Eigrp default route (IP default-gateway mode)

Eigrp default route

The effect of the EIGRP default route was not made yesterday (IP default-gateway mode)

Topology:

650) this.width=650; "title=" clip_image002[4] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "Alt=" Clip_ IMAGE002[4] "src=" http://s3.51cto.com/wyfs02/M02/6B/BF/wKioL1U2JZvRFZcsAACBr3nCMzA033.jpg "border=" 0 "height=" 265 "/>

I carefully recalled the course of the teacher's operation at that time. (yy a sentence: In the course I did not take too seriously, always think that the teacher is the 3.3.3.3 as an Internet network, so I always say that the teacher's configuration is wrong, in fact, he is the 23.0.0.0 can start as an Internet network, 3.3.3.3 is a follow-up network)

The teacher's configuration is as follows:

R1:eigrp

650) this.width=650; "title=" clip_image004[4] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "Alt=" Clip_ IMAGE004[4] "src=" http://s3.51cto.com/wyfs02/M00/6B/BF/wKioL1U2JZuAI9VDAAA09zrwPck231.jpg "border=" 0 "height=" 93 " />

R2:eigrp,ip route, IP default-gateway, IP route 3.0.0.0

650) this.width=650; "title=" clip_image006[4] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "Alt=" Clip_ IMAGE006[4] "src=" http://s3.51cto.com/wyfs02/M01/6B/BF/wKioL1U2JZ3QAcx5AABG5ZWzHGQ299.jpg "border=" 0 "height=" 112 "/>

650) this.width=650; "title=" clip_image008[4] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "Alt=" Clip_ IMAGE008[4] "src=" http://s3.51cto.com/wyfs02/M02/6B/BF/wKioL1U2JZ6ij0yyAAAuBTM2cKs924.jpg "border=" 0 "height=" 47 " />

650) this.width=650; "title=" clip_image010[4] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "Alt=" Clip_ IMAGE010[4] "src=" http://s3.51cto.com/wyfs02/M00/6B/BF/wKioL1U2JZ-jB5eaAAAcrVS-Jak568.jpg "border=" 0 "height=" 29 " />

R3: A way back.

650) this.width=650; "title=" clip_image012[4] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "Alt=" Clip_ IMAGE012[4] "src=" http://s3.51cto.com/wyfs02/M01/6B/BF/wKioL1U2JaDg1fbDAAAn4yq2Z9M976.jpg "border=" 0 "height=" 30 " />

The routing table for R1 and R2 is as follows:

650) this.width=650; "title=" clip_image014[4] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "Alt=" Clip_ IMAGE014[4] "src=" http://s3.51cto.com/wyfs02/M02/6B/BF/wKioL1U2JaKjmzIeAAFXOQI-ejM980.jpg "border=" 0 "height=" 242 "/>

650) this.width=650; "title=" clip_image016[4] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "Alt=" Clip_ IMAGE016[4] "src=" http://s3.51cto.com/wyfs02/M00/6B/BF/wKioL1U2JaXxmOxsAAHOoVVxGx8113.jpg "border=" 0 "height=" 318 "/>

Take a closer look at the 3.0.0.0 route, which is learned from the static

650) this.width=650; "title=" clip_image018[4] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "Alt=" Clip_ IMAGE018[4] "src=" http://s3.51cto.com/wyfs02/M01/6B/BF/wKioL1U2JaaDD2yrAAB_I0t64bs842.jpg "border=" 0 "height=" 103 "/>

Well, the teacher's question came: why is it always on the R1 to see the d* Route

The reason why I have found the answer in the Cisco Forum abroad:

https://learningnetwork.cisco.com/thread/58691

The workaround is to change the default route to:

R2 (config) #ip Route 3.0.0.0 255.0.0.0 s1/0

Look at the 3.0.0.0 route on the R2:

650) this.width=650; "title=" clip_image020[4] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "Alt=" Clip_ IMAGE020[4] "src=" http://s3.51cto.com/wyfs02/M02/6B/C3/wKiom1U2JEzCpv8LAACNCpWfmsY596.jpg "border=" 0 "height=" 115 "/>

As a result, I saw a route to D * on R1.

650) this.width=650; "title=" clip_image022 "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;border-left:0px;padding-right:0px, "alt=" clip_image022 "src=" Http://s3.51cto.com/wyfs02/M02/6B/C3/wKiom1U2JE7QCA1zAAFv7Cc9K5A251.jpg "border=" 0 "height=" 258 "/>

Test environment iOS Version:version 12.4 (one) T2

Summary: IP route 0.0.0.0 0.0.0.0 interface will result in EIGRP redistribution routes. To meet the three conditions the teacher said

This is also explained in TCP IP Volume two.

This article is from "Eric's Mind Journey" blog, declined reprint!

Eigrp default route (IP default-gateway mode)