Introduction

The exercise is part of case study describing IPX routing in Great Coals network shown below:

To improve the EIGRP convergence and stability in the network, the network design uses hierarchical default routing. Please refer to "Case Study - GreatCoals network" in Chapter 10 for more details. Solving Exercise 10-2 is a prerequisite for this exercise.

Exercise

How could you improve the GreatCoals design to solve the low-speed international link bottleneck?

Solution

There are two possible solutions for this exercise:

• Deploy another IPX EIGRP process between Austin router and international sales offices. This solution is not optimal as a failure of one low-speed international link will involve all international sales offices in diffusing computation.
• Use IPX EIGRP between Austin router and international sales offices only to propagate SAP information and use IPX RIP for routing updates. With this setup, the Austin router will never query international sales offices when running diffusing computation.

The router configuration command needed to implement the second solution are as follows:

hostname Core-7576
!
ipx routing
ipx internal-network FFFFFF01
!
interface serial 1/2/3
 description Link toward China
 ipx network 12345
 ipx sap-incremental eigrp 131 rsup-only
 ipx advertise-default-route-only 12345
! 
ipx router eigrp 131
 network all
 distribute-list DefaultOnly out
!
ipx router rip
 network 12345

corresponding commands on the China router are

hostname China
!
ipx routing
!
interface serial 0
 description Link toward Austin
 ipx network 12345
 ipx sap-incremental eigrp 131 rsup-only
! 
ipx router eigrp 131
 network all
!
ipx router rip
 network 12345