DHCP server in response to a DHCPDISCOVER offering an IP lease.
IPv4: DHCPREQUEST
Sent by the client to request an offered IP or renew an existing lease.
DHCPACKIPv4:
Sent by the server to acknowledge the client’s DHCPREQUEST and finalize the IP lease.
IPv4: DHCPNAK
Sent by the server if the requested IP address is invalid or cannot be assigned.
IPv4: DHCPDECLINE
Sent by the client if the offered IP address is already in use.
IPv4: DHCPRELEASE
Sent by the client to release the assigned IP address back to the server.
IPv4: DHCPINFORM
Sent by the client to request additional configuration without obtaining an IP address.
IPv6: SOLICIT
Sent by the client to discover available DHCPv6 servers.
IPv6: ADVERTISE
Sent by the DHCPv6 server in response to a SOLICIT advertising its availability.
IPv6: REQUEST
Sent by the client to request configuration or IP from the DHCPv6 server.
IPv6: REPLY
Sent by the server in response to a REQUEST confirming the IP lease or providing configuration data.
IPv6: RENEW
Sent by the client to renew a current lease before it expires.
IPv6: REBIND
Sent by the client to extend an expiring lease if the original server is unreachable.
IPv6: DECLINE
Sent by the client to reject an IP address that is already in use.
IPv6: RELEASE
Sent by the client to release an assigned IP address.
IPv6: CONFIRM
Sent by the client to confirm the validity of a previously assigned IP address.
IPv6: INFORMATION-REQUEST
Sent by the client to request configuration information without an IP address.
uRPF: Strict Mode
Checks if the source address of the packet has a valid route through the same interface it was received on.
“ip verify unicast source reachable-via rx”
uRPF: Loose Mode
Checks if the source address has a valid route in the routing table regardless of the incoming interface.
“ip verify unicast source reachable-via any”
uRPF: VRF Mode
Used in Virtual Routing and Forwarding (VRF) environments to check routes within a specific VRF instance.
“ip vrf forwarding VRF1
ip verify unicast source reachable-via rx”
uRPF: Feasible Mode
Allows the packet if the source IP address has a valid route in the routing table or a feasible successor route in EIGRP.
“ip verify unicast source reachable-via rx
router eigrp 100
network 192.168.1.1”
UDP Port: 1812
Default port for RADIUS authentication.
UDP Port: 1813
Default port for RADIUS accounting.
DNA Center: Overall Health Score
Represents the overall health of the network and devices based on various metrics.
DNA Center: Device Health Score
Reflects the operational state of individual devices in the network.
DNA Center: Application Health Score
Indicates the performance and availability of applications running in the network.
DNA Center: Network Health Score
Measures the overall health of the network infrastructure including connectivity and performance.
DNA Center: Wireless Health Score
Evaluates the performance and coverage of wireless networks including APs and clients.
DNA Center: Client Health Score
Assesses the connectivity and performance of individual clients connected to the network.
DNA Center: Security Health Score
Indicates the security posture of the network including compliance and threat detection.
IPv6: Neighbor Solicitation (NS)
Used by a node to determine the link-layer address of a neighbor or to verify the reachability of a neighbor.
IPv6: Neighbor Advertisement (NA)
Sent by a node in response to a Neighbor Solicitation or to announce its link-layer address change.
IPv6: Router Solicitation (RS)
Sent by a host to discover available routers on the network.
IPv6: Router Advertisement (RA)
Sent by routers to provide information about network prefixes parameters and their own link-layer addresses.
IPv6: Redirect Message
Used to inform a host of a better first-hop address for a destination than the one it is currently using.
OSPF: Backbone Area (Area 0)
The core area that connects all other OSPF areas.,Type 1, Type 2, Type 3, Type 4, Type 5
OSPF: Standard Area
An area that can contain any type of LSA and can communicate with other areas.,Type 1, Type 2, Type 3, Type 4, Type 5
OSPF: Stub Area
An area that does not receive external routes (Type 5 LSAs) and uses a default route for external networks.,Type 1, Type 2, Type 3, Type 4
OSPF: Totally Stubby Area
Similar to a stub area, but does not receive summary routes (Type 3 and Type 4 LSAs) or external routes.,Type 1, Type 2
OSPF: Not-So-Stubby Area (NSSA)
Allows the injection of external routes while still restricting other external route advertisements.,Type 1, Type 2, Type 3, Type 7
LDP: Label Mapping
Used to associate a label with a specific FEC (Forwarding Equivalence Class) for label switching.
LDP: Label Withdrawal
Sent to withdraw a previously assigned label from a specific FEC.
LDP: Label Release
Used to release a label that is no longer needed typically in response to a Label Withdrawal.
LDP: Label Request
Sent by a LSR (Label Switching Router) to request a label for a specific FEC from its peers.
LDP: Label Notify
Used to inform a peer of a label change for a specific FEC.
LDP: Hello
Used to discover and maintain neighbor relationships between LSRs.
Log level: 0
(Emergency) System is unusable; indicates a serious failure.
Log level: 1
(Alert)Immediate action needed; alerts that require immediate attention.
Log level: 2
(Critical) Critical conditions; indicates a failure in a primary system component.
Log level: 3
(Error)Error conditions; indicates an error that has occurred.
Log level: 4
(Warning) Warning conditions; indicates a warning about a potential problem.
Log level: 5
(Notice)Normal but significant conditions; used for important events that are not errors.
Log level: 6
(Informational) Informational messages; used for normal operational messages.
Log level: 7
(Debug) Debugging messages; used for diagnostic information primarily for troubleshooting.