1. EIGRP packetlife.net
Protocol Header Attributes
8 16 24 32 Type Distance Vector
Version Opcode Checksum
Algorithm DUAL
Flags
Internal AD 90
Sequence Number
External AD 170
Acknowledgment Number
Summary AD 5
Autonomous System Number
Standard Cisco proprietary
Type Length
Protocols IP, IPX, Appletalk
Value
Transport IP/88
Metric Formula Authentication MD5
K2 * bw K5 Multicast IP 224.0.0.10
256 * (K1 * bw + + K3 * delay) *
256 - load rel + K4 Hello Timers 5/60
· bw = 107 / minimum path bandwidth in kbps Hold Timers 15/180
· delay = interface delay in µsecs / 10
K Defaults Packet Types
EIGRP Configuration
K1 1 1 Update
Protocol Configuration
K2 0 3 Query
! Enable EIGRP
router eigrp <ASN> K3 1 4 Reply
! Add networks to advertise K4 0 5 Hello
network <IP address> <wildcard mask>
K5 0 8 Acknowledge
! Configure K values to manipulate metric formula
metric weights 0 <k1> <k2> <k3> <k4> <k5>
Terminology
Reported Distance
! Disable automatic route summarization The metric for a route advertised by a neighbor
no auto-summary
Feasible Distance
! Designate passive interfaces The distance advertised by a neighbor plus the cost
passive-interface (<interface> | default) to get to that neighbor
Stuck In Active (SIA)
! Enable stub routing
The condition when a route becomes unreachable
eigrp stub [receive-only | connected | static | summary]
and not all queries for it are answered; adjacencies
! Statically identify neighoring routers with unresponsive neighbors are reset
neighbor <IP address> <interface> Passive Interface
An interface which does not participate in EIGRP but
Interface Configuration whose network is advertised
! Set maximum bandwidth EIGRP can consume
ip bandwidth-percent eigrp <AS> <percentage>
Stub Router
A router which advertises only a subset of routes,
! Configure manual summarization of outbound routes and is omitted from the route query process
ip summary-address eigrp <AS> <IP address> <mask> [<AD>]
Troubleshooting
! Enable MD5 authentication show ip eigrp interfaces
ip authentication mode eigrp <AS> md5
ip authentication key-chain eigrp <AS> <key-chain> show ip eigrp neighbors
! Configure hello and hold timers show ip eigrp topology
ip hello-interval eigrp <AS> <seconds> show ip eigrp traffic
ip hold-time eigrp <AS> <seconds>
clear ip eigrp neighbors
! Disable split horizon for EIGRP
no ip split-horizon eigrp <AS> debug ip eigrp [packet | neighbors]
by Jeremy Stretch v2.1