
When configuring [EIGRP](/eigrp), it is possible to apply [summarization globally](/eigrp-auto-summary) or on a per interface basis.  The latter allows for more granularity in the configuration of EIGRP and the way in which routes are shared with specific EIGRP neighbors.

This can be configured using the `ip summary-address eigrp` interface configuration command.  For example, the following two commands cause any EIGRP updates sent out of FastEthernet 0/0 to be summarized as indicated:

```
R1(config)#interface fastEthernet 0/0
R1(config-if)#ip summary-address eigrp 1 172.16.0.0 255.255.0.0
R1(config-if)#ip summary-address eigrp 1 10.10.0.0 255.255.0.0
```

If the subnet mask is not indicated, then the [classful subnet mask](/ipv4-classful-addressing) will be used.  Multiple summary addresses can be applied to a single interface.

## Links

https://networklessons.com/eigrp/how-to-configure-eigrp-summarization

EIGRP - Summarization per interface

DNS - Caching

DNS - Recursive Resolver

DNS - What is a delegation zone

DNS - stub zone

DNS - understanding zones

DNS cache windows PC

DSL - Asymmetric Digital Subscriber Line (ADSL)

DTP - Sending of Frames

DTP - best practice to disable

DTP - how to disable

Debug Condition Command Restrictions in Cisco IOS

Debug IP Routing

Decrypt IPSec ESP traffic with Wireshark

Demand Circuits

Demarcation point

Difference between per-prefix LFA and per-link based LFA

Differences between CCIE and CCDE lab exams

Diffserv recommended configuration

Distribute-lists - using route maps to set attributes

Distribute-lists and named extended ACLs

ECMP Multicast Routing Cisco Nexus Switches

EEM - action mail

EEM - exit status variable

EEM Cisco Embedded Event Manager

EEM Matching a string within CLI output

EEM sync and skip keywords

EIGRP - Advertised metric is cumulative

EIGRP - Advertising a route using the network command

EIGRP - DUAL Algorithm and FD Set to Infinity

EIGRP - External routes from different ASes

EIGRP - Feasible Successors and the DUAL Algorithm

EIGRP - Hello interval and Hold time

EIGRP - Hop Count

EIGRP - Message TTL value of 2

EIGRP - Metric Equation Multipliers

EIGRP - Network command syntax

EIGRP - Queries

EIGRP - RTP's reliable message exchange process

EIGRP - Reliable Multicast

EIGRP - Router ID and loop prevention

EIGRP - SIA Process and RTP retry attempts

EIGRP - Source of values for metric calculation

EIGRP - Static neighbors over any L2 technology

EIGRP - Stub Router

EIGRP - Stub default behavior

EIGRP - Stub router types

EIGRP - Understanding Advertised Distance (AD)

EIGRP - Update message exchange process

EIGRP - Viewing RTP in Wireshark

EIGRP - af-interface configuration mode

EIGRP - how metrics are sent in updates

EIGRP - internal vs external routes

EIGRP - metric computation method

EIGRP - metric equation

EIGRP - named mode name

EIGRP - network command with no wildcard mask

EIGRP - redistribute connected and static routes

EIGRP - shutdown command

EIGRP - stub site function

EIGRP Create and advertise a default route

EIGRP Feasibility condition

EIGRP Header

EIGRP IP bandwidth-percent example

EIGRP Implementation by Non-Cisco Vendors

EIGRP LFA FRR

EIGRP Refining the behavior of load balancing with traffic-share

EIGRP SIA timers

EIGRP Useful Debug Commands

EIGRP authentication

EIGRP auto-summary

EIGRP change rib scale

EIGRP establishing remote neighbors

EIGRP header - ACK field

EIGRP named mode

EIGRP on the Nexus Platform

EIGRP redistributing named mode

EIGRP rib-scale

EIGRP seed metrics when redistributing

EIGRP split horizon verification

EIGRP split-horizon vs poison reverse

EIGRP unequal cost load balancing

EIGRP what happens when a feasible successor fails

EIGRP

EPC - Cisco Embedded Packet Capture

ERSPAN

EVE-NG supported Cisco and other vendor images

Equal-cost Multi-path routing

EtherChannel - Converting an L2 EtherChannel to L3

EtherChannel - LACP System ID

EtherChannel - LACP fast-switchover

EtherChannel - Load Balancing on CatOS

EtherChannel - Load balancing algorithm applied globally and per portchannel

EtherChannel - Maximum Number of Physical Links

EtherChannel - PAgP timer, hello interval, and age value

EtherChannel - Troubleshooting on Cisco IOS Switches

EtherChannel - Understanding LACP port and system priorities