EIGRP Flashcards
When does EIGRP send full and partial updates?
Full on neighbor adjacency
Partial as needed when network topology changes
What are the 2 primary timers for EIGRP?
Hello
Hold
What are the default values for the Hello and Hold timers in EIGRP?
Hello = 5 seconds Hold = 3xHello, or 15 seconds by default
What are EIGRP’s 2 primary metrics?
Bandwidth and Delay
What is the multicast address for EIGRP?
224.0.0.10
Does EIGRP ever flood updates periodically?
No, only during adjacency setup or topology changes
What are the 3 required and 1 optional attributes that must pass before an EIGRP adjacency will be established?
Required:
- Same AS number
- Same IP subnet
- Matching K values
Optional:1. Authentication, if configured, must match.
What is the Feasible Distance in EIGRP?
The metric of an EIGRP route on the local router.
What is the Reported Distance in EIGRP?
The next-hop router’s best metric for a FD subnet
What algorithm is used by EIGRP
DUAL
What does DUAL stand for?
Diffusing Update ALgorithm
Does the EIGRP ASN need to match between neighbors?
Yes
Syntax to include interfaces into EIGRP
conf t
router eigrp ASN
network network [wildcard mask]
What 3 attributes must match for EIGRP neighbors to become adjacent?
- Same subnet
- Same ASN
- Matching K-values
What is the all-EIGRP routers IPv6 address?
FF02::10
What are the EIGRP k values, in order?
K1 = Bandwidth modifier K2 = Load modifier K3 = Delay modifier K4 = Reliability modifier K5 = Additional Reliability modifier
2 steps to have EIGRP use a key chain in authentication
- Under a given interface, set up authentication for the routing protocol.
- Staying under that same interface, bind the key-chain that will be used to the auth line.
Syntax to bind a key chain to EIGRP authentication
conf t
int gi1/0
ip authentication key-chain eigrp asn key-chain name
Syntax to add automatic summarization to EIGRP
auto-summary
Change the bandwidth or delay on an interface for EIGRP
conf t
int gi1/0
bandwidth value
delay value
Syntax to set the hello and hold timers for EIGRP
conf t
int gi1/0
ip eigrp hello-interval seconds
ip eigrp hold-time seconds
Configuration to allow for unequal cost load balancing in EIGRP
variance multiplier
When you show the routing table, what letter signifies that route was learned via EIGRP?
D
Syntax to set up authentication for eigrp under an interface.
conf t
int gi1/0
ip authentication mode eigrp asn md5
What is the successor?
The successor is the path that has the best metric.
What is the Feasible Distance?
The metric of a given route from the current router’s point of view.
What is the Reported Distance?
The metric of a given route from the neighbor’s point of view.
If a path meets the feasibility condition, but does not fall within variance parameters, what happens to it?
It is held in reserve as a feasible successor, one which may take over if the current successor fails.
What is the feasibility condition?
The reported distance of a path must be less than the FD of the path on the current router.
What happens to a path who’s FD falls within variance parameters but does not meet the feasibility condition?
It’s not installed in the routing table, nor will it be a Feasible Successor
How does a router determine if a path can be a Feasible Successor?
If the path’s RD is less that the FD, it will be a Feasible Successor.
