Static Routing and Distance Vector Routing Protocols - CCIE Routing and Switching Exam Certification Guide - page 348

Table 7-3 shows some default values for bandwidth and delay.

Default EIGRP Values for Bandwidth and Delay

Table 7-3

Media Type Delay Bandwidth

Satellite 5120 (2 seconds) 5120 (500 Mbps)

Ethernet 25,600 (1 ms) 256,000 (10 Mbps)

T-1 (1.544 Mbps) 512,000 (20,000 ms) 1,657,856

64 kbps 512,000 40,000,000

56 kbps 512,000 45,714,176

As with IGRP, the metric weights subcommand changes EIGRP metric computation. The k
values in the EIGRP composite metric formula can be changed to select EIGRP metrics. The
command to change the k values is the metric weights tos k1 k2 k3 k4 k5 subcommand under
router eigrp n . You never use the tos value, which is always set to 0. The other arguments are
set to 1 or 0 to alter the composite metric. If you want the EIGRP composite metric to use all
the parameters, the command is as follows:

router eigrp n
metric weights 0 1 1 1 1 1

EIGRP Packet Types
EIGRP uses the following packet types:
•

Hello

•

Acknowledgment

•

Update

•

Query

•

Reply

Hello packets assist in the discovery of EIGRP neighbors. The packets are multicast to
224.0.0.10. By default, hello packets are sent every 5 seconds (60 seconds on WAN links
with 1544 Mbps speeds or less).

An acknowledgment packet acknowledges the reception of an update packet. An acknowledg-
ment packet is a hello packet with no data. Acknowledgment packets are sent to the unicast
address of the sender of the update packet.

Update packets contain the routing information of destinations. Update packets are unicast to
newly discovered neighbors; otherwise, update packets are multicast to 224.0.0.10 when a link