EIGRP COPY COPY Flashcards
What are the 3 table in EIGRP
What IP Protocol does EIGRP use?
88 EIGRP
Reliable Transport Protocol
What does a EIGRP Hello Packet contain?
- Autonomous System # (two separate EIGRP Process will not share routes, you would need to redistribute routes).
- Hold down timer (does not have to match between router)
- Authentication
- Metric Weightings (K Values)
What address are EIGRP updates sent to?
224.0.0.10 ro unicast directly to neighbor
What best path Algrithum does EIGRP use?
DUAL creats a metric value.
What is Split Horizon?
Don’t advertise routes out the link they came in on
What is Quary?
To ask adjacent neighbors for a topology update.
DUAL Feasibility condition
- Finds loop free backup routes
- AD < FD, Path is loop-free and closer to destination. viable backup
Successor?
Best path to a destination (route)
It will be added to the routing table
Feasible Distance (FD)
Composite metric of best path (Metric)(Metric you advertise)
The total distance to the destination.
Feasible Successor (FS)
Backup Path to a destination
Advertised Distance (AD)
Composite metric learned from neighbor (Metric)(Metric you receive)
How far the destination is away for your neighbor.
Local Distance (LD)
Composite metric to reach local neighbor
ID the Successor and Feasible Successor paths.
The EIGRP Metric consist of 4 criteria. What are they
- Bandwidth (default)
- Delay (Default)
- Load
- Reliability
Name the 5 different packets that EIGRP uses.
- Hello Used for neighbor discovery
- Update Packets have routing information and are sent to router that requier this it.
- Query When a EIGRP router has lost information about a certain does not have a backup path
- Reply Used to reply to a Query packet
- ACK acknowledge the receipt of update, query, and reply packet
Name 6 things that could go wrong when forming a EIGRP neighbor adjacency.
Uncommon subnet: EIGRP neighbors with IP addresses that are not in the same subnet.
K value mismatch: By default bandwidth and delay are enabled for the metric calculation. We can enable load and reliability as well but we have to do it on all EIGRP routers.
AS mismatch: The autonomous system number has to match on both EIGRP routers in order to form a neighbor adjacency.
Layer 2 issues: EIGRP works on layer 3 of the OSI-model. If layer 1 and 2 are not working properly we’ll have issues with forming a neighbor adjacency.
Access-list issues: It’s possible that someone created an access-list that filters out multicast traffic. EIGRP by default uses 224.0.0.10 to communicate with other EIGRP neighbors.
NBMA: Non Broadcast Multi Access networks like frame-relay will not allow broadcast or multicast traffic by default. This can prevent EIGRP from forming EIGRP neighbor adjacencies.
What is a Uncommon Subnet Error?
What is a K-Value Mismatch Rule?
What is the EIGRP AS Mismatch Error?
What is the passive interface errror.
What security measure could prevent neighbor adjacency from forming?
How could a NBMA network effect Neighbor Adjacency?
