Cisco Learning Note CCNP-EIGRP

Eigrp

Cisco Private Protocol (already public)

Multicast address 224.0.0.10

Characteristics:

Advanced Distance vectors (topology table)

Fast Convergence (fastest in small networks)

100% Loop-Free

Simple configuration

Easy to update

Flexible network design

Multicast update replaces broadcast update

Supports VLSM and discontinuous subnets

Support manual aggregation anywhere on the network

Supports multiple network layer protocols

Supports equivalent and non-equivalent load balancing (unique)

Three sheets:

Neighbor table ensures two-way communication between neighbors

Topology table stores all routes to the destination address, listing all routes learned from the neighbor table

Routing Table Select the best route from the topology table into the routing table

Conditions for becoming a feasible successor (feasible successor):

FD of Best route > AD's Second best route

ad:advertised distance (notice distance)

Fd:feasible Distance = EIGRP Metric (feasible distance)

Feasible successor condition (FC feasible condition)

FS: ad for optimal routing of FD > suboptimal routes

Conditions of successor:

The FD is the smallest in the route

Rtp:reliable Transport protocol Reliable Transmission Protocol

Qos:real Time Transport Protocol

Group:

Hello for Neighbor Discovery and maintenance multicost

Update delivery path is updated with only the required entries, and when sending updates for a router, use unicast when sending updates for multiple routes using multicast

Query when FS is not found, send inquiry message, multicast

Reply response Query message, multicast

ACK is used to confirm update/query/reply, unicast.

Hello packet send time interval:

Bandwidth > 1.544m Hello time INTERVL 5s

=< Hello time INTERVL 60s

Same k value, same password verification

Hello pack:

When two routes receive Hello packets from each other, they can form neighbors

K-value matching, as, authentication

Establish the order of the Neighbors:

Addresses used by address neighbors

Interface

Hold time hold time is 3 times times the relationship with Hello time

Uptime how long the relationship was established with the neighbor (the time the Reply/update/query received the ACK)

SRTT Ms average round trip time timer

RTO retransmission timer, RTO is two retransmission interval when route update is not received ACK will be re-transmitted

Q Cut Queue--see value not equal to 0 is not normal

SEQ Num Serial Number

Hello-time and hold-time for different times, hello-time less than Hold-time will not have an effect

EIGRP's retransmission limit is 16 times

Reasons for EIGRP Reset:

1.hold Time Timeout

2.16 Re-transmission

3.SIA

Eigrp metric=256* (IGRP Metric) (256=8bit)

k1= bandwidth Bandwitch (minimum bandwidth between source and destination)

k2= load loading (maximum load between source and destination)

k3= latency Delay (sum of delay between source and destination)

k4= Reliability Reliability (minimum reliability between source and destination)

K5=MTU (minimum MTU between source and destination)

Eigrp Metric =256* (10^7/BW+DLY/10)---------------------------BW Unit is K

BW (min)/dly (sum)

Delay is the sum of the delay of the incoming interface in the direction of the route, and there is also a delay in the loopback port

Change Bandwidth Router (config-if) #bandwidth  

Change the delay Router (config-if) #delay-----------------------------------------The value entered by default *10

ad--metric of the arrival purpose of the neighbor's notice

fd--metric of the destination of this router

successor--routes with the best metric values

Feasible successor--a fallback route that meets FC conditions

Dual dispersion correction algorithm:

If the successor router is not found, the feasible successor router will be used

If a valid successor router is not found, all neighbors will be queried for subsequent routers

SIA stuck in active card in active state

If the SIA status exceeds 3 minutes, the neighbor relationship is reset

  

Show IP EIGRP Interfaces View those interfaces are declared into EIGRP

EIGRP has a default route issued (4 types):

On the boundary route, write a default route to the public network, router EIGRP network 0.0.0.0 0.0.0.0

Write a default route redistribute static (heavy division)

Write IP summary-address Eigrp 90 0.0.0.0 on the interface 0.0.0.0

Ip default-network 23.0.0.0 Router Eigrp network 23.0.0.0

EIGRP Route Rollup:

Pros: Smaller routing tables, smaller update and query boundaries

Auto Rollup: Automatic summarization occurs by default when the cluster network

Characteristics:

1. You can manually create summary routes anywhere on the network (you must have detailed routing)

2. After a rollup is configured on the router interface, the router generates a pointer to the NULL0 route, and the Loop prevention mechanism

3. If the router receives a packet and goes to a subnet in the summary range, the router will follow the longest matching rule

4.EIGRP Summary route Management distance is 5

The EIGRP rollup route generates a rollup route on itself that points to the Null0 port, and the administrative distance is 5.

EIGRP Passive Interface Router (config-router) #passive-interface loopback (must be in process)

Interface cannot send and receive Hello packets, but this interface is still declared in EIGRP

* For ring-back ports, other routers can still

*neighbors cannot be used in EIGRP, use no effect

Under process, Metric maximum-hops 255 is 100 by default and can be modified to 255

Load balancing is the ability of a router to allocate traffic on a network port that has the same distance from its destination address

EIGRP supports unequal-price load balancing

Variance is a companion factor that controls the range of measures that participate in a load-balanced path, and only the feasible path is used for load balancing.

Router (config-router) #variance 2 default EIGRP only supports equivalent load balancing

FS ' s FD < V * successor's FD U value determined by itself (1-128)

The premise is that this route must first become feasible succasor, otherwise it will not be used for load balancing

Maximum-paths 16

Ip bandwidth-percent eigrp (bw*200%)

If the router does not receive a response to the query within 3 minutes (the default time), the route will be in an active state

Limiting the range of queries in the network can help reduce the probability of the occurrence of Sia

Using Totals to limit query scope

Use stub routers to limit query scope

Use routing totals to reduce query messages

Load Balancing:

Change bandwidth and latency

Modify offset displacement

EIGRP stub "Receive only | Connected | Static |summary "

EIGRP stub routers send special peer information groupings to all of their picking routers, indicating that they are a stub router.

After a neighbor receives a packet indicating the stub status, it does not want the stub router to query any routes

Eigrp stub transmits connected and summary without any parameters

Common causes of Sia:

Query scope is too large

The router is too busy to answer the query

Poor link quality between routers, resulting in the loss of query packets.

Some unidirectional links fail

Router (config-router) #timer actve-time [2 | disable]

(SiA timer, default is 3 minutes, more than 3 minutes is to reset the neighbor relationship, to avoid the card in the active state)

Sia-query at half of the normal active timer Router B acknowledges the Query there by keeping the relationship up

  

EIGRP BGP only supports MD5, EIGRP uses update to carry encrypted information  

EIGRP Authentication

Key ID sent from small to large, as long as there is a small key ID exists, and legal, the large ID will not be sent, the following verification is unsuccessful.

Cisco Learning Note CCNP-EIGRP