Network Design and Configuration for ABC and XYZ Location Preferences

Abstract

Introduction

I. OVERVIEW

This document describes the network configuration changes required to ensure that certain locations prefer ABC for the default route while others prefer XYZ. The configurations include IP SLA for reachability tracking, route maps for policy-based routing, and EIGRP redistribution of static routes with adjusted metrics to control route preferences.

A. Pre-Requisite

1. Ensure backups are taken for all respective devices before applying configuration changes.
2. Confirm that static routes have been removed from both ISR and ASR routers.
3. Verify that the redistribute connected command is configured under EIGRP.

B. ABC Location Configuration

The ABC location will prefer the default route when the specified conditions are met.

C. IP SLA Configuration for ABC

Bash (Copy code)

ip sla 1

 icmp-echo <IP_to_track> source-ip <IP_ADDRESS>

 timeout 9000

 frequency <Frequency>

!

ip sla schedule 1 life forever start-time now

!

track 1 ip sla 1 reachability

!

track 2 ip route 0.0.0.0 0.0.0.0 reachability

!

track 3 list Boolean and

    object 1

    object 2

D. Default Route Configuration

bash

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ip route 0.0.0.0 0.0.0.0 <ABC_Next-hop_IP> tag 1 track 3

ip route 8.8.8.8 255.255.255.255 <Next-hop> tag 1 track 1

E. Redistribution and Route Map for ABC

bash

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redistribute static metric 10000 1000 255 1 1500 route-map STATIC->EIGRP

!

route-map STATIC->EIGRP permit 10

    match tag 1

!

router eigrp <AS>

    redistribute static route-map STATIC->EIGRP

F. XYZ Location Configuration

The XYZ location will prefer the default route when the specified conditions are met.

IP SLA Configuration for XYZ:

bash

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ip sla 1

 icmp-echo <IP_to_track> source-ip <IP_ADDRESS>

 timeout 9000

 frequency <Frequency>

!

ip sla schedule 1 life forever start-time now

!

track 1 ip sla 1 reachability

!

track 2 ip route 0.0.0.0 0.0.0.0 reachability

!

track 3 list Boolean and

    object 1

    object 2

G. Default Route Configuration

bash

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ip route 8.8.8.8 255.255.255.255 <Next-hop> tag 9 track 1

ip route 0.0.0.0 0.0.0.0 <XYZ_Next-hop_IP> tag 9 track 3

H. Redistribution and Route Map for XYZ

bash

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redistribute static metric 10000 100 255 1 1500 route-map STATIC->EIGRP

!

route-map STATIC->EIGRP permit 10

    match tag 9

!

router eigrp <AS>

    redistribute static route-map STATIC->EIGRP

II. POLICY-BASED ROUTING AND ROUTE MAP FOR TAGGING AND REDISTRIBUTION

A. Subnet-Based Routing Configuration

bash

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ip prefix-list SUBNET-A seq 5 permit <Subnet-A_IP>/xx

ip prefix-list SUBNET-B seq 5 permit <Subnet-B_IP>/xx

!

route-map ADV permit 10

    match ip address prefix-list SUBNET-A

    set tag 500

!

route-map ADV permit 20

    match ip address prefix-list SUBNET-B

    set tag 1000

!

router eigrp <AS>

    redistribute connected route-map ADV

B. ABC Side Route Map for Tagging

bash

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route-map <NAME> permit 10

    match tag 500

!

route-map <NAME> deny 20

    match tag 1000

!

route-map <NAME> permit 30

!

router eigrp <AS>

    distribute-list route-map <NAME> in

C. XYZ Side Route Map for Tagging

bash

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route-map <NAME> permit 10

    match tag 1000

!

route-map <NAME> deny 20

    match tag 500

!

route-map <NAME> permit 30

!

router eigrp <AS>

    distribute-list route-map <NAME> in

D. Testing and Monitoring

For testing the configurations, use the following commands to verify the IP SLA and track status:

bash

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show track

show ip sla statistics

This will help confirm that the routes are correctly preferred according to the SLA conditions and that tracking is functional.

III. CONCLUSION

These configurations ensure that:

1. Subnet A accesses the internet through ABC.
2. Subnet B accesses the internet through XYZ.
3. The default route will be dynamically adjusted based on the availability of the monitored routes, allowing failover if one path goes down.
4. EIGRP and redistribution mechanisms are properly configured with route maps and appropriate metrics for optimal path selection.

Please proceed with applying the configurations as outlined. Make sure to validate the setup using the testing commands provided, and monitor the network to ensure the desired behavior.

Copyright

Copyright © 2024 Pradip Suresh Patole. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.